Liquid crystal display device
Abstract
To provide a liquid crystal display device suitable for a thin film transistor which uses an oxide semiconductor. In a liquid crystal display device which includes a thin film transistor including an oxide semiconductor layer, a film having a function of attenuating the intensity of transmitting visible light is used as an interlayer film which covers at least the oxide semiconductor layer. As the film having a function of attenuating the intensity of transmitting visible light, a coloring layer can be used and a light-transmitting chromatic color resin layer is preferably used. An interlayer film which includes a light-transmitting chromatic color resin layer and a light-blocking layer may be formed in order that the light-blocking layer is used as a film having a function of attenuating the intensity of transmitting visible light.
Term
No projected expiry on record.
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21 claims: 21 independent, 0 dependent
- 1一種顯示裝置,包括:薄膜電晶體,包括:閘極電極層;第一絕緣層,在該閘極電極層之上;含有氧化物半導體的通道形成區,該通道形成區係在該第一絕緣層之上且與該閘極電極層重疊;n型區,包含源極區和汲極區的其中一者;以及第二絕緣層,在該通道形成區之上;像素電極層,係電性連接至該薄膜電晶體;彩色透光樹脂層,在該薄膜電晶體及該像素電極層之間;顯示層,在該薄膜電晶體、該像素電極層及該彩色透光樹脂層之上;以及電極層,在該第二絕緣層之上且與該閘極電極層及該通道形成區重疊,其中,該通道形成區係包含在半導體層中,其中,該n型區包含各自具有1nm至10nm之直徑的晶體,其中,該彩色透光樹脂層具有低於該半導體層之透光率的透光率,其中,該彩色透光樹脂層覆蓋該通道形成區和該n型區,其中,該閘極電極層含有銅, 其中,該第一絕緣層為包含第一層及第二層的疊層,其中,該第一層為與該第二層不同的層,其中,該第一層含有矽及氮,其中,該第二層含有矽及氧,其中,該氧化物半導體含有銦、鎵及鋅,其中,該n型區含有銦、鎵、鋅及氧,其中,該第二絕緣層含有矽及氧,且其中,在平行於該薄膜電晶體的通道長度方向的方向上,該閘極電極層的長度大於該半導體層的長度。
- 2如申請專利範圍第1項的顯示裝置,其中,該彩色透光樹脂層具有複數個顏色,且其中,在該顯示裝置中的各個像素包括具有該複數個顏色中之一者的該彩色透光樹脂層。
- 3如申請專利範圍第1項的顯示裝置,其中,遮光層在該薄膜電晶體之上而在其之間插置有該顯示層。
- 4如申請專利範圍第1項的顯示裝置,其中,該電極層為共同電極層,且其中,該共同電極層係包含於該彩色透光樹脂層及該顯示層之間。
- 5如申請專利範圍第1項的顯示裝置,其中,該電極層為共同電極層,其中,該共同電極層係包含於該彩色透光樹脂層及該顯示層之間,且其中,該像素電極層及該共同電極層具有開口圖案。
- 6如申請專利範圍第1項的顯示裝置,其中,該電極層為共同電極層,其中,該共同電極層係包含於該彩色透光樹脂層及該顯示層之間,且其中,該像素電極層及該共同電極層具有梳齒形狀。
- 7如申請專利範圍第1項的顯示裝置,其中,該顯示層為液晶層。
- 8如申請專利範圍第7項的顯示裝置,其中,該液晶層包括呈現藍相的液晶材料。
- 9如申請專利範圍第7項的顯示裝置,其中,該液晶層包括手性試劑。
- 10如申請專利範圍第7項的顯示裝置,其中,該液晶層包括光固化樹脂及光聚合引發劑。
- 11如申請專利範圍第1項的顯示裝置,其中,該彩色透光樹脂層與該像素電極層重疊。
- 12如申請專利範圍第1項的顯示裝置,另包括在該彩色透光樹脂層之上的透明絕緣層。
- 13如申請專利範圍第1項的顯示裝置,其中,該n型區係包含在該半導體層之上的n型層中。
- 14一種顯示裝置,包括:薄膜電晶體,包括:閘極電極層;第一絕緣層,在該閘極電極層之上;通道形成區,該通道形成區在該第一絕緣層之上 且與該閘極電極層重疊;n型區,包含源極和汲極的其中一者;源極電極及汲極電極,在包含氧化物半導體的該通道形成區之上;以及第二絕緣層,在該通道形成區之上;彩色透光樹脂層,在該第二絕緣層之上;第三絕緣層,在該彩色透光樹脂層之上且與該彩色透光樹脂層直接接觸;像素電極層,電性連接至該薄膜電晶體的該源極電極及該汲極電極中之一者;以及電極層,在該第二絕緣層之上且與該閘極電極層及該通道形成區重疊,其中,該通道形成區係包含在半導體層中,其中,該n型區包含各自具有1nm至10nm之直徑的晶體,其中,該彩色透光樹脂層具有低於該半導體層之透光率的透光率,其中,該彩色透光樹脂層覆蓋該通道形成區和該n型區,其中,該第一絕緣層為包含第一層及第二層的疊層,其中,該第一層為與該第二層不同的層,其中,該第一層含有矽及氮,其中,該第二層含有矽及氧,其中,該氧化物半導體含有銦、鎵及鋅, 其中,該第二絕緣層含有矽及氧,其中,該n型區含有銦、鎵、鋅及氧,其中,該像素電極層含有氧化銦錫,且其中,在平行於該薄膜電晶體的通道長度方向的方向上,該閘極電極層的長度大於該半導體層的長度。
- 15如申請專利範圍第14項的顯示裝置,另包括在該第三絕緣層之上的顯示層。
- 16如申請專利範圍第15項的顯示裝置,其中,該顯示層為液晶層。
- 17如申請專利範圍第14項的顯示裝置,其中,該閘極電極層含有銅。
- 18如申請專利範圍第14項的顯示裝置,其中,該源極電極及該汲極電極含有鉬和鈦。
- 19如申請專利範圍第14項的顯示裝置,其中,該彩色透光樹脂層具有複數個顏色,且其中,在該顯示裝置中的各個像素包括具有該複數個顏色中之一者的該彩色透光樹脂層。
- 20如申請專利範圍第14項的顯示裝置,其中,該電極層為共同電極層,且其中,該共同電極層在該第三絕緣層之上。
- 21如申請專利範圍第14項的顯示裝置,其中,該n型區係包含在該半導體層之上的n型層中。
Independent claims21
265 paragraphs, as filed
Liquid crystal display device
Liquid crystal display device
The present invention relates to a liquid crystal display device using an oxide semiconductor and a manufacturing method thereof.
Thin film transistors formed on flat plates such as glass substrates, typified by liquid crystal display devices, are manufactured using amorphous silicon or polycrystalline silicon. Thin-film transistors using amorphous silicon have the following characteristics: Although their field-effect mobility is low, they can correspond to a larger area of a glass substrate. On the other hand, thin-film transistors using crystalline silicon have the following characteristics: Although their field-effect mobility is high, they require crystallization processes such as laser annealing, so they are not necessarily suitable for large-area glass substrates.
On the other hand, the technology of manufacturing thin film transistors using oxide semiconductors and applying them to electronic devices and optical devices has attracted attention. For example, Patent Document 1 and Patent Document 2 disclose technologies that use zinc oxide or In-Ga-Zn-O-based oxide semiconductors as oxide semiconductor films to produce thin-film transistors and use them for switching elements of image display devices. .
Thin film transistors with channel formation regions in oxide semiconductors can be In order to achieve higher field-effect mobility than thin film transistors using amorphous silicon. The oxide semiconductor film can be formed at a temperature below 300 degrees by a sputtering method or the like, and its manufacturing process is simpler than that of a thin film transistor using polysilicon.
Since the oxide semiconductor is a transparent semiconductor that transmits light of a wavelength in the visible light region, a high aperture ratio can be achieved by using it in a pixel of a display device.
It is expected that this oxide semiconductor will be used to form thin film transistors on glass substrates, plastic substrates, etc., and be applied to display devices.
[Patent Document 1] Japanese Patent Application Publication No. 2007-123861
[Patent Document 2] Japanese Patent Application Publication No. 2007-96055
Therefore, an object of the present invention is to provide a liquid crystal display device suitable for applying a thin film transistor of an oxide semiconductor.
In a liquid crystal display device having a thin film transistor including an oxide semiconductor layer, at least an interlayer film covering the oxide semiconductor layer uses a film capable of attenuating the light intensity of visible light transmitted therethrough. A film capable of attenuating the light intensity of visible light transmitted therethrough has a lower transmittance of visible light than the oxide semiconductor layer. As a film capable of reducing the light intensity of visible light transmitted therethrough, a colored layer can be used, and a colored light-transmitting resin layer is preferably used. In addition, an interlayer film including a colored light-transmitting resin layer and a light-shielding layer is used, and a light-shielding layer may also be used as a film capable of reducing the light intensity of visible light transmitted therethrough.
When the colored layer of the colored light-transmitting resin layer is used as a thin film transistor In the case of the upper interlayer film, the intensity of the light incident on the semiconductor layer of the thin film transistor can be reduced without reducing the aperture ratio of the pixel, thereby preventing damage due to the sensitivity of the oxide semiconductor. The resulting change in the electrical characteristics of the thin film transistor stabilizes it. In addition, the color light-transmitting resin layer can also be used as a color filter layer. When a color filter layer is provided on the opposing substrate side, there is a concern that it is difficult to accurately align the pixel area with the element substrate on which thin film transistors are formed, resulting in a decrease in image quality. The film is directly formed on the side of the element substrate as a color filter layer to more accurately control the formation area, and can correspond to pixels with fine patterns. In addition, since the same insulating layer is used as the interlayer film and the color filter layer, the manufacturing process is simplified and the liquid crystal display device can be manufactured at a lower cost.
Color refers to colors other than achromatic colors such as black, gray, and white. Since a colored light-transmitting resin layer is used as a color filter, it is formed using a material that transmits only colored light. As for the color, red, green, blue, etc. can be used. In addition, cyan, magenta, yellow, etc. can also be used. Transmitting only colored colored light means that the light transmitted through the colored light-transmitting resin layer has a peak in the wavelength of the colored light.
As the color light-transmitting resin layer is used as a color filter layer, it is possible to appropriately control the most suitable thickness in consideration of the relationship between the concentration of the coloring material contained and the transmittance of light. When a laminate of a plurality of thin films is used as an interlayer film, as long as at least one layer is a colored light-transmitting resin layer, it can be used as a color filter.
When the thickness is different according to the color of the color or there are surface irregularities caused by the thin film transistor, an insulating layer capable of transmitting light of a wavelength in the visible light region (that is, so-called colorless and transparent) can be laminated to make the surface of the interlayer film flat change. By improving the flatness of the interlayer film, the coverage of the pixel electrode layer and the common electrode layer formed thereon is improved, and the gap (thickness) of the liquid crystal layer can be made uniform, thereby further improving the visibility of the liquid crystal display device To achieve high image quality.
When the light-shielding layer (black matrix) is used as the interlayer film provided on the thin-film transistor, the light-shielding layer can block the incidence of light to the semiconductor layer of the thin-film transistor, and therefore has the ability to prevent the sensitivity due to the oxide semiconductor The resulting change in the electrical characteristics of the thin film transistor stabilizes it. In addition, since the light shielding layer can also prevent light leakage to adjacent pixels, higher contrast and high-definition display can be performed. Therefore, high definition and high reliability of the liquid crystal display device can be realized.
In this specification, the substrate on which the thin film transistor, the pixel electrode layer, the common electrode layer, and the interlayer film are formed is called the element substrate (first substrate), and the substrate facing the element substrate through the liquid crystal layer is called Used as a counter substrate (second substrate).
The light shielding layer may be formed on the counter substrate side or the element substrate side of the liquid crystal display device. It can further improve the contrast or improve the stability of the thin film transistor. By forming the light shielding layer on the region corresponding to the thin film transistor (at least the region overlapping with the semiconductor layer of the thin film transistor), it is possible to prevent changes in the electrical characteristics of the thin film transistor caused by light incident from the counter substrate. When the light-shielding layer is formed on the opposite substrate side, it can be formed on the A region corresponding to the thin film transistor (at least the region overlapping with the semiconductor layer of the thin film transistor) via the liquid crystal layer. When the light-shielding layer is formed on the element substrate side, it may be formed directly on the thin film transistor (at least the region covering the semiconductor layer of the thin film transistor), or may be formed via an insulating layer.
When a light-shielding layer is also provided on the opposite substrate side, the semiconductor layer of the thin film transistor may block the light from the element substrate and the light from the opposite substrate through the light-shielding wiring layer or electrode layer, so it is not necessary The light-shielding layer must be formed to cover the thin-film transistor.
An embodiment of the structure of the invention disclosed in this specification includes: using an oxide semiconductor layer overlapping the gate electrode layer as a thin film transistor in the channel formation region; a pixel electrode layer electrically connected to the thin film transistor; and disposing The interlayer film between the thin film transistor and the pixel electrode layer; and, the liquid crystal layer disposed on the thin film transistor, the pixel electrode layer, and the interlayer film, wherein the interlayer film is a color whose light transmittance is lower than that of the oxide semiconductor layer The light-transmitting resin layer, and the color light-transmitting resin layer is provided so as to cover the oxide semiconductor layer while overlapping with the pixel electrode layer.
Another embodiment of the structure of the invention disclosed in this specification includes: using an oxide semiconductor layer overlapping the gate electrode layer as a thin film transistor in the channel formation region; and a pixel electrode layer electrically connected to the thin film transistor; An interlayer film disposed between the thin film transistor and the pixel electrode layer; and, a liquid crystal layer disposed on the thin film transistor, the pixel electrode layer, and the interlayer film, wherein the interlayer film includes a layer with a lower light transmittance than the oxide semiconductor layer The color light-transmitting resin layer and the light-shielding layer, and the light-shielding layer is provided to cover the oxide semiconductor layer, and the color light-transmitting resin layer is overlapped with the pixel electrode layer. Is set in a stacked manner.
In addition, ordinal numbers such as first and second are added for convenience in this specification. Therefore, they do not represent the process sequence or stacking sequence of the invention. In addition, it does not indicate the unique name of the matter of the specific invention in this specification.
In addition, in this specification, semiconductor devices refer to all devices that can be operated by utilizing semiconductor characteristics, and therefore electro-optical devices, semiconductor circuits, and electronic devices are all semiconductor devices.
In a liquid crystal display device having a thin film transistor using an oxide semiconductor layer as a channel, at least the interlayer film covering the oxide semiconductor layer is formed with a material capable of reducing the light intensity of visible light transmitted therethrough. In the case of affecting the aperture ratio, the operating characteristics of the thin film transistor are stabilized.
<p>200First substrate</p><p>201Second substrate</p><p>202aSealing material</p><p>202bSealing material</p><p>203Component layer</p><p>204Transparent resin layer</p><p>204aTransparent resin layer</p><p>204bTransparent resin layer</p><p>204cTransparent resin layer</p><p>205Shading layer</p><p>205aShading layer</p><p>205bShading layer</p><p>205cShading layer</p><p>205dShading layer</p><p>206Liquid crystal layer</p><p>207Light</p><p>208Liquid crystal layer</p><p>209Interlayer film</p><p>210aPolarizer</p><p>210bPolarizer</p><p>211Insulation film</p><p>220Thin Film Transistor</p><p>221Gate electrode layer</p><p>222Gate insulation layer</p><p>223Semiconductor layer</p><p>224an<sup>+</sup>Floor</p><p>224bn<sup>+</sup>Floor</p><p>225awiring layer</p><p>225bwiring layer</p><p>230Pixel electrode layer</p><p>401Gate electrode layer</p><p>402Gate insulation layer</p><p>403Semiconductor layer</p><p>404an<sup>+</sup>Floor</p><p>404bn<sup>+</sup>Floor</p><p>405awiring layer</p><p>405bwiring layer</p><p>407Insulation film</p><p>408Common wiring layer</p><p>410wiring layer</p><p>413Interlayer film</p><p>414Shading layer</p><p>415Insulation layer</p><p>416Insulation film</p><p>417Transparent resin layer</p><p>420Thin Film Transistor</p><p>421Thin Film Transistor</p><p>422Thin Film Transistor</p><p>423Thin Film Transistor</p><p>441First substrate</p><p>442Second substrate</p><p>443a Polarizing plate</p><p>443bPolarizer</p><p>444Liquid crystal layer</p><p>446Second electrode layer</p><p>446aSecond electrode layer</p><p>446bSecond electrode layer</p><p>446cSecond electrode layer</p><p>446dSecond electrode layer</p><p>447First electrode layer</p><p>447aFirst electrode layer</p><p>447bFirst electrode layer</p><p>447cFirst electrode layer</p><p>447dFirst electrode layer</p><p>455awiring layer</p><p>455bwiring layer</p><p>1000Mobile phone</p><p>1001Shell</p><p>1002Display</p><p>1003Operation button</p><p>1004External port</p><p>1005Speaker</p><p>1006Microphone</p><p>2600Component substrate</p><p>2601Opposite substrate</p><p>2602Sealing material</p><p>2603Component layer</p><p>2604Display element</p><p>2605Interlayer film</p><p>2606Polarizer</p><p>2607Polarizer</p><p>2608Wiring circuit department</p><p>2609flexible circuit board</p><p>2610Cold cathode tube</p><p>2611Reflector</p><p>2612Circuit board</p><p>2613Diffuser plate</p><p>4001First substrate</p><p>4002Pixel</p><p>4003Signal line drive circuit</p><p>4003aSignal line drive circuit</p><p>4003bSignal line drive circuit</p><p>4004Scan line drive circuit</p><p>4005Sealing material</p><p>4006Second substrate</p><p>4008Liquid crystal layer</p><p>4010Thin Film Transistor</p><p>4011Thin Film Transistor</p><p>4013Liquid crystal element</p><p>4015Connecting terminal electrode</p><p>4016Terminal electrode</p><p>4018Flexible Printed Circuit (FPC)</p><p>4019Anisotropic conductive film</p><p>4020Insulation layer</p><p>4021Interlayer film</p><p>4030Pixel electrode layer</p><p>4031Common electrode layer</p><p>4032Polarizer</p><p>4034Shading layer</p><p>9400Communication device</p><p>9401Shell</p><p>9402Operation button</p><p>9403External input terminal</p><p>9404Mike</p><p>9405Speaker</p><p>9406Light-emitting part</p><p>9410Display device</p><p>9411Shell</p><p>9412Display</p><p>9413Operation button</p><p>9600TV installation</p><p>9601Shell</p><p>9603Display</p><p>9605Support</p><p>9607Display</p><p>9609Operation keys</p><p>9610Remote control</p><p>9700Digital Photo Frame</p><p>9701Shell</p><p>9703Display</p><p>9881Shell</p><p>9882Display</p><p>9883Display</p><p>9884Speaker Department</p><p>9885Operation keys</p><p>9886Recording media insertion section</p><p>9887Connecting terminal</p><p>9888Sensor</p><p>9889Microphone</p><p>9890LED light</p><p>9891Shell</p><p>9893Connecting part</p><p>9900Slot Machine</p><p>9901Shell</p><p>9903Display</p>
In the drawings: FIG. 1 is a diagram illustrating a liquid crystal display device; FIG. 2 is a diagram illustrating a liquid crystal display device; FIGS. 3A and 3B are diagrams illustrating a liquid crystal display device; FIGS. 4A and 4B are diagrams illustrating a liquid crystal display device; 5A and 5B are diagrams illustrating a liquid crystal display device; FIGS. 6A and 6B are diagrams illustrating a liquid crystal display device; FIGS. 7A and 7B are diagrams illustrating a liquid crystal display device; FIGS. 8A to 8D are diagrams illustrating electrode layers of the liquid crystal display device; 9A and 9B are diagrams illustrating a liquid crystal display device; Figures 10A and 10B are diagrams illustrating a liquid crystal display device; Figures 11A and 11B are diagrams illustrating a liquid crystal display device; Figures 12A1, 12A2, and 12B are diagrams illustrating a liquid crystal display device; Figures 13A and 13B are diagrams illustrating a television device and a digital photo frame Figures 14A and 14B are external views showing an example of a game machine; Figures 15A and 15B are external views showing an example of a mobile phone; Figure 16 is a diagram illustrating a liquid crystal display module; 17A and 17B are diagrams illustrating the liquid crystal display device; FIGS. 18A and 18B are diagrams illustrating the liquid crystal display device; and FIGS. 19A to 19D are diagrams illustrating the manufacturing method of the liquid crystal display device.
The embodiment mode will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. Those of ordinary skill in the art can easily understand the fact that the modes and details can be changed into various forms without departing from the spirit and scope of the present invention. . Therefore, it should not be interpreted as being limited to the description of the embodiment modes shown below. Note that in the structure described below, the same parts or parts with the same functions are denoted by the same reference numerals in different drawings, and repeated descriptions are omitted.
Example Mode 1
The liquid crystal display device and the method of manufacturing the liquid crystal display device will be described with reference to FIGS. 1, 2, and FIGS. 17A and 17B.
Fig. 1, Fig. 2 and Figs. 17A and 17B are cross-sectional views of a liquid crystal display device.
In FIGS. 1 and 2, an element layer 203 is formed on the first substrate 200 of the element substrate (refer to FIGS. 17A and 17B), an interlayer film 209 is formed on the element layer 203, and an interlayer film 209 is provided on the interlayer film 209. There is a pixel electrode layer 230. The pixel electrode layer 230 and the counter electrode layer 231 formed on the second substrate 201 of the counter substrate are sealed so as to sandwich the liquid crystal layer 208.
In the mode of the liquid crystal display device of FIG. 1, a plurality of pixels are arranged in a matrix, and the pixels include: a thin film transistor including an oxide semiconductor layer; an interlayer film on the thin film transistor; and pixels on the interlayer film An electrode layer; and a liquid crystal layer above the pixel electrode layer, wherein the interlayer film is a color translucent resin layer.
The element layer 203 (refer to FIGS. 17A and 17B) is provided with a plurality of pixels arranged in a matrix, and the pixel has a thin film transistor 220 including an oxide semiconductor layer. The thin film transistor 220 is an inverted staggered thin film transistor. It includes a gate electrode layer 221, a gate insulating layer 222, and a semiconductor layer 223 on the first substrate 200 of the substrate with an insulating surface. N of the pole region or the drain region<sup>+</sup>The layers 224a, 224b, and the wiring layers 225a, 225b serving as source electrode layers or drain electrode layers. In addition, the thin film transistor 220 is covered by the insulating film 227.
In the liquid crystal display device of FIG. 1, as the interlayer film 209, the color light-transmitting resin layer 204 of a film capable of reducing the light intensity of visible light transmitted therethrough is used. The visible light transmittance of the color light-transmitting resin layer 204 is lower than the visible light transmittance of the semiconductor layer 223 of the oxide semiconductor layer.
When the colored layer of the color light-transmitting resin layer is used as the interlayer film 209 disposed on the thin film transistor 220, it is possible to reduce the incidence of the semiconductor layer 223 of the thin film transistor 220 without reducing the aperture ratio of the pixel. The intensity of light can thereby play a role in preventing and stabilizing the electrical characteristics of the thin film transistor 220 caused by the sensitivity of the oxide semiconductor. In addition, the color light-transmitting resin layer can also be used as a color filter layer. When a color filter layer is provided on the opposite substrate side, although there is a concern that it is difficult to accurately align the pixel area with the element substrate on which thin film transistors are formed, resulting in degradation of image quality, the interlayer film is used as a color filter. The optical layer is directly formed on the element substrate side to more accurately control the formation area, and can correspond to pixels with fine patterns. In addition, since the same insulating layer is used as the interlayer film and the color filter layer, the manufacturing process is simplified and the liquid crystal display device can be manufactured at a lower cost.
Color refers to colors other than achromatic colors such as black, gray, and white. Since the colored layer is used as a color filter, it is formed using a material that transmits only colored colored light. As for the color, red, green, blue, etc. can be used. In addition, cyan, magenta, yellow, etc. can also be used. Transmitting only colored colored light means that the light transmitted in the colored layer has a peak in the wavelength of the colored light.
As the color light-transmitting resin layer 204, because it is used as a colored layer (color Color filter), so it is possible to appropriately control the most suitable thickness by considering the relationship between the concentration of the coloring material contained and the light transmittance. When a stack of a plurality of thin films is used as the interlayer film 209, as long as at least one layer is a colored light-transmitting resin layer, it can be used as a color filter.
When the thickness of the color light-transmitting resin layer is different according to the color of the color, or there are surface irregularities caused by the light-shielding layer or thin-film transistor, a layer capable of transmitting light of the wavelength of the visible light region (that is, so-called colorless and transparent) can be laminated The insulating layer flattens the surface of the interlayer film. By improving the flatness of the interlayer film, the coverage of the pixel electrode layer and the common electrode layer formed thereon is improved, and the gap (thickness) of the liquid crystal layer can be made uniform, thereby further improving the visibility of the liquid crystal display device. Realize high image quality.
As a film capable of attenuating the light intensity of visible light transmitted therethrough, a colored layer serving as a light shielding layer can be used. In the liquid crystal display device of FIG. 2, the interlayer film 209 includes a color light-transmitting resin layer 204 and a light-shielding layer 205, and the light-shielding layer 205 is used as a film provided on the semiconductor layer 223 and capable of reducing the light intensity of visible light transmitted therethrough. . The visible light transmittance of the light shielding layer 205 is lower than the visible light transmittance of the semiconductor layer 223 of the oxide semiconductor layer.
In the mode of the liquid crystal display device of FIG. 2, a plurality of pixels are arranged in a matrix, and the pixels include: a thin film transistor including an oxide semiconductor layer; an interlayer film including a light-shielding layer and a color light-transmitting resin layer; and a pixel electrode And the liquid crystal layer above the pixel electrode layer, wherein, in the interlayer film, a light shielding layer is provided on the thin film transistor, and on the color light-transmitting resin layer Set up the pixel electrode layer.
As the color light-transmitting resin layer 204, light-transmitting organic resins, color pigments, dyes can be used, and pigments, dyes, and the like can also be mixed and used in organic resins. As the light-transmitting organic resin, photosensitive or non-photosensitive resins can be used.
There are no particular restrictions on the method of forming the color light-transmitting resin layer 204, and wet methods such as spin coating, dipping, spraying, droplet spraying (inkjet, screen printing, offset printing, etc.) can be used according to the material. Method, and according to need by etching method (dry etching or wet etching) processing into the desired shape.
When the light-shielding layer 205 (black matrix) is used as the interlayer film 209 disposed on the thin-film transistor 220, the light-shielding layer 205 can block the incidence of light to the semiconductor layer 223 of the thin-film transistor 220, thereby preventing the oxide The change in the electrical characteristics of the thin film transistor 220 caused by the sensitivity of the semiconductor stabilizes it. In addition, since the light shielding layer 205 can also prevent light leakage to adjacent pixels, higher contrast and high-definition display can be performed. Therefore, high definition and high reliability of the liquid crystal display device can be realized.
It is also possible to form a light-shielding layer on the counter substrate side of the liquid crystal display device. It can further improve the contrast or improve the stability of the thin film transistor. When the light-shielding layer is formed on the opposite substrate side, it is formed on the area corresponding to the thin film transistor (at least the area overlapping with the semiconductor layer of the thin film transistor) via the liquid crystal layer, which can further prevent Changes in the electrical characteristics of the thin-film transistors caused by light incident on the substrate.
When a light-shielding layer is formed on the opposite substrate side, the semiconductor layer of the thin-film transistor may block the light from the element substrate and the light from the opposite substrate through the light-shielding wiring layer or electrode layer. It is necessary to form a light-shielding layer to cover the thin film transistor.
The light-shielding layer 205 uses a material that reflects or absorbs light and has light-shielding properties. For example, a black organic resin can be used, and a pigment-based black resin, carbon black, titanium black, etc. may be mixed with a photosensitive or non-photosensitive polyimide resin material. In addition, a light-shielding metal film can also be used. For example, chromium, molybdenum, nickel, titanium, cobalt, copper, tungsten, or aluminum can be used.
There are no particular restrictions on the method of forming the light shielding layer 205. Dry methods such as vapor deposition, sputtering, CVD, etc., or spin coating, dipping, spraying, droplet spraying methods (inkjet It can be processed into a desired shape by etching (dry etching or wet etching) as required by wet methods such as screen printing, offset printing, etc.).
In this specification, it is preferable to use InMO as an oxide semiconductor<sub>3</sub>(ZnO)<sub>m</sub>(m>0) represents the film. In the thin film transistor 220, InMO is formed<sub>3</sub>(ZnO)<sub>m</sub>The thin film represented by (m>0) is used as the semiconductor layer 223. In addition, M represents one metal element or multiple metal elements selected from gallium (Ga), iron (Fe), nickel (Ni), manganese (Mn), aluminum (Al), and cobalt (Co). For example, in addition to the case where Ga is included as M, there are cases where the above-mentioned metal elements other than Ga, such as Ga and Ni or Ga and Fe, are included as M. In addition, in the above-mentioned oxide semiconductor, in addition to the metal element as M, it may also include Contains Fe, Ni and other transition metals or oxides of the transition metals as impurity elements. For example, an In-Ga-Zn-O-based non-single crystal film can be used as the oxide semiconductor layer. However, the semiconductor layer 223 is not limited to InMO<sub>3</sub>(ZnO)<sub>m</sub>The oxide semiconductor layer of the structure represented by (m>0) may contain at least one of indium, gallium, zinc, and tin. For example, zinc oxide (ZnO), tin oxide (SnO), indium zinc oxide (IZO), indium tin oxide (ITO), indium tin oxide (ITSO) containing silicon oxide, indium zinc oxide containing silicon oxide, An oxide semiconductor layer made of gallium-added zinc oxide (GZO) or the like.
In InMO<sub>3</sub>(ZnO)<sub>m</sub>In the (m>0) film (layer), when M is gallium (Ga), the film is also referred to as an In-Ga-Zn-O non-single crystal film in this specification. As the crystalline structure of the In-Ga-Zn-O-based non-single crystal film, even after the film is formed by sputtering, the temperature is 200 degrees to 500 degrees, typically 300 degrees to 400 degrees for 10 minutes to 100 minutes After heat treatment, an amorphous structure was also observed in XRD (X-ray diffraction) analysis. In addition, thin film transistors with the following electrical characteristics can be manufactured: the gate voltage is ±20V, and the on/off ratio is 10<sup>9</sup>Above, and the mobility is 10 or more. In addition, use In<sub>2</sub>O<sub>3</sub>: Ga<sub>2</sub>O<sub>3</sub>: ZnO=1:1:1: The In-Ga-Zn-O non-single crystal film formed by the sputtering method has sensitivity to light with a wavelength of 450 nm or less.
In addition, there is no particular limitation on the structure of the thin film transistor formed in the liquid crystal display device. The thin film transistor may use a single gate structure in which one channel formation region is formed, a double gate structure in which two channel formation regions are formed, or a triple gate structure in which three channel formation regions are formed. in addition, The transistors in the peripheral driving circuit area may also have a single-gate structure, a double-gate structure, or a triple-gate structure.
Thin film transistors can be applied to top gate type (e.g., positive staggered type, coplanar type), bottom gate type (e.g., reverse staggered type, anti-coplanar type), and have gate insulating films that are arranged above and below the channel area. Double gate type or other structure with two gate electrode layers.
In addition, although not shown in FIGS. 1 and 2, optical films such as alignment films, polarizing plates, phase difference plates, anti-reflection films, and the like are appropriately provided. For example, circular polarization using polarizing plates and retardation plates can also be used. In addition, a backlight, a side light, or the like can also be used as a light source.
In addition, a light-shielding layer may be laminated on or under the color light-transmitting resin layer. 17A and 17B show a laminated structure of a light-shielding layer and a color light-transmitting resin layer. In FIGS. 17A and 17B, an element layer 203 is formed on the first substrate 200 of the element substrate, and an interlayer film 209 is formed on the element layer 203. The interlayer film 209 includes color light-transmitting resin layers 204a, 204b, 204c and light-shielding layers 205a, 205b, 205c, 205d, wherein light-shielding layers 205a, 205b, 205c are formed between the color light-transmitting resin layers 204a, 204b, and 204c, respectively And 205d. In addition, the included pixel electrode layer and common electrode layer are omitted in FIGS. 17A and 17B.
A variety of colors can be used for color. For example, in the liquid crystal display device of FIGS. 17A and 17B, the color light-transmitting resin layer 204a is set to red, the color light-transmitting resin layer 204b is set to green, and the color light-transmitting resin layer 204c is set to blue. For the colored coloring layer, a multi-colored colored light-transmitting resin layer is used.
In FIGS. 17A and 17B, a film thinner than the color light-transmitting resin layer is used as the light-shielding layer, and the light-shielding layer is laminated above or below the color light-transmitting resin layer. As such a light-shielding layer, a thin film of a light-shielding inorganic film (for example, a metal film) is preferably used.
In FIG. 17A, thin-film light-shielding layers 205a, 205b, 205c, and 205d are formed on the element layer 203, and color light-transmitting resin layers 204a, 204b, and 204c are laminated on the light-shielding layers 205a, 205b, 205c, and 205d. In addition, in FIG. 17B, color light-transmitting resin layers 204a, 204b, 204c are formed on the element layer 203, and thin-film light-shielding layers 205a, 205b, 205c are laminated on the color light-transmitting resin layers 204a, 204b, 204c. 205d, and an insulating film 211 serving as an overcoat film is formed on the light shielding layers 205a, 205b, 205c, and 205d. As its structure, as shown in FIG. 17B, the element layer, the light-shielding layer, and the color light-transmitting resin layer may be directly laminated, or an insulating film may be provided on the upper surface, the lower surface of these layers, or between them.
As the liquid crystal material of the liquid crystal layer 208, various liquid crystals can be used, and lyotropic liquid crystals, thermotropic liquid crystals, low molecular liquid crystals, polymer liquid crystals, discotic liquid crystals, ferroelectric liquid crystals, antiferroelectric liquid crystals, etc. are appropriately selected for use. That's it.
As the sealing materials 202a and 202b, it is generally preferable to use a visible light curable resin, an ultraviolet curable resin, or a thermosetting resin. Typically, acrylic resin, epoxy resin, amine resin, or the like can be used. In addition, it may also contain photopolymerization initiators, thermosetting agents, fillers, Coupling agent.
In this specification, when the liquid crystal display device is a transmissive liquid crystal display device (or a semi-transmissive liquid crystal display device) that performs display by transmitting light from a light source, it is necessary to transmit light at least in the pixel area. Therefore, the first substrate, the second substrate, and the pixel electrode layer, common electrode layer, other insulating film, conductive film, and other thin films included in the light-transmissive pixel region all have a resistance to light in the wavelength region of visible light. Transparency.
Glass substrates such as barium borosilicate glass or aluminum borosilicate glass, or quartz substrates, plastic substrates, etc. can be used as the first substrate 200 and the second substrate 201. In a liquid crystal display device having a thin film transistor using an oxide semiconductor layer as a channel, at least the interlayer film covering the oxide semiconductor layer is formed with a material capable of reducing the light intensity of visible light transmitted therethrough. In the case of affecting the aperture ratio, the operating characteristics of the thin film transistor are stabilized. Therefore, the reliability of the liquid crystal display device having the thin film transistor can be improved.
Example Mode 2
The liquid crystal display device will be described with reference to FIGS. 18A and 18B.
FIG. 18A shows a plan view of the liquid crystal display device, which represents one pixel. Fig. 18B is a cross-sectional view taken along line X1-X2 of Fig. 18A.
In FIG. 18A, a plurality of source wiring layers (including the wiring layer 405a) are arranged in a state of being parallel to each other (extending in the vertical direction in the figure) and separated from each other. The plurality of gate wiring layers (including the gate electrode layer 401) are arranged in a direction substantially orthogonal to the source electrode wiring layer (in the figure, horizontal It extends in the direction) and is arranged to be separated from each other. The common wiring layer 408 is arranged at a position adjacent to each of the plurality of gate wiring layers and in a direction substantially parallel to the gate wiring layer, that is, a direction substantially orthogonal to the source electrode wiring layer (in the figure, The horizontal direction) extends upward. A substantially rectangular space is surrounded by the source electrode wiring layer, the common wiring layer 408, and the gate wiring layer, and the pixel electrode layer and the common wiring layer of the liquid crystal display device are arranged in this space. The thin film transistor 420 driving the pixel electrode layer is arranged in the upper left corner of the figure. The plurality of pixel electrode layers and the thin film electrocrystalline system are arranged in a matrix.
In the liquid crystal display device of FIGS. 18A and 18B, the first electrode layer 447 electrically connected to the thin film transistor 420 serves as a pixel electrode layer, and the second electrode layer 446 electrically connected to the common wiring layer 408 serves as a common electrode layer. In addition, a capacitor is formed by the first electrode layer and the common wiring layer. Although the common electrode layer can be operated in a floating state (electrically isolated state), it can also be set to a fixed potential. ) Level.
A method of controlling the gray scale by moving liquid crystal molecules in a plane parallel to the substrate by generating an electric field substantially parallel to the substrate (that is, in the lateral direction) can be adopted. As this method, the electrode structure using the IPS mode shown in FIGS. 18A and 18B can be applied.
As a lateral electric field mode such as the IPS mode shown, a first electrode layer having an opening pattern (for example, a pixel electrode layer whose voltage is controlled according to each pixel) and a second electrode layer (for example, The common voltage is supplied to the common electrode layer of all pixels). Therefore, in the first A first electrode layer 447 and a second electrode layer 446 are formed on a substrate 441, one of which is a pixel electrode layer and the other is a common electrode layer, and at least one of the first electrode layer and the second electrode layer is Formed on the interlayer film. The first electrode layer 447 and the second electrode layer 446 are not planar, but have various opening patterns, including curved portions or bifurcated comb teeth. Since the first electrode layer 447 and the second electrode layer 446 generate an electric field between the electrode layers, they are arranged in the same shape and do not overlap each other.
The liquid crystal is controlled by applying an electric field between the pixel electrode layer and the common electrode layer. Since the electric field in the lateral direction is applied to the liquid crystal, the electric field can be used to control the liquid crystal molecules. That is, since the liquid crystal molecules aligned parallel to the substrate can be controlled in a direction parallel to the substrate, the viewing angle can be enlarged.
8A to 8D show other examples of the first electrode layer 447 and the second electrode layer 446. As shown in the top views of FIGS. 8A to 8D, the first electrode layers 447a to 447d and the second electrode layers 446a to 446d are alternately formed. In FIG. 8A, the first electrode layer 447a and the second electrode layer 446a are undulating waves. In Fig. 8B, the first electrode layer 447b and the second electrode layer 446b have concentric openings. In Fig. 8C, the first electrode layer 447c and the second electrode layer 446c are comb-shaped and partly The shape is stacked on each other. In FIG. 8D, the first electrode layer 447d and the second electrode layer 446d have a comb tooth shape and the electrodes have a shape in which they mesh with each other. In addition, as shown in FIGS. 8A to 8C, when the first electrode layers 447a, 447b, and 447c overlap the second electrode layers 446a, 446b, and 446c, an insulating film is formed between the first electrode layer 447 and the second electrode layer 446. , And shape on different membranes A first electrode layer 447 and a second electrode layer 446 are formed.
The thin film transistor 420 is an inverted staggered thin film transistor, and on the first substrate 441 of the substrate with an insulating surface, it includes: a gate electrode layer 401, a gate insulating layer 402, a semiconductor layer 403, serving as a source region or N in the drain region<sup>+</sup>The layers 404a, 404b, and the wiring layers 405a, 405b serving as source electrode layers or drain electrode layers.
An insulating film 407 in contact with the semiconductor layer 403 is provided to cover the thin film transistor 420. An interlayer film 413 is provided on the insulating film 407, and a first electrode layer 447 and a second electrode layer 446 are formed on the interlayer film 413.
In the liquid crystal display device of FIGS. 18A and 18B, a color light-transmitting resin layer 417, which is a film capable of reducing the light intensity of visible light transmitted therethrough, is used as the interlayer film 413.
When the colored layer of the color light-transmitting resin layer 417 is used as the interlayer film 413 provided on the thin film transistor 420, the semiconductor layer 403 incident on the thin film transistor 420 can be weakened without reducing the aperture ratio of the pixel. The intensity of the light can thereby prevent the change in the electrical characteristics of the thin film transistor 420 due to the sensitivity of the oxide semiconductor and stabilize it. In addition, the color light-transmitting resin layer 417 can also be used as a color filter layer. When a color filter layer is provided on the opposite substrate side, although there is a concern that it is difficult to accurately align the pixel area with the element substrate on which thin film transistors are formed, resulting in degradation of image quality, the interlayer film is used as a color filter. The optical layer is directly formed on the element substrate side to more accurately control the formation area, and can correspond to pixels with fine patterns. In addition, due to the use of the same insulating layer and As an interlayer film and a color filter layer, the manufacturing process is simplified and the liquid crystal display device can be manufactured at a lower cost.
As the color translucent resin, photosensitive or non-photosensitive organic resins can be used. When a photosensitive organic resin layer is used, the number of resist masks can be reduced, thereby simplifying the manufacturing process, so it is preferable. In addition, since the contact hole formed in the interlayer film also has an opening shape having a curvature, the coverage of the film such as the electrode layer formed in the contact hole can also be improved.
The method for forming the interlayer film 413 (color light-transmitting resin layer 417) is not particularly limited, and spin coating, dipping, spraying, droplet jetting methods (inkjet, screen printing, offset printing, etc.) can be used according to the material. , Doctor blade, roller coater, curtain coater, knife coater, etc. to form.
A liquid crystal layer 444 is disposed on the first electrode layer 447 and the second electrode layer 446, and the liquid crystal layer 444 is sealed by the second substrate 442 of the opposite substrate.
The first substrate 441 and the second substrate 442 are light-transmitting substrates, and polarizing plates 443a and 443b are respectively provided on their outer sides (sides opposite to the liquid crystal layer 444).
As the first electrode layer 447 and the second electrode layer 446, a light-transmitting conductive material such as indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, and oxide containing titanium oxide can be used. Indium tin, indium tin oxide (hereinafter referred to as ITO), indium zinc oxide, indium tin oxide added with silicon oxide, and the like.
In addition, a conductive composition containing a conductive polymer (also referred to as a conductive polymer) can be used to form the first electrode layer 447 and the second electrode layer. 446. The sheet resistance of the pixel electrode formed using the conductive composition is preferably 10000 Ω/ or less, and the light transmittance at a wavelength of 550 nm is preferably 70% or more. In addition, the resistivity of the conductive polymer contained in the conductive composition is preferably 0.1Ω. cm below.
As the conductive polymer, a so-called π-electron conjugated conductive polymer can be used. For example, polyaniline or a derivative thereof, polypyrrole or a derivative thereof, polythiophene or a derivative thereof, or a copolymer of two or more of the above-mentioned materials, and the like can be mentioned.
It is also possible to provide an insulating film as a base film between the first substrate 441 and the gate electrode layer 401. The base film has the function of preventing the diffusion of impurities from the first substrate 441, and may be a stack of one or more films selected from a silicon nitride film, a silicon oxide film, a silicon oxynitride film, or a silicon oxynitride film. Structure to form. The gate electrode layer 401 can be formed by using a single layer or a stack of metal materials such as molybdenum, titanium, chromium, tantalum, tungsten, aluminum, copper, neodymium, scandium, or an alloy material containing these as main components. When a conductive film having light-shielding properties is used as the gate electrode layer 401, light from the backlight (light incident from the first substrate 441) can be prevented from entering the semiconductor layer 403.
For example, as the two-layer structure of the gate electrode layer 401, it is preferable to adopt: a two-layer structure in which a molybdenum layer is laminated on an aluminum layer; a two-layer structure in which a molybdenum layer is laminated on a copper layer; A two-layer structure with a titanium nitride layer or a tantalum nitride layer laminated thereon; or a two-layer structure with a titanium nitride layer and a molybdenum layer laminated. As a three-layer laminated structure, the following laminated layers are preferably used: a tungsten layer or a tungsten nitride layer, an alloy of aluminum and silicon or an alloy of aluminum and titanium, and a titanium nitride layer or a titanium layer.
The gate insulating layer 402 can be formed by using a single layer or a stack of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, or a silicon oxynitride layer using a CVD method, a sputtering method, or the like. In addition, as the gate insulating layer 402, a silicon oxide layer can also be formed by a CVD method using organosilane gas. As the organosilane gas, a compound containing silicon can be used, such as tetraethoxysilane (TEOS: chemical formula is Si(OC<sub>2</sub>H<sub>5</sub>)<sub>4</sub>), tetramethylsilane (TMS: chemical formula is Si(CH<sub>3</sub>)<sub>4</sub>), tetramethylcyclotetrasiloxane (TMCTS), octamethylcyclotetrasiloxane (OMCTS), hexamethyldisilazane (HMDS), triethoxysilane (SiH(OC<sub>2</sub>H<sub>5</sub>)<sub>3</sub>), tris(dimethylamino)silane (SiH(N(CH<sub>3</sub>)<sub>2</sub>)<sub>3</sub>)Wait.
It is preferable to perform reverse sputtering in which argon gas is introduced to generate plasma before forming the oxide semiconductor film used as the semiconductor layer 403 to remove dust adhering to the surface of the gate insulating layer. In addition, nitrogen, helium, etc. can also be used instead of the argon atmosphere. In addition, oxygen, hydrogen, and N can be added to the argon atmosphere.<sub>2</sub>Under the atmosphere of O etc. In addition, you can also add Cl in the argon atmosphere<sub>2</sub>, CF<sub>4</sub>Under the atmosphere of waiting.
As the n used as the semiconductor layer 403 and the source region or the drain region<sup>+</sup>For the layers 404a and 404b, In-Ga-Zn-O non-single crystal films can be used. n<sup>+</sup>The layers 404a and 404b are oxide semiconductor layers with lower resistance than the semiconductor layer 403. For example, n<sup>+</sup>The layers 404a and 404b have n-type conductivity, and the activation energy (ΔE) is 0.01 eV or more and 0.1 eV or less. n<sup>+</sup>The layers 404a and 404b are In-Ga-Zn-O-based non-single crystal films, which contain at least an amorphous component. n<sup>+</sup>The layers 404a and 404b sometimes contain crystal grains (nanocrystals) in an amorphous structure. The n<sup>+</sup>The crystal grains (nanocrystals) in the layers 404a, 404b have a diameter of 1 nm to 10 nm, and typically about 2 nm to 4 nm.
By setting n<sup>+</sup>The layers 404a and 404b enable good bonding between the wiring layers 405a and 405b of the metal layer and the semiconductor layer 403 of the oxide semiconductor layer, and can also have a stable operation in terms of heat compared with the Schottky junction. In addition, in order to supply carriers of the channel (on the source electrode side), stably absorb the carriers of the channel (on the drain electrode side), or not generate resistance components at the interface with the wiring layer, positively set n<sup>+</sup>The layer is effective. In addition, by reducing resistance, good mobility can be maintained even at high drain electrode voltages.
The deposition conditions of the first In-Ga-Zn-O non-single-crystal film used as the semiconductor layer 403 are the same as those used as the n<sup>+</sup>The deposition conditions of the second In-Ga-Zn-O-based non-single crystal film of the layers 404a and 404b are different. For example, the following condition is adopted: Compared with the ratio of the oxygen gas flow rate and the argon gas flow rate in the deposition conditions of the second In-Ga-Zn-O based non-single crystal film, the first In-Ga-Zn-O based non-single crystal film The ratio of the oxygen gas flow rate in the deposition conditions of the crystal film is more. Specifically, the deposition conditions of the second In-Ga-Zn-O-based non-single crystal film are set to a rare gas (argon or helium, etc.) atmosphere (or oxygen gas is 10% or less, argon gas is 90% or more) , And set the deposition condition of the first In-Ga-Zn-O-based non-single crystal film to be in an oxygen atmosphere (or the flow rate of the oxygen gas is equal to or greater than the flow rate of the argon gas).
For example, the first In-Ga-Zn-O-based non-single crystal film used as the semiconductor layer 403 uses an oxide semiconductor target containing In, Ga, and Zn with a diameter of 8 feet (In<sub>2</sub>O<sub>3</sub>: Ga<sub>2</sub>O<sub>3</sub>: ZnO=1:1:1:1), and the substrate The distance to the target is set to 170 mm, the pressure is 0.4 Pa, the direct current (DC) power source is 0.5 kW, and it is formed in an argon or oxygen atmosphere. In addition, the use of pulsed direct current (DC) power can reduce dust and make the thickness distribution of the film uniform, so it is preferable. The thickness of the first In-Ga-Zn-O-based non-single crystal film is set to 5 nm to 200 nm.
On the other hand, used as n<sup>+</sup>The second oxide semiconductor film of the layers 404a, 404b uses In<sub>2</sub>O<sub>3</sub>: Ga<sub>2</sub>O<sub>3</sub>: ZnO=1:1:1:1 target material, and formed by sputtering method under the following deposition conditions: pressure 0.4Pa; power is 500W; deposition temperature is room temperature; the introduced argon gas flow rate is 40sccm. In some cases, an In-Ga-Zn-O-based non-single crystal film including crystal grains having a size of 1 nm to 10 nm is formed immediately after the film is formed. In addition, you can appropriately adjust the target composition ratio, deposition pressure (0.1Pa to 2.0Pa), power (250W to 3000W: 8 inches Φ), temperature (room temperature to 100 degrees), reactive sputtering deposition Conditions etc., the presence or absence of crystal grains and the density of crystal grains can be adjusted, and the diameter size of the crystal grains can also be adjusted within the range of 1 nm to 10 nm. The thickness of the second In-Ga-Zn-O-based non-single crystal film is 5 nm to 20 nm. Of course, when crystal grains are included in the film, the size of the crystal grains included does not exceed the thickness of the film. The thickness of the second In-Ga-Zn-O-based non-single crystal film is set to 5 nm.
The sputtering method includes an RF sputtering method using a high-frequency power source as a sputtering power source, a DC sputtering method, and a pulsed DC sputtering method in which a bias voltage is applied in a pulsed manner. The RF sputtering method is mainly used to form an insulating film, and the DC sputtering method is mainly used to form a metal film.
In addition, there is also a multi-source sputtering that can set multiple targets with different materials Device. The multi-source sputtering device can not only laminate and form films of different materials in the same reaction chamber, but also discharge multiple materials simultaneously in the same reaction chamber to form films.
In addition, there are also sputtering devices using the magnetron sputtering method and sputtering devices using the ECR sputtering method. In the sputtering device using the magnetron sputtering method, a magnet mechanism is provided inside the reaction chamber, while in the sputtering device using the ECR sputtering method, plasma generated using microwaves is used instead of glow discharge.
In addition, as a deposition method using a sputtering method, there are a reactive sputtering method and a bias sputtering method. In the reactive sputtering method, the target material and the sputtering gas components are chemically reacted during deposition to form a thin film of these compounds, while in the bias sputtering method, a voltage is also applied to the substrate when the film is formed .
In the semiconductor layer, n<sup>+</sup>In the manufacturing process of layers and wiring layers, an etching process is used to process the thin film into the desired shape. As the etching process, dry etching or wet etching can be used.
As the etching gas used in dry etching, a gas containing chlorine (chlorine-based gas, such as chlorine (Cl<sub>2</sub>), boron chloride (BCl<sub>3</sub>), silicon chloride (SiCl<sub>4</sub>), carbon tetrachloride (CCl<sub>4</sub>)Wait).
In addition, a gas containing fluorine (fluorine-based gas, such as carbon tetrafluoride (CF<sub>4</sub>), sulfur hexafluoride (SF<sub>6</sub>), nitrogen trifluoride (NF<sub>3</sub>), trifluoromethane (CHF<sub>3</sub>), etc.), hydrogen bromide (HBr), oxygen (O<sub>2</sub>), or a gas in which a rare gas such as helium (He) or argon (Ar) is added to the above gas.
As an etching equipment for dry etching, reactive Ion etching (RIE) etching equipment, dry etching equipment using high-density plasma sources such as ECR (Electron Cyclotron Resonance) or ICP (Inductively Coupled Plasma). In addition, as a dry etching device that is easier to obtain uniform discharge over a wider area than an ICP etching device, an ECCP (enhanced capacitively coupled plasma) mode etching device can be cited. In this etching device, Ground the upper electrode, connect a 13.56 MHz high-frequency power source to the lower electrode, and connect a 3.2 MHz low-frequency power source to the lower electrode. If the etching equipment of the ECCP mode is adopted, for example, a tenth-generation substrate with a size exceeding 3 m can be used as a substrate.
The etching conditions (the amount of electric power applied to the coil-shaped electrode, the amount of electric power applied to the electrode on the substrate side, the temperature of the electrode on the substrate side, etc.) are appropriately controlled to etch into a desired processing shape.
As an etching solution used for wet etching, a solution mixed with phosphoric acid, acetic acid, and nitric acid, hydrogen peroxide ammonia water (hydrogen peroxide: ammonia: water = 5: 2: 2), etc. can be used. In addition, ITO-07N (manufactured by Kanto Chemical Co., Ltd.) can also be used.
In addition, the etching solution after wet etching is removed by cleaning together with the material to be etched. It is also possible to purify the waste liquid of the etching solution containing the removed material and reuse the contained material. By recovering and reusing materials such as indium contained in the oxide semiconductor layer from the waste liquid after etching, it is possible to effectively utilize resources and achieve cost reduction.
The etching conditions (etching liquid, etching time, temperature, etc.) are appropriately controlled according to the material to be etched into a desired processing shape.
Examples of the material of the wiring layers 405a and 405b include an element selected from Al, Cr, Ta, Ti, Mo, and W, an alloy containing the above-mentioned elements, and an alloy film in which the above-mentioned elements are combined. In addition, in the case of performing a heat treatment of 200 degrees to 600 degrees, it is preferable that the conductive film has heat resistance to withstand the heat treatment. When only Al is used, the heat resistance is very low and there are problems such as easy corrosion, so it is formed by combining Al with a heat-resistant conductive material. As a heat-resistant conductive material combined with Al, an element selected from titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (Mo), chromium (Cr), neodymium (Nd), scandium (Sc), An alloy containing the aforementioned elements as a component, an alloy film combining the aforementioned elements, or a nitride containing the aforementioned elements as a component.
It is possible to continuously form the gate insulating layer 402, the semiconductor layer 403, and n without contacting the atmosphere.<sup>+</sup>Layers 404a, 404b and wiring layers 405a, 405b. By continuously performing film formation without contacting the atmosphere, each layered interface can be formed without being polluted by atmospheric components or pollutant impurity elements suspended in the atmosphere. Therefore, the variation in the characteristics of the thin film transistor can be reduced.
In addition, the semiconductor layer 403 is only partially etched, and has grooves (recesses).
For the semiconductor layer 403, n<sup>+</sup>The layers 404a and 404b can be heat-treated at a temperature of 200 degrees to 600 degrees, typically 300 degrees to 500 degrees. For example, heat treatment is performed at 350 degrees for one hour in a nitrogen atmosphere. By this heat treatment, the formation of the semiconductor layer 403 and n<sup>+</sup>The layers 404a and 404b are rearranged at the atomic level of the In-Ga-Zn-O-based oxide semiconductor. This heat treatment (including light annealing, etc.) can prevent the semiconductor layer 403, n<sup>+</sup>Strain release of the migration of carriers in layers 404a, 404b This is very important. In addition, as for the timing of the above-mentioned heat treatment, as long as the semiconductor layer 403 and n<sup>+</sup>After the layers 404a and 404b, there is no particular limitation.
In addition, the exposed recesses of the semiconductor layer 403 may be treated with oxygen radicals. Free radical treatment is better at O<sub>2</sub>, N<sub>2</sub>O, N containing oxygen<sub>2</sub>, In an atmosphere of He containing oxygen, Ar containing oxygen, etc. In addition, Cl can be added to the above atmosphere<sub>2</sub>, CF<sub>4</sub>Under the atmosphere. In addition, it is preferable to perform radical treatment without applying a bias to the first substrate 441 side.
The insulating film 407 covering the thin film transistor 420 may use an inorganic insulating film or an organic insulating film formed by a dry method or a wet method. For example, a silicon nitride film, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, a tantalum oxide film, etc. formed by a CVD method, a sputtering method, or the like can be used. In addition, organic materials such as acrylic resin, polyimide, benzocyclobutene, polyamide, or epoxy resin can be used. In addition, in addition to the above-mentioned organic materials, low dielectric constant materials (low-k materials), silicone resins, PSG (phosphosilicate glass), BPSG (borophosphosilicate glass), etc. can also be used.
In addition, the silicone-based resin is equivalent to a resin containing Si-O-Si bonds formed from a silicone-based material as a starting material. The silicone resin may also use an organic group (for example, an alkyl group or an aryl group) or a fluorine group as a substituent. In addition, the organic group may also include a fluorine group. A film of silicone-based resin is formed by a coating method, and is used as the insulating film 407 by firing it.
In addition, the insulating film 407 can also be formed by stacking a plurality of insulating films formed of these materials. For example, it can also be used on an inorganic insulating film The structure of the laminated organic resin film.
In addition, by using a multi-tone (multi-tone) mask to form a resist mask with multiple (typically two) thickness regions, the number of resist masks can be reduced, and the manufacturing process can be achieved. Simplification and low cost.
By improving the contrast or viewing angle characteristics, a liquid crystal display device with higher image quality can be provided. In addition, the liquid crystal display device can be manufactured at lower cost and with high productivity.
In addition, the characteristics of the thin film transistor can be stabilized, and the reliability of the liquid crystal display device can be improved.
Example Mode 3
In Embodiment Mode 3, FIGS. 3A and 3B, FIGS. 4A and 4B, and FIGS. 7A and 7B show examples in which the pixel electrode layer and the common electrode layer are formed on different planes. In addition, the same materials and manufacturing methods can be used for the same parts as in Embodiment Mode 1 and Embodiment Mode 2, and detailed descriptions of the same parts or parts having the same functions are omitted.
3A, 4A, and 7A are plan views of the liquid crystal display device and show one pixel. 3B, 4B, and 7B are cross-sectional views taken along the line X1-X2 of FIGS. 3A, 4A, and 7A.
In the plan views of FIGS. 3A, 4A, and 7A, similar to Embodiment Mode 2, a plurality of source electrode wiring layers (including the wiring layer 405a) are parallel to each other (in the figure, extending in the vertical direction) and The state of leaving each other to be configured. Multiple gate wiring layers (including gate electrode layer 401) It extends in a direction (horizontal direction in the figure) substantially orthogonal to the source electrode wiring layer and is arranged to be separated from each other. The common wiring layer 408 is arranged at a position adjacent to each of the plurality of gate wiring layers and in a direction substantially parallel to the gate wiring layer, that is, a direction substantially orthogonal to the source electrode wiring layer (Figure In the horizontal direction). A substantially rectangular space is surrounded by the source electrode wiring layer, the common wiring layer 408, and the gate wiring layer, and the pixel electrode layer and the common wiring layer of the liquid crystal display device are arranged in this space. The thin film transistor 420 driving the pixel electrode layer is arranged in the upper left corner of the figure. The multiple pixel electrode layers and the thin film electrocrystalline system are arranged in a matrix.
In the liquid crystal display devices of FIGS. 3A and 3B, FIGS. 4A and 4B, and FIGS. 7A and 7B, as shown in the cross-sectional views of FIGS. 3B, 4B, and 7B, the first electrode layer 447 of the pixel electrode layer and the common electrode layer The second electrode layers 446 are respectively provided on different films (different layers). Although FIGS. 3B, 4B, and 7B show an example in which the first electrode layer 447 of the pixel electrode layer is formed under the second electrode layer 446 of the common electrode layer with an insulating film interposed therebetween, a common electrode layer may also be used. The second electrode layer 446 of the pixel electrode layer is formed under the first electrode layer 447 of the pixel electrode layer with an insulating film interposed therebetween.
In the liquid crystal display devices of FIGS. 3A, 4A, and 7A, the first electrode layer 447 electrically connected to the thin film transistor 420 serves as a pixel electrode layer, and the second electrode layer 446 electrically connected to the common wiring layer 408 serves as Common electrode layer.
In FIGS. 3A and 3B, a first electrode layer 447 is formed on the first substrate 441, and a gate insulating layer is laminated on the first electrode layer 447 402, a wiring layer 405b, an insulating film 407, and an interlayer film 413, and a second electrode layer 446 is formed on the interlayer film 413. In addition, in FIGS. 3A and 3B, the wiring layer 410 and the first electrode layer 447 formed by the same process as the wiring layers 405a and 405b form a capacitor.
In FIGS. 4A and 4B, a first electrode layer 447 is formed on the insulating film 407, an interlayer film 413 is laminated on the first electrode layer 447, and a second electrode layer 446 is formed on the interlayer film 413. . In addition, in FIGS. 4A and 4B, a capacitor is formed by the first electrode layer and the common wiring layer.
In FIGS. 7A and 7B, a first electrode layer 447 is formed on the interlayer film 413, an insulating film 416 is laminated on the first electrode layer 447, and a second electrode layer 446 is formed on the insulating film 416. . In addition, in FIGS. 7A and 7B, a capacitor is formed by the first electrode layer and the common wiring layer. In addition, in FIGS. 7A and 7B, the first electrode layer 447 and the second electrode layer 446 have a comb-tooth shape, and the angle of the bent portion is 90 degrees. In this way, when the angle of the bent portion of the first electrode layer 447 and the second electrode layer 446 is 90 degrees, the difference between the polarization axis of the polarizing plate and the alignment angle of the liquid crystal molecules can be 45 degrees, and the transmittance during white display can be improved. maximum.
When the colored layer of the color light-transmitting resin layer is used as an interlayer film disposed on the thin film transistor, the intensity of light incident on the semiconductor layer of the thin film transistor can be reduced without reducing the aperture ratio of the pixel. Therefore, it can prevent and stabilize the change in the electrical characteristics of the thin film transistor due to the sensitivity of the oxide semiconductor. In addition, the color light-transmitting resin layer can also be used as a color filter layer. When the color filter layer is provided on the opposite substrate side, it is difficult to perform the same with the element substrate on which the thin film transistor is formed. Accurate alignment of the pixel area leads to concerns about image quality degradation. However, by directly forming the interlayer film as a color filter layer on the device substrate side, the formation area can be controlled more accurately, and it can correspond to pixels with fine patterns. In addition, since the same insulating layer is used as the interlayer film and the color filter layer, the manufacturing process is simplified and the liquid crystal display device can be manufactured at a lower cost.
By improving the contrast or viewing angle characteristics, a liquid crystal display device with higher image quality can be provided. In addition, the liquid crystal display device can be manufactured at lower cost and with high productivity.
In addition, the characteristics of the thin film transistor can be stabilized, and the reliability of the liquid crystal display device can be improved.
Embodiment Mode 4
A liquid crystal display device having a light shielding layer (black matrix) will be described with reference to FIGS. 5A and 5B.
The liquid crystal display device shown in FIGS. 5A and 5B is an example in which the light shielding layer 414 is further formed on the second substrate 442 side of the counter substrate in the liquid crystal display device shown in FIGS. 18A and 18B of Embodiment Mode 2. Therefore, the same materials and manufacturing methods can be used for the same parts as in Embodiment Mode 2, and detailed descriptions of the same parts or parts with the same functions are omitted.
5A is a plan view of the liquid crystal display device, and FIG. 5B is a cross-sectional view taken along the line X1-X2 of FIG. 5A. In addition, in the plan view of FIG. 5A, only the element substrate side is shown, and the description of the counter substrate side is omitted.
A light-shielding layer 414 and an insulating layer 415 as a planarizing film are formed on the liquid crystal layer 444 side of the second substrate 442. The light-shielding layer 414 preferably intersects the liquid crystal The layer 444 is formed on a region corresponding to the thin film transistor 420 (a region overlapping with the semiconductor layer of the thin film transistor). The first substrate 441 and the second substrate 442 are fixed so as to sandwich the liquid crystal layer 444 so that the light shielding layer 414 is arranged so as to cover at least the upper side of the semiconductor layer 403 of the thin film transistor 420.
The light-shielding layer 414 uses a material that reflects or absorbs light and has light-shielding properties. For example, a black organic resin can be used, and a pigment-based black resin, carbon black, titanium black, etc. may be mixed with a photosensitive or non-photosensitive polyimide resin material. In addition, a light-shielding metal film can also be used. For example, chromium, molybdenum, nickel, titanium, cobalt, copper, tungsten, or aluminum can be used.
The method for forming the light shielding layer 414 is not particularly limited. Dry methods such as vapor deposition, sputtering, CVD, etc., or spin coating, dipping, spraying, droplet spraying methods (inkjet Method, screen printing, offset printing, etc.), and processed into a desired shape by an etching method (dry etching or wet etching) as needed.
The insulating layer 415 can also be formed by using an organic resin such as acrylic resin or polyimide, etc., and using a coating method such as spin coating or various printing methods.
In this way, by further providing the light shielding layer 414 on the opposite substrate side, the contrast can be further improved and the stability of the thin film transistor can be improved. Since the light shielding layer 414 can block the incidence of light to the semiconductor layer 403 of the thin film transistor 420, it prevents the change in the electrical characteristics of the thin film transistor 420 due to the sensitivity of the oxide semiconductor and makes it more stable. In addition, due to the shading The optical layer 414 can also prevent light leakage to adjacent pixels, so higher contrast and high-definition display can be performed. Therefore, high definition and high reliability of the liquid crystal display device can be realized.
By improving the contrast or viewing angle characteristics, a liquid crystal display device with higher image quality can be provided. In addition, the liquid crystal display device can be manufactured at lower cost and with high productivity.
In addition, the characteristics of the thin film transistor can be stabilized, and the reliability of the liquid crystal display device can be improved.
This embodiment mode can be implemented in appropriate combination with the structures described in the other embodiment modes.
Embodiment Mode 5
A liquid crystal display device having a light shielding layer (black matrix) will be described with reference to FIGS. 6A and 6B.
The liquid crystal display device shown in FIGS. 6A and 6B is an example in which the light shielding layer 414 is formed as a part of the interlayer film 413 on the first substrate 441 side of the element substrate in the liquid crystal display device shown in FIGS. 18A and 18B of Embodiment Mode 2. Therefore, the same materials and manufacturing methods can be used for the same parts as in Embodiment Mode 2, and detailed descriptions of the same parts or parts with the same functions are omitted.
6A is a plan view of the liquid crystal display device, and FIG. 6B is a cross-sectional view taken along the line X1-X2 of FIG. 6A. In addition, only the element substrate side is shown in the plan view of FIG. 6A, and the description of the counter substrate side is omitted.
The interlayer film 413 includes a light-shielding layer 414 and a color light-transmitting resin layer 417. The light shielding layer 414 is provided on the first substrate 441 side of the element substrate, and is formed on the thin film transistor 420 (at least covering the area of the semiconductor layer of the thin film transistor) with the insulating film 407 interposed therebetween, and serves as a semiconductor Layer of shading layer. On the other hand, the color light-transmitting resin layer 417 is formed in a region overlapping the first electrode layer 447 and the second electrode layer 446, and serves as a color filter layer. In the liquid crystal display device of FIG. 6B, a part of the second electrode layer 446 is formed on the light shielding layer 414, and a liquid crystal layer 444 is provided thereon.
Since the light shielding layer 414 is used as an interlayer film, it is preferable to use a black organic resin. For example, it may be formed by mixing a pigment-based black resin, carbon black, titanium black, etc., with a photosensitive or non-photosensitive polyimide or other resin material. As for the method of forming the light-shielding layer 414, a wet method such as spin coating, dipping, spraying, droplet spraying (inkjet, screen printing, offset printing, etc.) can be used according to its material, and by The etching method (dry etching or wet etching) is processed into the desired shape.
In this way, by providing the light-shielding layer 414, the light-shielding layer 414 can block the incidence of light to the semiconductor layer 403 of the thin film transistor 420 without reducing the aperture ratio of the pixel, thereby preventing the light-sensitive effect of the oxide semiconductor. The change in the electrical characteristics of the thin film transistor 420 caused by the temperature makes it more stable. In addition, since the light shielding layer 414 can also prevent light leakage to adjacent pixels, higher contrast and high-definition display can be performed. As a result, high definition and high reliability of the liquid crystal display device can be realized.
In addition, the color light-transmitting resin layer 417 can also be used as a color filter layer. When the color filter layer is provided on the opposite substrate side, although it is difficult to form The element substrate with thin film transistors is accurately aligned to the pixel area, which may cause the image quality to deteriorate. However, the color light-transmitting resin layer 417 included in the interlayer film is directly formed on the element substrate as a color filter layer. The side can more accurately control the formation area, and can correspond to the pixels of the fine pattern. In addition, since the same insulating layer is used as the interlayer film and the color filter layer, the manufacturing process is simplified and the liquid crystal display device can be manufactured at a lower cost.
By improving the contrast or viewing angle characteristics, a liquid crystal display device with higher image quality can be provided. In addition, the liquid crystal display device can be manufactured at lower cost and with high productivity.
In addition, the characteristics of the thin film transistor can be stabilized, and the reliability of the liquid crystal display device can be improved.
This embodiment mode can be implemented in appropriate combination with the structures described in the other embodiment modes.
Embodiment Mode 6
Other examples of thin film transistors that can be used in liquid crystal display devices in Embodiment Mode 1 to Embodiment Mode 5 are shown. In addition, the same materials and manufacturing methods can be used for the same parts as in Embodiment Mode 2 to Embodiment Mode 5, and detailed descriptions of the same parts or parts having the same functions are omitted.
10A and 10B show the source electrode layer and the drain electrode layer and the semiconductor layer so as not to be separated by n<sup>+</sup>An example of a liquid crystal display device with a thin-film transistor structure of layer-wise contact.
FIG. 10A is a plan view of the liquid crystal display device and shows one pixel. picture 10B is a cross-sectional view taken along the line V1-V2 of FIG. 10A.
In the plan view of FIG. 10A, similar to Embodiment Mode 2, a plurality of source electrode wiring layers (including the wiring layer 405a) are parallel to each other (in the figure, extending in the vertical direction) and separated from each other. Configuration. The plurality of gate wiring layers (including the gate electrode layer 401) extend in a direction (horizontal direction in the figure) substantially orthogonal to the source electrode wiring layer and are arranged to be separated from each other. The common wiring layer 408 is arranged at a position adjacent to each of the plurality of gate wiring layers and in a direction substantially parallel to the gate wiring layer, that is, a direction substantially orthogonal to the source electrode wiring layer (in the figure) , The horizontal direction) extends upward. A substantially rectangular space is surrounded by the source electrode wiring layer, the common wiring layer 408, and the gate wiring layer, and the pixel electrode layer and the common wiring layer of the liquid crystal display device are arranged in this space. The thin film transistor 422 driving the pixel electrode layer is arranged in the upper left corner of the figure. The multiple pixel electrode layers and the thin film electrocrystalline system are arranged in a matrix.
The first substrate 441 and the second substrate 442 provided with the thin film transistor 422, the interlayer film 413 of the color light-transmitting resin layer, the first electrode layer 447, and the second electrode layer 446 are provided with a liquid crystal layer 444 sandwiched therebetween. fixed.
The thin film transistor 422 has the following structure: the wiring layers 405a and 405b serving as the source electrode layer and the drain electrode layer and the semiconductor layer 403 are not separated from each other.<sup>+</sup>Layer by layer contact.
When the colored layer of the color light-transmitting resin layer is used as an interlayer film disposed on the thin film transistor, the intensity of light incident on the semiconductor layer of the thin film transistor can be reduced without reducing the aperture ratio of the pixel. So that It plays a role in preventing and stabilizing the change in the electrical characteristics of the thin film transistor due to the sensitivity of the oxide semiconductor. In addition, the color light-transmitting resin layer can also be used as a color filter layer. When a color filter layer is provided on the opposite substrate side, although there is a concern that it is difficult to accurately align the pixel area with the element substrate on which thin film transistors are formed, resulting in degradation of image quality, the interlayer film is used as a color filter. The optical layer is directly formed on the element substrate side to more accurately control the formation area, and can correspond to pixels with fine patterns. In addition, since the same insulating layer is used as the interlayer film and the color filter layer, the manufacturing process is simplified and the liquid crystal display device can be manufactured at a lower cost.
By improving the contrast and viewing angle characteristics to achieve high-speed response, it is possible to provide a liquid crystal display device with higher image quality and high performance. In addition, the liquid crystal display device can be manufactured at lower cost and with high productivity.
In addition, the characteristics of the thin film transistor can be stabilized, and the reliability of the liquid crystal display device can be improved.
This embodiment mode can be implemented in appropriate combination with the structures described in the other embodiment modes.
Embodiment Mode 7
Other examples of thin film transistors that can be used in liquid crystal display devices in Embodiment Mode 1 to Embodiment Mode 5 will be described with reference to FIGS. 9A and 9B.
FIG. 9A is a plan view of the liquid crystal display device and shows one pixel. Fig. 9B is a cross-sectional view taken along the line Z1-Z2 of Fig. 9A.
In the plan view of FIG. 9A, similar to Embodiment Mode 2, a plurality of The source electrode wiring layers (including the wiring layer 405a) are arranged in a state of being parallel to each other (extending in the vertical direction in the figure) and separated from each other. The plurality of gate wiring layers (including the gate electrode layer 401) extend in a direction (horizontal direction in the figure) substantially orthogonal to the source electrode wiring layer and are arranged to be separated from each other. The common wiring layer 408 is arranged at a position adjacent to each of the plurality of gate wiring layers and in a direction substantially parallel to the gate wiring layer, that is, a direction substantially orthogonal to the source electrode wiring layer (in the figure) , The horizontal direction) extends upward. A substantially rectangular space is surrounded by the source electrode wiring layer, the common wiring layer 408, and the gate wiring layer, and the pixel electrode layer and the common wiring layer of the liquid crystal display device are arranged in this space. The thin film transistor 421 driving the pixel electrode layer is arranged in the upper left corner of the figure. The multiple pixel electrode layers and the thin film electrocrystalline system are arranged in a matrix.
The first substrate 441 and the second substrate 442 provided with the thin film transistor 421, the interlayer film 413 of the color light-transmitting resin layer, the first electrode layer 447, and the second electrode layer 446 are provided with a liquid crystal layer 444 sandwiched therebetween. fixed.
The thin film transistor 421 is a bottom gate type thin film transistor, and it includes a gate electrode layer 401, a gate insulating layer 402, used as a source electrode layer or drain on the first substrate 441 of a substrate with an insulating surface. Wiring layers 405a, 405b of the electrode layer, n used as a source region or a drain region<sup>+</sup>Layers 404a, 404b, and semiconductor layer 403. In addition, an insulating film 407 in contact with the semiconductor layer 403 is provided to cover the thin film transistor 421. Semiconductor layer 403 and n<sup>+</sup>The layers 404a and 404b use In-Ga-Zn-O non-single crystal films. The thin film transistor 421 of this structure has the following characteristics: mobility 20cm<sup>2</sup>/Vs Above, the S value is 0.4V/dec or less. As a result, high-speed operation can be performed, and a drive circuit (source electrode driver or gate driver) such as a shift register and the pixel portion can be formed on the same substrate.
In addition, it is preferable to perform reverse sputtering in which argon gas is introduced into the gate insulating layer 402 and the wiring layers 405a, 405b to generate plasma before forming the semiconductor layer 403 by the sputtering method to remove dust adhering to the surface. .
For the semiconductor layer 403 and n<sup>+</sup>The layers 404a and 404b may be heat treated at 200 degrees to 600 degrees, typically 300 degrees to 500 degrees. For example, heat treatment is performed at 350 degrees for one hour in a nitrogen atmosphere. As for the timing of the heat treatment, as long as the semiconductor layer 403 and n<sup>+</sup>After the oxide semiconductor film of the layers 404a and 404b, there is no particular limitation.
In addition, the semiconductor layer 403 may also be treated with oxygen radicals.
In the thin film transistor 421, a gate insulating layer 402 is present in all regions including the thin film transistor 421, and a gate electrode is provided between the gate insulating layer 402 and the first substrate 441 of the substrate having an insulating surface Layer 401. Wiring layers 405a, 405b, and n are provided on the gate insulating layer 402<sup>+</sup>Layers 404a, 404b. In addition, the gate insulating layer 402, the wiring layers 405a, 405b, and n<sup>+</sup>A semiconductor layer 403 is provided on the layers 404a and 404b. In addition, although not shown, on the gate insulating layer 402, there is a wiring layer in addition to the wiring layers 405a and 405b, and the wiring layer extends to the outside of the peripheral portion of the semiconductor layer 403.
When the colored layer of the color light-transmitting resin layer is used as an interlayer film disposed on the thin film transistor, the aperture ratio of the pixel can be reduced, Reducing the intensity of light incident on the semiconductor layer of the thin film transistor can play a role in preventing and stabilizing the change in the electrical characteristics of the thin film transistor due to the sensitivity of the oxide semiconductor. In addition, the color light-transmitting resin layer can also be used as a color filter layer. When a color filter layer is provided on the opposite substrate side, although there is a concern that it is difficult to accurately align the pixel area with the element substrate on which thin film transistors are formed, resulting in degradation of image quality, the interlayer film is used as a color filter. The optical layer is directly formed on the element substrate side to more accurately control the formation area, and can correspond to pixels with fine patterns. In addition, since the same insulating layer is used as the interlayer film and the color filter layer, the manufacturing process is simplified and the liquid crystal display device can be manufactured at a lower cost.
By improving the contrast or viewing angle characteristics, a liquid crystal display device with higher image quality can be provided. In addition, the liquid crystal display device can be manufactured at lower cost and with high productivity.
In addition, the characteristics of the thin film transistor can be stabilized, and the reliability of the liquid crystal display device can be improved.
This embodiment mode can be implemented in appropriate combination with the structures described in the other embodiment modes.
Embodiment Mode 8
Other examples of thin film transistors that can be used in liquid crystal display devices in Embodiment Mode 1 to Embodiment Mode 5 are shown. In addition, the same materials and manufacturing methods can be used for the same parts as in Embodiment Mode 2 to Embodiment Mode 5, and detailed descriptions of the same parts or parts having the same functions are omitted.
11A and 11B show the source electrode layer and the drain electrode layer and the semiconductor layer so as not to be separated by n<sup>+</sup>An example of a liquid crystal display device with a thin-film transistor structure of layer-wise contact.
FIG. 11A is a plan view of the liquid crystal display device and shows one pixel. Fig. 11B is a cross-sectional view taken along the line Y1-Y2 of Fig. 11A.
In the plan view of FIG. 11A, similar to Embodiment Mode 2, a plurality of source electrode wiring layers (including the wiring layer 405a) are arranged in a state of being parallel to each other (extending in the vertical direction in the figure) and separated from each other. The plurality of gate wiring layers (including the gate electrode layer 401) extend in a direction (horizontal direction in the figure) substantially orthogonal to the source electrode wiring and are arranged to be separated from each other. The common wiring layer 408 is arranged at a position adjacent to each of the plurality of gate wiring layers and in a direction substantially parallel to the gate wiring layer, that is, a direction substantially orthogonal to the source electrode wiring layer (Figure In the horizontal direction). A substantially rectangular space is surrounded by the source electrode wiring layer, the common wiring layer 408, and the gate wiring layer, and the pixel electrode layer and the common wiring layer of the liquid crystal display device are arranged in this space. The thin film transistor 423 driving the pixel electrode layer is arranged in the upper left corner of the figure. The multiple pixel electrode layers and the thin film electrocrystalline system are arranged in a matrix.
The first substrate 441 and the second substrate 442 provided with the thin film transistor 423, the interlayer film 413 of the color light-transmitting resin layer, the first electrode layer 447, and the second electrode layer 446 are provided with a liquid crystal layer 444 sandwiched therebetween. fixed.
In the thin film transistor 423, the gate insulating layer 402 is present in all regions including the thin film transistor 423, and the gate insulating layer A gate electrode layer 401 is provided between 402 and the first substrate 441 of the substrate having an insulating surface. Wiring layers 405a and 405b are provided on the gate insulating layer 402. In addition, a semiconductor layer 403 is provided on the gate insulating layer 402 and the wiring layers 405a and 405b. In addition, although not shown, on the gate insulating layer 402, there is a wiring layer in addition to the wiring layers 405a and 405b, and the wiring layer extends to the outside of the peripheral portion of the semiconductor layer 403.
When the colored layer of the color light-transmitting resin layer is used as an interlayer film disposed on the thin film transistor, the intensity of light incident on the semiconductor layer of the thin film transistor can be reduced without reducing the aperture ratio of the pixel. Thereby, it can prevent and stabilize the change in the electrical characteristics of the thin film transistor due to the sensitivity of the oxide semiconductor. In addition, the color light-transmitting resin layer can also be used as a color filter layer. When a color filter layer is provided on the opposite substrate side, although there is a concern that it is difficult to accurately align the pixel area with the element substrate on which thin film transistors are formed, resulting in degradation of image quality, the interlayer film is used as a color filter. The optical layer is directly formed on the element substrate side to more accurately control the formation area, and can correspond to pixels with fine patterns. In addition, since the same insulating layer is used as the interlayer film and the color filter layer, the manufacturing process is simplified and the liquid crystal display device can be manufactured at a lower cost.
By improving the contrast or viewing angle characteristics, a liquid crystal display device with higher image quality can be provided. In addition, the liquid crystal display device can be manufactured at lower cost and with high productivity.
In addition, the characteristics of the thin film transistor can be stabilized, and the reliability of the liquid crystal display device can be improved.
This embodiment mode can be implemented in appropriate combination with the structures described in the other embodiment modes.
Example Mode 9
In the above embodiment modes, a liquid crystal material exhibiting a blue phase can be used as the liquid crystal layer. A liquid crystal display device using a liquid crystal layer exhibiting a blue phase will be described with reference to FIGS. 19A to 19D.
19A to 19D are cross-sectional views of a liquid crystal display device and its manufacturing process.
In FIG. 19A, an element layer 203 is formed on the first substrate 200 of the element substrate, and an interlayer film 209 is formed on the element layer 203.
The interlayer film 209 includes color light-transmitting resin layers 204a, 204b, 204c and light-shielding layers 205a, 205b, 205c, 205d, wherein light-shielding layers 205a, 205b, 205c are formed between the color light-transmitting resin layers 204a, 204b, and 204c, respectively And 205d. In addition, the included pixel electrode layer and common electrode layer are omitted in FIGS. 19A and 19D. For example, the pixel electrode layer and the common electrode layer can adopt the structures of Embodiment Mode 2 to Embodiment Mode 8, and a lateral electric field mode can be applied.
As shown in FIG. 19B, the first substrate 200 and the second substrate 201 of the counter substrate are fixed with sealing materials 202a and 202b so as to sandwich the liquid crystal layer 206. As a method of forming the liquid crystal layer 206, a dispenser method (dripping method) or an injection method of injecting liquid crystal using a capillary phenomenon after bonding the first substrate 200 and the second substrate 201 can be used.
The liquid crystal layer 206 may use a liquid crystal material exhibiting a blue phase. Due to rendering The reaction speed of the blue phase liquid crystal material is fast, and the high-speed reaction can be realized at 1 msec or less, and therefore, the high performance of the liquid crystal display device can be realized.
Liquid crystal materials exhibiting blue phase include liquid crystals and chiral reagents. Chiral reagents are used to align the liquid crystal into a helical structure to present a blue phase. For example, a liquid crystal material mixed with a chiral agent in an amount of 5 wt% or more can be used as the liquid crystal layer.
As the liquid crystal, thermotropic liquid crystal, low molecular liquid crystal, polymer liquid crystal, ferroelectric liquid crystal, antiferroelectric liquid crystal, etc. are used.
The chiral reagent uses materials that have good compatibility with liquid crystals and strong twisting power. In addition, it is preferable to use one of R-body or S-body instead of using a racemic mixture in which the ratio of R-body and S-body is 50:50.
The above-mentioned liquid crystal material exhibits a cholesteric phase, a cholesteric blue phase, a smectic phase, a smectic blue phase, a cubic phase, a chiral nematic phase, and an isotropy equal according to conditions.
The cholesteric blue phase and the smectic blue phase of the blue phase appear in a liquid crystal material having a relatively short cholesteric or smectic phase with a helical pitch of 500 nm or less. The alignment of the liquid crystal material has a double twist structure. Due to the order below the wavelength of visible light, the liquid crystal material is transparent, and the alignment order is changed by applying a voltage to produce an optical modulation effect. Because the blue phase is optically isotropic, there is no viewing angle dependence, and no alignment film is required. Therefore, the display image quality can be improved and the cost can be reduced. In addition, since there is no need to perform rubbing treatment on the alignment film, it is possible to prevent electrostatic discharge caused by rubbing treatment. discharge), and can reduce the defects and breakage of the liquid crystal display device in the manufacturing process. Therefore, the productivity of the liquid crystal display device can be improved. In particular, thin-film transistors using an oxide semiconductor layer have the following concern: the electrical characteristics of the thin-film transistors are greatly changed due to the influence of static electricity and exceed the design range. Therefore, it is more effective to use a blue phase liquid crystal material in a liquid crystal display device having a thin film transistor using an oxide semiconductor layer.
In addition, since the blue phase only appears in a narrow temperature range, in order to improve the temperature range and make it wider, it is preferable to add a photocurable resin and a photopolymerization initiator to the liquid crystal material and perform a polymer stabilization treatment. The polymer stabilization treatment is performed by irradiating a liquid crystal material containing a liquid crystal, a chiral agent, a photocurable resin, and a photopolymerization initiator with light of a wavelength at which the photocurable resin and the photopolymerization initiator can react. The polymer stabilization treatment may be performed by irradiating light to a liquid crystal material exhibiting an isotropic phase, or may be performed by irradiating light to a liquid crystal material exhibiting a blue phase by performing temperature control. For example, by controlling the temperature of the liquid crystal layer, the liquid crystal layer is irradiated with light in a state where the blue phase is present to perform polymer stabilization treatment. However, it is not limited to this. It is also possible to provide an isotropic phase within +10 degrees, preferably within +5 degrees, of the phase transition temperature between the blue phase and the isotropic phase. Light is irradiated to perform polymer stabilization treatment. The phase transition temperature between the blue phase and the isotropic phase refers to the temperature at which the blue phase changes to the isotropic phase when the temperature is raised, or the temperature at which the isotropic phase changes to the blue phase when the temperature is lowered. As an example of polymer stabilization treatment, the liquid crystal layer can be heated until it exhibits an isotropic phase, and then gradually cooled until it turns into a blue phase, and irradiated while maintaining the temperature of the blue phase Light. In addition, it is also possible to gradually heat the liquid crystal layer to transform it into an isotropic phase, and then within +10 degrees of the phase transition temperature between the blue phase and the isotropic phase, preferably within +5 degrees (showing each It is irradiated with light in the state of the same sex phase. In addition, when an ultraviolet curable resin (UV curable resin) is used as the photocurable resin contained in the liquid crystal material, the liquid crystal layer may be irradiated with ultraviolet rays. In addition, even when the blue phase is not present, the phase transition temperature between the blue phase and the isotropic phase is within +10 degrees, preferably within +5 degrees (state in which the isotropic phase is present) By irradiating it with light to perform polymer stabilization treatment, the reaction rate can be shortened to achieve a high-speed reaction, that is, the reaction rate is 1 msec or less.
The light-curable resin can use monofunctional monomers such as acrylate and methacrylate, and can also use monofunctional monomers such as diacrylate, triacrylate, dimethacrylate, and trimethacrylate. A polyfunctional monomer can also be a mixture of the above substances. In addition, the photocurable resin may have liquid crystallinity, non-liquid crystallinity, or both. The photocurable resin only needs to select a resin that can be cured according to the light of the reaction wavelength of the photopolymerization initiator used, and typically an ultraviolet curable resin can be used.
As the photopolymerization initiator, a radical polymerization initiator that generates radicals by light irradiation, an acid generator that generates an acid, and a base generator that generates a base can be used.
Specifically, as a liquid crystal material, a mixture of JC-1041XX (manufactured by Chisso Corporation) and 4-cyano-4'-pentylbiphenyl can be used, and as a chiral reagent, ZLI-4572 ( Japan Merck Co.), as the photocurable resin, 2-EHA (2-ethylhexyl acrylate), RM257 (Merck Co., Ltd.), trimethylolpropane triacrylate can be used as the photocurable resin. As a photopolymerization initiator, 2,2-dimethoxy-2-phenylacetophenone can be used.
The liquid crystal layer 206 is formed using a liquid crystal material containing a liquid crystal, a chiral agent, a photocurable resin, and a photopolymerization initiator.
As shown in FIG. 19C, the liquid crystal layer 206 is irradiated with light 207 to perform polymer stabilization treatment to form the liquid crystal layer 208. The light 207 uses light of a wavelength at which the photocurable resin and the photopolymerization initiator contained in the liquid crystal layer 206 react. By using the light irradiation to perform polymer stabilization treatment, the temperature range in which the liquid crystal layer 208 exhibits a blue phase can be improved and made wider.
When a photocurable resin such as an ultraviolet curable resin is used as the sealing material and the liquid crystal layer is formed by a drop method, the sealing material can also be cured by a light irradiation process of polymer stabilization treatment.
As shown in FIGS. 19A to 19D, when the liquid crystal display device adopts a structure in which the color filter layer and the light shielding layer are formed on the element substrate, there is no incident from the opposite substrate side due to the color filter layer and the light shielding layer. The light is absorbed or blocked, so the entire liquid crystal layer can be irradiated uniformly. As a result, it is possible to prevent the misalignment of the liquid crystal due to the unevenness of the photopolymerization, and the resulting display unevenness. In addition, since the thin-film transistor is shielded from light by the light-shielding layer, its electrical characteristics remain stable.
As shown in FIG. 19D, the polarizing plate 210a is disposed on the outer side of the first substrate 200 (the side opposite to the liquid crystal layer 208), and the polarizing plate 210b is disposed on the outer side of the second substrate 201 (the opposite side to the liquid crystal layer 208). On one side). In addition, in addition to the polarizing plate, an optical film such as a retardation plate and an anti-reflection film may be provided. For example, circular polarization using polarizing plates and retardation plates can be used. According to the above process, the liquid crystal display device can be completed.
In addition, when a large-sized substrate is used to manufacture multiple liquid crystal display devices (that is, one substrate is divided into a plurality of panels), the dividing process can be performed before the polymer stabilization treatment or before the polarizing plate is installed. Taking into account the effect of the dividing process on the liquid crystal layer (alignment disorder caused by force during the dividing process, etc.), it is preferable to attach the first substrate and the second substrate and before the polymer stabilization treatment Carry out the segmentation process.
Although not shown in the figure, a backlight, a side light, etc. may be used as the light source. The light source irradiates from the first substrate 200 side of the element substrate to the second substrate 201 on the visible side.
By improving the contrast and viewing angle characteristics to achieve high-speed response, it is possible to provide a liquid crystal display device with higher image quality and high performance. In addition, the liquid crystal display device can be manufactured at lower cost and with high productivity.
In addition, the characteristics of the thin film transistor can be stabilized, and the reliability of the liquid crystal display device can be improved.
This embodiment mode can be implemented in appropriate combination with the structures described in the other embodiment modes.
Embodiment Mode 10
By manufacturing thin film transistors and using the thin film transistors in the pixel area And the drive circuit can manufacture a liquid crystal display device with display function. In addition, a system-on-panel can be formed by integrally forming part or the whole of the driving circuit of the thin film transistor on the same substrate as the pixel portion.
The liquid crystal display device includes a liquid crystal element (also referred to as a liquid crystal display element) as a display element.
In addition, the liquid crystal display device includes a panel in which a display element is sealed, and a module in which an IC including a controller or the like is mounted in the panel. Furthermore, the present invention further relates to an element substrate, which corresponds to a mode before the display element is completed in the process of manufacturing the liquid crystal display device, and which is provided in each of the plurality of pixels to transfer current Means of supply to display elements. Specifically, the element substrate may be in a state where only the pixel electrode of the display element is formed, or may be in a state after forming a conductive film to be the pixel electrode and before forming the pixel electrode by etching, and any method may be adopted.
Note that the liquid crystal display device in this specification refers to an image display device, a display device, or a light source (including a lighting device). In addition, the liquid crystal display device also includes a module mounted with connectors such as FPC (flexible printed circuit), TAB (tape and reel automatic bonding) tape or TCP (tape carrier package); the printed circuit board is set on the TAB tape or A module at the TCP end; a module in which an integrated circuit (IC) is directly mounted on the display element by means of chip-on-glass (COG).
The appearance and cross-section of a liquid crystal display panel corresponding to an embodiment of a liquid crystal display device will be described with reference to FIGS. 12A1, 12A2, and 12B. Figure 12A1 and 12A2 uses a sealing material 4005 to seal the highly reliable thin film transistors 4010, 4011, and liquid crystal element 4013, including the oxide semiconductor film used as a semiconductor layer, formed on the first substrate 4001 on the second substrate 4006 and the second substrate 4006. A top view of the panel between the substrates 4001. FIG. 12B corresponds to a cross-sectional view taken along the line MN in FIGS. 12A1 and 12A2.
A sealing material 4005 is provided so as to surround the pixel portion 4002 and the scan line driving circuit 4004 provided on the first substrate 4001. In addition, a second substrate 4006 is provided on the pixel portion 4002 and the scan line driving circuit 4004. Therefore, the pixel portion 4002 and the scanning line driving circuit 4004 are sealed by the first substrate 4001, the sealing material 4005, and the second substrate 4006 together with the liquid crystal layer 4008.
In addition, in FIG. 12A1, a signal line driver circuit 4003 is mounted on the first substrate 4001 in a region different from the region surrounded by the sealing material 4005, and the signal line driver circuit 4003 uses a single crystal semiconductor film or a polycrystalline semiconductor film. The film is formed on a separately prepared substrate. In addition, FIG. 12A2 is an example in which a part of the signal line driver circuit is formed by a thin film transistor using an oxide semiconductor on the first substrate 4001, in which the signal line driver circuit 4003b is formed on the first substrate 4001 and is separated A signal line drive circuit 4003a formed of a single crystal semiconductor film or a polycrystalline semiconductor film is mounted on the prepared substrate.
In addition, there is no particular limitation on the connection method of the separately formed drive circuits, and the COG method, wire bonding method, TAB method, or the like can be used. FIG. 12A1 is an example of installing the signal line drive circuit 4003 by the COG method, and FIG. 12A2 is the example of installing the signal line by the TAB method An example of the drive circuit 4003.
In addition, the pixel portion 4002 and the scan line driving circuit 4004 provided on the first substrate 4001 include a plurality of thin film transistors. The thin film transistor 4010 included in the pixel portion 4002 and the thin film transistor 4011 included in the scan line driving circuit 4004 are illustrated in FIG. 12B. An insulating layer 4020 and an interlayer film 4021 are provided on the thin film transistors 4010 and 4011.
As the thin film transistors 4010 and 4011, a highly reliable thin film transistor including the oxide semiconductor films shown in Embodiment Mode 1 to Embodiment Mode 8 as the semiconductor layer can be used. The thin film transistors 4010 and 4011 are n-channel thin film transistors.
In addition, a pixel electrode layer 4030 and a common electrode layer 4031 are provided on the first substrate 4001, and the pixel electrode layer 4030 is electrically connected to the thin film transistor 4010. The liquid crystal element 4013 includes a pixel electrode layer 4030, a common electrode layer 4031, and a liquid crystal layer 4008. In addition, polarizing plates 4032 and 4033 are provided on the outer sides of the first substrate 4001 and the second substrate 4006, respectively. The structure of the pixel electrode layer 4030 and the common electrode layer 4031 can use the structure of Embodiment Mode 1. In this case, the following structure can be adopted, that is, the common electrode layer 4031 is disposed on the second substrate 4006 side, and the liquid crystal layer 4008 is interposed. The pixel electrode layer 4030 and the common electrode layer 4031 are stacked.
In addition, translucent glass, plastic, etc. can be used as the first substrate 4001 and the second substrate 4006. As the plastic, glass fiber reinforced plastic (FRP) board, polyvinyl fluoride (PVF) film, polyester film, or acrylic resin film can be used. In addition, it can also be made of PVF film or A thin sheet of polyester film sandwiched with aluminum foil.
In addition, reference numeral 4035 is a columnar spacer obtained by selectively etching an insulating film, and is provided for controlling the thickness (cell gap) of the liquid crystal layer 4008. In addition, spherical spacers can also be used. In addition, the liquid crystal display device using the liquid crystal layer 4008 preferably sets the thickness (cell interval) of the liquid crystal layer 4008 to be about 5 μm or more to 20 μm.
In addition, although FIGS. 12A1, 12A2, and 12B show examples of transmissive liquid crystal display devices, semi-transmissive liquid crystal display devices may also be used.
In addition, in the liquid crystal display devices of FIGS. 12A1, 12A2, and 12B, although an example in which a polarizing plate is provided on the outer side (viewing side) of a pair of substrates is shown, the polarizing plate may be provided on the inner side of the pair of substrates. . It can be set appropriately according to the material of the polarizing plate and the conditions of the manufacturing process. In addition, a light-shielding layer used as a black matrix can also be provided.
The interlayer film 4021 is a color light-transmitting resin layer and serves as a color filter layer. In addition, a part of the interlayer film 4021 may also be used as a light-shielding layer. In FIGS. 12A1, 12A2, and 12B, the light shielding layer 4034 is provided on the second substrate 4006 side in such a manner as to cover the upper portion of the thin film transistors 4010 and 4011. By providing the light-shielding layer 4034, the contrast ratio and the stability of the thin film transistor can be further improved.
When the colored layer of the color light-transmitting resin layer is used as the interlayer film 4021 disposed on the thin film transistor, the intensity of light incident on the semiconductor layer of the thin film transistor can be reduced without reducing the aperture ratio of the pixel , Which can prevent the thin film caused by the sensitivity of the oxide semiconductor The change in the electrical characteristics of the transistor stabilizes it. In addition, the color light-transmitting resin layer can also be used as a color filter layer. When a color filter layer is provided on the opposite substrate side, although there is a concern that it is difficult to accurately align the pixel area with the element substrate on which thin film transistors are formed, resulting in degradation of image quality, the interlayer film is used as a color filter. The optical layer is directly formed on the element substrate side to more accurately control the formation area, and can correspond to pixels with fine patterns. In addition, since the same insulating layer is used as the interlayer film and the color filter layer, the manufacturing process is simplified and the liquid crystal display device can be manufactured at a lower cost.
In addition, a structure covered with an insulating layer 4020 serving as a protective film of a thin film transistor may also be adopted, but it is not limited to this.
In addition, since the protective film is used to prevent the intrusion of pollutant impurities such as organic matter, metal matter, and water vapor suspended in the atmosphere, a dense film is preferably used. Use a sputtering method, etc. and use a single layer or a single layer of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a silicon oxynitride film, an aluminum oxide film, an aluminum nitride film, an aluminum oxynitride film, or an aluminum oxynitride film What is necessary is to laminate them to form a protective film.
In addition, annealing (300 to 400 degrees) of the semiconductor layer may be performed after forming the protective film.
In addition, when forming an insulating layer having light transmittance as a planarizing insulating film, an organic material having heat resistance such as polyimide, acrylic resin, benzocyclobutene, polyamide, epoxy, or the like can be used. In addition, in addition to the above-mentioned organic materials, low dielectric constant materials (low-k materials), silicone-based resins, PSG (phosphosilicate glass), BPSG (borophosphosilicate glass), and the like can also be used. In addition, the insulating layer may be formed by laminating a plurality of insulating films formed of these materials.
There are no particular restrictions on the method of forming the laminated insulating film, and sputtering, SOG, spin coating, dipping, spraying, droplet spraying methods (inkjet, screen printing, offset printing, etc.) can be used depending on the material. , Doctor blade, roller coater, curtain coater, knife coater, etc. In the case of using a material solution to form the insulating layer, the annealing of the semiconductor layer (200° to 400°) can also be carried out at the same time during the firing process. By combining the firing process of the insulating layer and the annealing of the semiconductor layer, the liquid crystal display device can be manufactured efficiently.
As the pixel electrode layer 4030 and the common electrode layer 4031, a light-transmitting conductive material such as indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, and indium tin oxide containing titanium oxide can be used. , Indium tin oxide (hereinafter referred to as ITO), indium zinc oxide, indium tin oxide added with silicon oxide, etc.
In addition, the pixel electrode layer 4030 and the common electrode layer 4031 may be formed using a conductive composition containing a conductive polymer (also referred to as a conductive polymer).
In addition, various signals and potentials supplied to the separately formed signal line driver circuit 4003, scanning line driver circuit 4004, or pixel portion 4002 are supplied from the FPC 4018.
In addition, since the thin film transistor is easily damaged due to static electricity or the like, it is preferable to arrange the gate line or the source electrode line and the protective circuit for driving the circuit on the same substrate. The protection circuit is preferably composed of a non-linear element using an oxide semiconductor.
In FIGS. 12A1, 12A2, and 12B, the connection terminal electrode 4015 is formed of the same conductive film as the pixel electrode layer 4030, and the terminal The electrode 4016 is formed of the same conductive film as the source electrode layer and drain electrode layer of the thin film transistors 4010 and 4011.
The connection terminal electrode 4015 is electrically connected to the terminal of the FPC 4018 through the anisotropic conductive film 4019.
In addition, although an example in which the signal line driver circuit 4003 is separately formed and mounted on the first substrate 4001 is shown in FIGS. 12A1, 12A2, and 12B, it is not limited to this structure. The scanning line driving circuit can be separately formed and mounted, or only a part of the signal line driving circuit or a part of the scanning line driving circuit can be formed separately and mounted.
FIG. 16 shows an example in which a liquid crystal display module is constituted as the liquid crystal display device disclosed in this specification.
FIG. 16 is an example of a liquid crystal display module. A sealing material 2602 is used to fix the element substrate 2600 and the counter substrate 2601, and an element layer 2603 including TFT and the like, a display element 2604 including a liquid crystal layer, and a display element 2604 including a liquid crystal layer are provided therebetween. The interlayer film 2605 of the color light-transmitting resin layer of the filter layer forms the display area. When performing color display, an interlayer film 2605 including a color light-transmitting resin layer is required, and when the RGB method is adopted, a color light-transmitting resin layer corresponding to red, green, and blue is provided for each pixel. A polarizing plate 2606, a polarizing plate 2607, and a diffusion plate 2613 are arranged outside the element substrate 2600 and the counter substrate 2601. The light source is composed of a cold cathode tube 2610 and a reflector 2611. The circuit board 2612 is connected to the wiring circuit portion 2608 of the element board 2600 by a flexible circuit board 2609, and external circuits such as a control circuit and a power supply circuit are assembled. As a light source, a white diode can also be used. In addition, it can also be used in the polarizing plate and the liquid crystal layer Laminating is carried out with the phase difference plate interposed therebetween.
In addition, the liquid crystal display module according to Embodiment Mode 1 can adopt MVA (Multi-quadrant Vertical Alignment) mode, PVA (Patterned Vertical Alignment) mode, ASM (Axisymmetric Alignment Microcell) mode, OCB (Optical Compensation Birefringence) mode , FLC (ferroelectric liquid crystal) mode, AFLC (anti-ferroelectric liquid crystal) mode, etc.
Through the above process, a highly reliable liquid crystal display panel can be manufactured as a liquid crystal display device.
This embodiment mode can be implemented in appropriate combination with the structures described in the other embodiment modes.
Embodiment Mode 11
The liquid crystal display device disclosed in this specification can be applied to various electronic devices (including game consoles). Examples of electronic devices include television devices (also called televisions or television receivers), monitors used in computers, etc., digital cameras, digital video cameras, digital photo frames, and mobile phones (also called cellular phones or mobile phones). Large game machines such as portable telephone devices), portable game consoles, portable information terminals, sound reproduction devices, pachinko machines, etc.
FIG. 13A shows an example of a television device 9600. In the television device 9600, a display portion 9603 is incorporated in the housing 9601. The display unit 9603 can display images. In addition, a structure in which a bracket 9605 is used to support the housing 9601 is shown here.
You can use the operating switch provided in the housing 9601, and The remote control 9610 is provided to operate the television device 9600. By using the operation keys 9609 of the remote control 9610, the channel and volume can be operated, and the image displayed on the display portion 9603 can be operated. In addition, a configuration in which the remote control 9610 is provided with a display portion 9607 that displays information output from the remote control 9610 may be adopted.
In addition, the television device 9600 adopts a structure including a receiver, a modem, and the like. You can receive general TV broadcasts by using the receiver. Furthermore, by connecting the modem to a wired or wireless communication network, it can also be one-way (from sender to receiver) or two-way (between sender and receiver or between receivers, etc.) ) Information communication.
FIG. 13B shows an example of a digital photo frame 9700. For example, in the digital photo frame 9700, the housing 9701 is equipped with a display portion 9703. The display portion 9703 can display various images. For example, by displaying image data taken with a digital camera, etc., it can perform the same functions as a general photo frame.
In addition, the digital photo frame 9700 has a structure including an operation unit, external connection terminals (USB terminals, terminals that can be connected to various cables such as a USB cable, etc.), a recording medium insertion unit, and the like. These structures can also be assembled on the same surface as the display part, but it is better to provide them on the side or back to improve the design. For example, it is possible to insert a memory storing image data taken with a digital camera into the recording medium insertion portion of the digital photo frame and extract the image data, and then display the extracted image data on the display portion 9703.
In addition, the digital photo frame 9700 can also adopt a structure for sending and receiving information wirelessly. You can also extract the desired shadow wirelessly. The structure of image data and display.
FIG. 14A shows a portable game machine, which is composed of two housings, a housing 9881 and a housing 9891, and can be connected in an open and closed manner by a connecting portion 9893. The housing 9881 is equipped with a display portion 9882, and the housing 9891 is equipped with a display portion 9883. In addition, the portable game machine shown in FIG. 14A also has a speaker portion 9884, a recording medium insertion portion 9886, an LED light 9890, an input unit (operation keys 9885, connection terminals 9887, and a sensor 9888 (including functions for measuring the following factors) : Force, displacement, position, speed, acceleration, angular velocity, number of rotations, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, electricity, radiation, flow, humidity, Inclination, vibration, smell or infrared) and microphone 9889) etc. Of course, the structure of the portable game machine is not limited to the above-mentioned structure, as long as the structure is equipped with at least the liquid crystal display device disclosed in this specification, and a structure in which other accessory devices are appropriately provided can be adopted. The portable game machine shown in FIG. 14A has the following functions: read out the program or data stored in the recording medium and display it on the display unit; and realize information by wireless communication with other portable game machines Shared. In addition, the functions of the portable game machine shown in FIG. 14A are not limited to these, and may have various functions.
FIG. 14B shows an example of a slot machine 9900 which is a kind of large game machine. A display part 9903 is installed in the housing 9901 of the slot machine 9900. In addition, the slot machine 9900 also has operating means such as a start lever or a stop switch, coin slot, and speakers. Of course, the structure of the slot machine 9900 is not limited to this, as long as it has at least this The structure of the liquid crystal display device disclosed in the specification is sufficient, and a structure in which other accessory devices are appropriately provided can be adopted.
FIG. 15A shows an example of a mobile phone 1000. The mobile phone 1000 is equipped with operation buttons 1003, an external connection port 1004, a speaker 1005, a microphone 1006, etc., in addition to the display unit 1002 mounted on the housing 1001.
The mobile phone 1000 shown in FIG. 15A can touch the display part 1002 with a finger or the like to input information. In addition, operations such as making a call or creating an e-mail can be performed by touching the display unit 1002 with a finger or the like.
The screen of the display unit 1002 mainly has three modes. The first is a display mode based mainly on the display of images, the second is an input mode based on the input of information such as text, and the third is a display + input mode in which the two modes of display mode and input mode are mixed.
For example, in the case of making a call or creating an e-mail, it is sufficient to set the display unit 1002 to a character input mode mainly for character input, and perform an input operation of characters displayed on the screen. In this case, it is preferable to display a keyboard or number buttons on most of the screen of the display unit 1002.
In addition, the mobile phone 1000 is equipped with a detection device having a gyroscope, an acceleration sensor and other sensors for detecting inclination to determine the direction of the mobile phone 1000 (vertical or horizontal), thereby The screen display of the display unit 1002 can be automatically switched.
The screen mode is switched by touching the display part 1002 or operating with the operation button 1003 of the housing 1001. It can also be displayed according to the display The image type on the part 1002 switches the screen mode. For example, when the video signal displayed on the display part is a dynamic image data, the screen mode is switched to the display mode, and when the video signal displayed on the display part is text data, the screen mode is switched to the input mode.
In addition, when the signal detected by the light sensor of the display part 1002 is detected in the input mode and it is known that there is no touch operation input on the display part 1002 for a certain period of time, the screen mode can also be changed from the input mode Switch to display mode for control.
The display part 1002 can also be used as an image sensor. For example, by touching the display part 1002 with a palm or a finger, palm prints, fingerprints, etc. can be photographed, and personal identification can be performed. In addition, by using a backlight that emits near-infrared light or a sensing light source that emits near-infrared light in the display unit, it is also possible to photograph finger veins, palm veins, and the like.
Fig. 15B is also an example of a mobile phone. The mobile phone of FIG. 15B includes: a display device 9410 having a display portion 9412 and operation buttons 9413 in a housing 9411, and an operation button 9402 in the housing 9401, an external input terminal 9403, a microphone 9404, a speaker 9405, and an incoming call The communication device 9400 of the light-emitting portion 9406 that emits light at any time, and the display device 9410 with a display function and the communication device 9400 with a telephone function can be separated along the two directions indicated by the arrows. Therefore, the short axis of the display device 9410 and the communication device 9400 can be connected to each other, or the long axis of the display device 9410 and the communication device 9400 can be connected to each other. In addition, when only the display function is required, the communication device 9400 and the display device 9410 may be separated and the display device 9410 may be used alone. Communication device The 9400 and the display device 9410 can send and receive images or input information through wireless communication or wired communication, and each has a rechargeable battery.
This specification is prepared based on Japanese Patent Application No. 2008-304243, which was accepted at the Japan Patent Office on November 28, 2008, and the content of the application is included in this specification.
45 members in 6 offices
Priority claims2
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|---|---|---|---|
| 2008304243 | Japan | – | |
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| JP6845890B2 | Japan | B2 | |
| US10985282B2 | United States of America | B2 | |
| US2021265505A1 | United States of America | A1 | |
| TWI749283B | Taiwan Province of China | B | |
| JP6983209B2 | Japan | B2 | |
| JP2022022257A | Japan | A | |
| US11869978B2 | United States of America | B2 | |
| JP2024079730A | Japan | A |
1 legal event, as the office reported them to INPADOC
Events
| Event | Code | |
|---|---|---|
| Annulment or lapse of patent due to non-payment of feesLapsedMM4A | MM4A |
Numbers
- Publication
- 201719255
- Application
- 105136657
Titles2
- English
- LIQUID CRYSTAL DISPLAY DEVICE
- Chinese
- 液晶顯示裝置
Classification
- CPC, 10
- G02F1/133514
- G02F1/136209
- H10D30/6755
- G02F1/136222
- H10D86/60
- H10D86/423
- H10D86/451
- G02F1/1368
- H01B3/10
- H10D30/6713
- IPC, 5
- G02F1 1343
- G02F1 136
- H01L27 12
- H10D30 01
- H10D30 67