Display device and manufacturing method thereof

The present invention relates to a semiconductor device having pixel electrodes, particularly a display device. In particular, the present invention relates to a semi-transmissive liquid crystal display device having a reflection region and a transmission region in one pixel.

The display device includes a self-luminous display device and a non-light emitting display device, and the liquid crystal display device is the most typical non-light emitting display device. Since it is non-emission, the liquid crystal display device is usually irradiated with light from a backlight for display.

However, a transmissive liquid crystal display device using light from a backlight has a problem that it is easy to see the displayed image in a normal room, but it is difficult to see the displayed image in sunlight. In particular, in electronic devices frequently used outdoors such as cameras, personal digital assistants, and mobile phones, the influence of this problem is large.

Therefore, a semi-transmissive liquid crystal display device has been developed so that a good image can be displayed both indoors and outdoors. The semi-transmissive liquid crystal display device has a reflection region and a transmission region in one pixel. A transparent electrode is provided in the transmissive region, through which light is transmitted to function as a transmissive liquid crystal display device. On the other hand, the reflective region has a reflective electrode, which reflects light to function as a reflective liquid crystal display device. By doing so, a good image can be displayed both indoors and outdoors.

Such liquid crystal display devices include a passive matrix type and an active matrix type. When manufacturing an active matrix type display device, generally, a wiring to be connected to a semiconductor layer of a thin film transistor (TFT) is formed, and a conductive film to be a pixel electrode is formed on the wiring.

The pixel electrodes include a reflection electrode in the reflection region and a transparent electrode in the transmission region. Each has a different shape. Therefore, a resist mask for forming a reflective electrode and a resist mask for forming a transparent electrode are required (see, for example, Patent Documents 1 to 5).<patcit num="1"><text>Japanese Unexamined Patent Publication No. 2002-229016</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 2004-46223</text></patcit><patcit num="3"><text>Japanese Patent Application Laid-Open No. 2005-338829</text></patcit><patcit num="4"><text>Japanese Unexamined Patent Publication No. 2004-334205</text></patcit><patcit num="5"><text>Japanese Unexamined Patent Publication No. 2004-109797</text></patcit>

<p> In a conventional semi-transmissive liquid crystal display device, a resist mask is required for each layer when forming a reflective electrode and a transparent electrode. That is, a resist mask for forming the reflective electrode and a resist mask for etching the film laminated with the transparent electrode are required, and the number of manufacturing steps is increased accordingly. Therefore, the manufacturing cost of a semiconductor device such as a display device is high, and the manufacturing time for forming the electrode pattern is long.</p><p> Therefore, an object of the present invention is to reduce the number of resist masks used and shorten the manufacturing process.</p>

<p> The present invention has a transistor, a transparent electrode electrically connected to the transistor, a reflective electrode electrically connected to the transparent electrode, and a holding capacitance electrically connected to the transistor, and the reflection. Provided is a display device characterized in that at least a part of the holding capacity is formed under the electrode and the entire lower surface of the reflective electrode is in contact with the upper surface of the transparent electrode.</p><p> Further, the present invention includes a transistor, a transparent electrode electrically connected to the transistor, and a reflecting electrode electrically connected to the transparent electrode, and the transparent electrode or at least one of the reflecting electrodes is Provided is a display device having a slit, wherein the entire lower surface of the reflective electrode is in contact with the upper surface of the transparent electrode.</p><p> Further, the present invention has a transistor, a transparent electrode electrically connected to the transistor, a reflective electrode electrically connected to the transparent electrode, and a holding capacitance electrically connected to the transistor. The transparent electrode or at least one of the reflective electrodes has a slit, at least a part of the holding capacity is formed under the reflective electrode, and the entire lower surface of the reflective electrode is in contact with the upper surface of the transparent electrode. A display device characterized by the fact that the display device is provided is provided.</p><p> Further, the present invention has a transistor, a transparent electrode electrically connected to the transistor, a reflective electrode electrically connected to the transparent electrode, and a holding capacitance electrically connected to the transistor. At least a part of the holding capacitance is formed under the reflective electrode, at least a part of the transistor is formed under the reflective electrode, and the entire lower surface of the reflective electrode is in contact with the upper surface of the transparent electrode. A display device characterized by being present is provided.</p><p> Further, the present invention has a transistor and a pixel electrode electrically connected to the transistor, the pixel electrode has a transparent electrode and a reflective electrode, and the entire lower surface of the reflective electrode is the transparent electrode. Provided is a display device characterized in that the film thickness of the transparent electrode in a region in contact with the reflective electrode is thicker than the film thickness of the transparent electrode in a region not in contact with the reflective electrode. Will be done.</p><p> Further, the present invention provides a display device characterized in that, in the above configuration, a liquid crystal layer is arranged between the reflective electrode and the counter electrode.</p><p> Further, in the present invention, a transistor is formed on a substrate, an insulating film is formed on the transistor, a transparent conductive film is formed on the insulating film, and a reflective conductive film is formed on the transparent conductive film. Then, using an exposure mask having a translucent portion on the reflective conductive film, a resist pattern having a thick region and a region thinner than the region is formed, and the resist pattern is used. Provided is a method for manufacturing a display device, which comprises forming a transparent electrode made of the transparent conductive film and a reflective electrode made of the reflective conductive film.</p><p> Further, in the present invention, a transistor is formed on a substrate, an insulating film is formed on the transistor, a transparent conductive film is formed on the insulating film, and a reflective conductive film is formed on the transparent conductive film. Then, using an exposure mask having a translucent portion on the reflective conductive film, a resist pattern having a thick region and a region thinner than the region is formed, and the resist pattern is used. The reflective conductive film and the transparent conductive film are etched, a part of the resist pattern is removed, and the reflective conductive film is etched using the resist pattern from which the part is removed. A method of making a display device is provided.</p><p> In this way, one resist pattern can be used to form a transparent electrode and a reflective electrode in contact with a part of the transparent electrode. Since two patterns of the transparent electrode and the reflective electrode can be formed by using one resist pattern, the manufacturing process can be shortened and a low-cost display device can be realized.</p><p>In the present invention, the types of transistors that can be applied are not limited, and a thin film transistor (TFT) using a non-single crystal semiconductor film typified by amorphous silicon or polycrystalline silicon, a semiconductor substrate, or an SOI substrate is used. The formed transistor, MOS type transistor, junction type transistor, bipolar transistor, transistor using compound semiconductor such as ZnO and a-InGaZnO, transistor using organic semiconductor and carbon nanotube, and other transistors can be applied. Further, the type of substrate on which the transistor is arranged is not limited, and can be arranged on a single crystal substrate, an SOI substrate, a glass substrate, a plastic substrate, or the like.</p><p>The configuration of the transistor is not particularly limited. For example, it may have a multi-gate structure in which the number of gate electrodes is two or more, a structure in which gate electrodes are arranged above and below the channel, or a gate electrode is arranged above the channel. The structure may be such that the gate electrode is arranged under the channel, the structure may be a normal stagger structure, the structure may be an inverted stagger structure, or the channel region is divided into a plurality of regions. It may be connected in parallel, connected in series, the source electrode or drain electrode may overlap the channel (or a part thereof), or the LDD region (low concentration). There may be an impurity region).</p><p>In the present invention, being connected is synonymous with being electrically connected. Therefore, in the configuration disclosed by the present invention, in addition to the predetermined connection relationship, other elements (for example, switches, transistors, capacitive elements, resistance elements, diodes, etc.) that enable electrical connection are arranged between them. You may.</p><p>The switch shown in the present invention is not limited to a specific switch. Electrical and mechanical switches can be applied. It is not limited as long as it can control the flow of electric current. It may be a transistor, a diode (PN diode, PIN diode, Schottky diode, diode-connected transistor, etc.), or a logic circuit combining them. Therefore, when a transistor is used as a switch, the polarity (conductive type) of the transistor is not particularly limited because the transistor operates as a mere switch. However, when it is desirable that the off-current is small, it is desirable to use a transistor having the polarity with the smaller off-current. Transistors with a small off-current include those provided with an LDD region and those having a multi-gate structure. Also, if the potential of the source terminal of the transistor that operates as a switch is close to the low potential side power supply (Vss, GND, 0V, etc.), use the N channel type, and conversely, the potential of the source terminal is high potential. It is desirable to use the P-channel type when operating in a state close to the side power supply (Vdd, etc.). This is because the absolute value of the gate-source voltage can be increased, which makes it easier for the transistor to function as a switch. A CMOS type switch may be used by using both the N channel type and the P channel type.</p><p>It should be noted that the arrangement in the pixels is not limited to a specific display element. Examples of display elements arranged in pixels include EL elements (organic EL elements, inorganic EL elements or EL elements containing organic and inorganic substances), electron emitting elements, liquid crystal elements, electronic inks, grating light valves (GLV), and the like. Display media whose contrast changes due to electromagnetic action, such as plasma displays (PDPs), digital micromirror devices (DMDs), piezoelectric ceramic displays, and carbon nanotubes, can be applied. In addition, as a display device using an EL element, an EL display, and as a display device using an electron emitting element, a liquid crystal such as a field emission display (FED) or a SED type flat display (SED: Surface-conduction Electron-emitter Disply). A display device using an element includes a liquid crystal display, and a display device using electronic ink includes electronic paper.</p><p>In the present invention, one pixel means one color element. Therefore, in the case of a full-color display device consisting of R (red), G (green), and B (blue) color elements, the minimum unit of an image is composed of three pixels, an R pixel, a G pixel, and a B pixel. It shall be done. The color element is not limited to three colors, and may be more than that, for example, RGBW (W is white). When describing one pixel (three colors), it is a case where three pixels of R, G, and B are considered as one pixel.</p><p>In the present invention, the pixels are arranged in a matrix not only when they are arranged in a so-called stripe, but also when a full-color display is performed using three color elements (for example, RGB). It is assumed that the dots of are so-called delta-arranged. The color element is not limited to three colors, and may be more than that, for example, RGBW. Further, the size of the region may be different for each dot of the color element.</p><p>A transistor is an element having at least three terminals including a gate electrode, a drain region (or drain electrode), and a source region (or source electrode), and a channel between the drain region and the source region. It has a forming region. Here, since the source region and the drain region change depending on the structure of the transistor, operating conditions, and the like, it is difficult to limit which is the source region or the drain region. Therefore, in this embodiment, the regions that function as the source region or the drain region are referred to as the first terminal and the second terminal.</p><p>In the present invention, the semiconductor device means a device having a circuit including a semiconductor element (transistor, diode, etc.). Further, it may be a general device that can function by utilizing the semiconductor characteristics. The display device is not only a display panel main body in which a plurality of pixels including display elements such as liquid crystal elements and EL elements and peripheral drive circuits for driving those pixels are formed on a substrate, but also a flexible printed circuit (a flexible printed circuit board). Includes those with FPC) and printed circuit boards (PWB) attached. Further, the light emitting device refers to a display device using a self-luminous display element such as an EL element or an element used in an electron emitting element.</p>

<p> According to the present invention, the number of manufacturing steps can be reduced as compared with the conventional case, and the manufacturing cost of a semiconductor device or a display device can be reduced.</p>

Hereinafter, embodiments of the present invention will be described. However, the present invention can be implemented in many different embodiments to the extent practicable. It is easily understood by those skilled in the art that the form and details of the present invention can be changed in various ways without departing from the spirit and scope thereof. Therefore, the interpretation is not limited to the description of the present embodiment. In addition, the embodiments shown below can be combined as appropriate.

(Embodiment 1) FIGS. 1 to 2 describe a manufacturing method for forming a reflective electrode and a transparent electrode.

First, the conductive film 106 is formed on the insulating film 107 by a sputtering method, a printing method, a CVD method, an inkjet method, or the like. The conductive film 106 may be a transparent conductive film or may have reflectivity. In the case of a transparent conductive film, for example, an indium tin oxide (ITO) film in which indium oxide is mixed with tin oxide, an indium tin oxide (ITSO) film in which indium tin oxide (ITO) is mixed with silicon oxide, and the like. Indium zinc oxide (IZO) film in which zinc oxide is mixed with indium oxide, zinc oxide film, tin oxide film, silicon (Si) containing phosphorus and boron, and the like can be used. IZO is a transparent conductive material formed by sputtering using a target in which 2 to 20 wt% zinc oxide (ZnO) is mixed with ITO, but the composition ratio and the like are not limited to this.

The conductive film 106 is formed on the insulating film 107, and then the conductive film 105 is laminated on the conductive film 106. The conductive film 106 and the conductive film 105 can be continuously formed by sputtering. As a result, the number of steps can be reduced.

The conductive film 105 is preferably a material having low resistance or a material having high reflectance. For example, Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, Au, Pt, Nb, Si, Zn, Fe, Ba, Ge and the like and alloys thereof can be used. Further, a two-layer structure in which these are laminated may be used. In that case, a two-layer laminated structure using Al (or an alloy containing Al as a main material) and metals such as Ti, Mo, Ta, Cr, and W may be used. Further, a three-layer laminated structure may be used. In that case, a three-layer laminated structure in which Al (or an alloy containing Al as a main material) is sandwiched between metals such as Ti, Mo, Ta, Cr, and W may be used. By arranging metals such as Ti, Mo, Ta, Cr, and W around Al (or an alloy containing Al as the main material) in this way, defects are reduced when connecting to another electrode or wiring. can do. For example, connecting an ITO film or the like with Al (or an alloy containing Al as a main material) may cause problems such as electrolytic corrosion. Further, when Al (or an alloy containing Al as a main material) is connected to a Si film or the like, Al and the Si film may react with each other. These can be reduced by forming a multi-layer structure.

When an ITO film is used as the conductive film, a step of heat-treating the ITO film to crystallize it is required. In that case, it is advisable to form an ITO film by sputtering, and after firing, form a conductive film 105. If an ITSO film is used, the number of steps can be reduced because the step of crystallization is not required.

Next, after forming (coating) the resist film 104 on the entire surface of the conductive film 105, exposure is performed using the exposure mask shown in FIG. 1 (A).

In FIG. 1A, the exposure mask has a light-shielding portion 101a through which the exposure light is shielded and a semipermeable membrane 101b through which the exposure light partially passes. A semipermeable membrane 102 is provided on the semipermeable membrane 101b to reduce the light intensity of the exposure light. The light-shielding portion 101a is configured by laminating a metal film 103 on a semipermeable membrane 102. The width of the light-shielding portion 101a is shown as t1, and the width of the semipermeable membrane portion 101b is shown as t2. Here, an example in which a semipermeable membrane is used for the semipermeable membrane is shown, but the present invention is not limited to this, and the semipermeable membrane may be any one that reduces the light intensity of the exposure light. Further, a diffraction grating pattern may be used for the semipermeable membrane.

That is, what is called a halftone or a gray tone may be used for the semipermeable membrane.

When the resist film is exposed using the exposure mask shown in FIG. 1 (A), a non-exposed region and an exposed region are formed. At the time of exposure, the exposed region is formed by the light wrapping around at the light-shielding portion 101a or passing through the semipermeable membrane 101b.

Then, when the development is performed, the exposed region is removed, and as shown in FIG. 1 (B), a resist pattern 104a having roughly two film thicknesses is obtained on the conductive film 105. The resist pattern 104a has a region having a thick film thickness and a region having a film thickness thinner than the region, and for the region having a thin film thickness, the film thickness is adjusted by adjusting the exposure energy or the transmittance of the semipermeable membrane 102. Can be adjusted.

Next, the conductive film 105 and the conductive film 106 are etched by dry etching. Dry etching is performed by a dry etching apparatus using a high-density plasma source such as ECR (Electron Cyclotron Resonance) or ICP (Inductively Coupled Plasma).

Then, as shown in FIG. 1C, the conductive film 105a and the conductive film 106a are formed.

Although an example using an ICP type etching apparatus is shown here, the present invention is not limited to this, and for example, a parallel plate type etching apparatus, a magnetron type etching apparatus, an ECR type etching apparatus, and a helicon type etching apparatus may be used. ..

The conductive film 105 and the conductive film 106 may be etched by wet etching. However, since dry etching is suitable for microfabrication, dry etching is preferable. Further, since the materials of the conductive film 105 and the conductive film 106 and the insulating film 107 are significantly different, a large etching selectivity can be obtained between the conductive film 105 and the conductive film 106 and the insulating film 107 even if dry etching is performed. Further, in order to increase the etching selectivity of both, at least the uppermost layer of the insulating film 107 may be formed of a silicon nitride film.

In this way, as shown in FIG. 1C, a pattern composed of a laminate of the conductive film 106a and the conductive film 105a is formed on the insulating film 107.

The resist pattern 104a (part) is then ashed or etched (FIG. 2 (A)). By this step, the thin region of the resist pattern 104a is etched, and the overall film thickness of the resist pattern 104a is reduced by the film thickness of the thin region. Then, the resist pattern 104b is formed. Since the resist pattern 104a is etched not only in the film thickness direction but also in the width direction, the width of the resist pattern 104b is smaller than the widths of the conductive films 105a and 106a. Therefore, the side surface of the resist pattern 104b does not coincide with the side surface of the conductive film underneath, and the side surface of the resist pattern 104b is retracted. In FIG. 2B, the resist pattern 104b is asymmetrical.

Next, the conductive film 105a is etched using the resist pattern 104b to form the conductive film 105b (FIG. 2 (B)). At this time, the material of the conductive film 105a preferably has a high selectivity with that of the conductive film 106a so that the conductive film 106a is not unnecessarily etched at the same time. For example, the material includes Ti, Mo, Cr, Al, Nd and the like and their alloys, and a laminated structure made of these materials may be used. Then, a conductive film 105b having a pattern smaller than that of the conductive film 106a is formed.

The etching of the conductive film 105b of FIGS. 2 (A) to 2 (B) may be performed by dry etching or wet etching, but FIG. 2 illustrates the case of dry etching. The conductive film 105b is formed so that the side surface substantially coincides with the side surface of the resist pattern 104b. One side surface of the conductive film 105b is on an extension of one side surface of the resist pattern 104b, and the other side surface coincides with the other side surface of the resist pattern 104b.

By performing dry etching, fine processing becomes possible. However, when the conductive film 105b is formed, a part of the conductive film 106a is also etched.

On the other hand, when the conductive film 105b is wet-etched, the etching proceeds isotropically, so that the conductive film 105b smaller than the resist pattern 104b is formed. The side surface of the resist pattern 104b and the side surface of the conductive film 105b do not match. Therefore, even if the same resist pattern 104b is used as a mask, a smaller conductive film 105b is formed by forming by wet etching rather than by dry etching.

By performing wet etching, it is possible to obtain a sufficiently large etching selection ratio.

When the conductive film 106a is formed by dry etching, its side surface is substantially perpendicular to the substrate surface or at an angle θ close to 90 degrees.₁Have. On the other hand, when the conductive film 105b is formed by wet etching, the side surface thereof has an acute angle θ with respect to the substrate surface due to isotropic etching.₂Have. Therefore, the angle θ between the side surfaces of the conductive film 106a and the conductive film 105b₁And angle θ₂Comparing, θ₁&gt; θ₂It has become. The angle θ₁Is the inclination angle of the conductive film 106a with respect to the surface of the substrate or the insulating film 107, and is an angle θ.₂Is the inclination angle of the side surface of the conductive film 105b with respect to the surface of the substrate or the insulating film 107, and is θ.₁, Θ₂Both are in the range of 0 ° to 90 °.

When the conductive film 105b and the conductive film 106a have a laminated structure, the etching rate may differ depending on each layer. Along with this, the angles formed by the side surfaces of each layer with respect to the substrate surface may also differ. Therefore, at that time, the angle formed by the side surface of the lowermost film with respect to the substrate surface is θ.₂And.

It should be noted that the side surfaces of the conductive film 105b and the conductive film 106a may have irregularities instead of being smooth surfaces. In that case, the angle θ₁And angle θ₂May be determined as appropriate. For example, draw a rough straight line or curve on an uneven side surface and use it to make an angle θ.₁And angle θ₂Can be determined. Also, based on the uneven side surface, a plurality of angles θ₁And angle θ₂And the average value is the angle θ₁And angle θ₂Can be. The most rational method should be used.

From the above, the conductive film 105b is formed by an etching method of either a dry etching method or a wet etching method. Regardless of which etching method is used, the conductive film 105b having a side surface recessed from the side surface of the conductive film 106a is formed. One of the factors is that the resist pattern 104a, which is a mask for forming the conductive film 106a, and the resist pattern 104b, which is a mask for forming the conductive film 105b, are different in size, and the resist pattern 104b is smaller. Is.

Then, the resist pattern 104b is removed (Fig. 2 (C)). Then, an electrode made of the conductive film 105b and the conductive film 106a is formed. The conductive film 106a and the conductive film 105b function as pixel electrodes. However, it is not limited to this.

More preferably, the conductive film 105b is used as a reflective conductive film to function as a reflective electrode, and the conductive film 106a is used as a transparent conductive film to function as a transparent electrode. The conductive film 106a is always arranged under the conductive film 105b, and the entire lower surface of the conductive film 105b is in contact with the upper surface of the conductive film 106a.

Then, the reflective electrode is arranged in the reflecting portion 108a, and the transparent electrode is arranged in the transmitting portion 108b. As a result, the reflective electrode and the transparent electrode can be manufactured with a small number of steps, and a semi-transmissive display device can be easily manufactured. Further, the reflective electrode and the transparent electrode do not require fine processing. Even if it is slightly off, there is no big problem. For example, even if the reflective electrode is a little small and the transparent electrode is large, the display is not significantly affected. Therefore, even if such a manufacturing method is performed, the manufacturing yield is unlikely to decrease. Therefore, it is beneficial for cost reduction and shortening of manufacturing days.

When a laminate of the conductive film 105b and the conductive film 106a is formed using the resist pattern 104a having regions having different film thicknesses of the present invention, when the conductive film 105b is formed, that is, when etching is performed using the resist pattern 104b as a mask. , Part of the surface of the conductive film 106a is slightly etched. In particular, when the conductive film 105b is formed by dry etching, it is difficult to obtain a selectivity with that of the lower conductive film 106a, so that a part of the surface of the conductive film 106a is more easily etched. Therefore, the film thickness a of the conductive film 106a in FIG. 2C (the film thickness of the conductive film 106a whose upper surface is in contact with the conductive film 105b) and the film thickness b (the film thickness of the portion whose upper surface is not in contact with the conductive film 105b) When comparing (the film thickness of 106a), the film thickness a &lt;the film thickness b. The film thickness a refers to the average film thickness of the conductive film 106a in the portion that does not overlap with the conductive film 105b, and the film thickness b refers to the average film thickness of the conductive film 106a in the portion that overlaps with the conductive film 105b.

The side surface of the conductive film 105b formed in the present embodiment may be inclined. Therefore, when used in a liquid crystal display device, if rubbing is performed from the inclined side surface side of the conductive film 105b, rubbing can be smoothly performed on the side surface of the conductive film 105b. When rubbing is performed from the direction in which the side surface of the conductive film 105b is vertical, the rubbing may be incomplete due to stress on the rubbing cloth at the vertical side surface portion, and the orientation may be incomplete. Therefore, it is preferable that the rubbing is performed from the side where the side surface of the conductive film 105b is inclined.

Further, when the conductive film 105b in which both side surfaces are inclined is formed by wet etching, rubbing can be smoothly performed from either direction, which is more effective.

As shown in FIGS. 1 (A) to 1 (B), a resist in which the resist in the portion irradiated with light dissolves is called a positive resist. However, the resist is not limited to the positive resist, and a negative resist may be used. In the negative resist, the resist in the portion not irradiated with light is dissolved.

FIG. 3 shows a diagram when a negative resist is used. FIG. 1 (A) corresponds to FIG. 3 (A), and FIG. 1 (B) corresponds to FIG. 3 (B). Other than that, there is almost no difference between the negative type and the positive type. As shown in FIG. 3 (A), the transparent portion 101c is arranged in the portion where the resist 304 is desired to be left, the light-shielding portion 101a is arranged in the portion where the resist 304 is to be removed, and the resist 304 is arranged in the portion where a small amount is desired to be left. Is arranged with a semipermeable membrane 101b. As a result, resist 304a is formed as shown in FIG. 3 (B).

Moreover, although it has been described using various figures in the present embodiment, one figure is composed of various constituent requirements. Therefore, it is possible to make a further configuration by combining each configuration requirement from each diagram.

(Embodiment 2) In the first embodiment, a case where a pixel electrode is formed on the insulating film 107 has been described. However, in reality, the pixel electrodes are connected to another wiring, a transistor, a holding capacitance, or the like. Therefore, if necessary, it is necessary to form a contact hole in the insulating film 107 and connect it to wiring or the like.

Therefore, a cross-sectional view in that case is shown in FIG. A contact hole 402 is formed in the insulating film 107a. Wiring 401 is formed under the contact hole 402. The wiring 401 is often connected to either the source or the drain of the transistor. Alternatively, the wiring 401 itself is often one of the source or drain of the transistor. In addition, it is often an electrode having a holding capacity.

At this time, the conductive film 106a is always arranged under the conductive film 105b. This is because the manufacturing method described in the first embodiment is used. Therefore, the conductive film 105b is also arranged on the conductive film 106a which is arranged so as to cover the contact hole 402.

Then, a transistor, wiring, and holding capacitance are formed under the conductive film 105b. When the conductive film 105b is a reflective electrode and the conductive film 106a is a transparent electrode, it is desirable to take as much transmission region as possible. This is to allow light to pass through it for display. On the other hand, in the reflection region, even if something is arranged under the reflection electrode, the display is not affected. Therefore, by arranging the transistor, the wiring, and the holding capacitance under the conductive film 105b, the layout can be efficiently performed.

It is desirable, but not limited to, that the entire area of the transistor and the holding capacitance is arranged under the reflective electrode. There is no problem even if a part of each of the transistor and the holding capacitance is arranged outside the reflecting electrode (outside the reflecting region).

Next, the unevenness of the reflective electrode will be described. The reflective electrode is for reflecting external light to perform display. In order to efficiently utilize the external light that has entered the reflective electrode and increase the display brightness, it is desirable that the reflective electrode diffusely reflect the external light.

Therefore, as shown in FIG. 5, the reflective electrode may be made uneven by providing the insulating film 107b with the unevenness 501. The insulating film 107b may have a laminated structure. Further, as shown in FIG. 6, the contact hole 501a may also be used as a means for forming unevenness. In this case, the contact hole 501a also has a function of connecting the wiring 401 and the conductive film 106a.

Next, an example of a method for forming the unevenness of the insulating film and the reflective electrode will be shown. In FIGS. 1 and 3, a method of forming a resist using an exposure mask having a light-shielding portion 101a through which the exposure light is shielded and a semipermeable membrane 101b through which the exposure light partially passes is described. Therefore, this manufacturing method may be applied to a method of forming the unevenness of the insulating film or the reflective electrode and the contact hole of the insulating film in a small number of steps. As a result, the number of steps can be further reduced.

Further, since this manufacturing method is used in the portion forming the transparent electrode and the reflecting electrode, the manufacturing equipment is in place. Therefore, even if this manufacturing method is used for forming the unevenness of the insulating film and the reflective electrode, there is nothing specially required. Therefore, there is a great merit in forming both of them by using this manufacturing method.

There is no problem even if the shape of this unevenness is slightly deviated. It is not a part where miniaturization is strongly required. Therefore, it can be manufactured without lowering the manufacturing yield.

In FIG. 7A, the exposure mask has a light-shielding portion 701a through which the exposure light is shielded, a semi-transparent portion 701b through which the exposure light partially passes, and a transparent portion 701c through which the exposure light passes. A semipermeable membrane 702 is provided on the semipermeable membrane 701b to reduce the light intensity of the exposure light. The light-shielding portion 701a is configured by laminating a metal film 703 on a semipermeable membrane 702. Here, an example in which a semipermeable membrane is used for the semipermeable membrane is shown, but the present invention is not limited to this, and the semipermeable membrane may be any one that reduces the light intensity of the exposure light. Further, a diffraction grating pattern may be used for the semipermeable membrane.

The electrode 705 is arranged on the insulating film 707. A film (for example, photosensitive acrylic) 704 that is sensitive to light is placed on it. When the film 704 is exposed using the exposure mask shown in FIG. 7 (A), a non-exposed region, an exposed region, and a semi-exposed region are formed. Then, the film 704 is removed from the portion exposed to the light. Then, as shown in FIG. 7B, the film 704a is formed, and the contact hole 706a and the unevenness 706 are formed at the same time.

In FIG. 7, irregularities are formed in addition to the contact holes, but the present invention is not limited to this. A plurality of holes such as contact holes may be formed, thereby forming irregularities. In that case, it is not necessary to provide wiring under the hole. This is because the purpose is not to make an electrical connection. However, if there is no electrical problem, wiring may be provided.

In FIG. 7, the film 704 in the portion exposed to light was removed, but the present invention is not limited to this. On the contrary, the film 704 in the portion not exposed to the light may be removed.

In FIG. 7, the resist was not used, but the present invention is not limited to this. After forming the film, dry etching or wet etching may be performed using a resist to form irregularities or contact holes.

In the transmission region, the thickness of the liquid crystal (cell gap) may be thicker than that in the reflection region. This is because light reciprocates in the reflection region, but only once in the transmission region. Therefore, the cell gap may be adjusted to increase the cell gap in the transmission region. The figure in that case is shown in FIG. By removing the membrane 704 to form the membrane 704b, not only the contact hole but also the recess 801 in the permeation region can be formed. The cell gap becomes thicker in the portion of the recess 801. Therefore, this portion may be set as a transparent region.

In this case, since it is not necessary to increase the number of special steps in order to increase the cell gap, the cost can be reduced.

It should be noted that this embodiment shows an example in which the content described in the first embodiment is partially modified. Therefore, the contents described in the first embodiment can be applied to the present embodiment and can be combined with the present embodiment.

Moreover, although it has been described using various figures in the present embodiment, one figure is composed of various constituent requirements. Therefore, it is possible to make a further configuration by combining each configuration requirement from each diagram.

(Embodiment 3) Next, a specific example when a transistor is arranged will be described. However, the transistor is not always necessary, and it may be applied to the so-called passive matrix type.

First, a method of forming a top-gate type TFT on the substrate 901 will be described with reference to FIG. The substrate 901 is a translucent substrate, for example, a quartz substrate, a glass substrate or a plastic substrate. The substrate 901 may be a light-shielding substrate, a semiconductor substrate, or an SOI (Silicon on Insulator) substrate.

An insulating film 902 is formed on the substrate 901 as a base film. The insulating film 902 includes a silicon oxide film, a silicon nitride film, or a silicon nitride film (SiO)._xN_y), Etc., or a laminate consisting of at least two films of these films is used.

It is better to use a silicon oxide film at the portion in contact with the semiconductor. As a result, electron trapping in the base film and hysteresis of transistor characteristics can be suppressed. In addition, it is desirable to arrange at least one film containing a large amount of nitrogen as the base film. Thereby, impurities from the glass can be reduced.

Next, an island-shaped semiconductor film 903 is formed on the insulating film 902.

The island-shaped semiconductor film 903 has a semiconductor film formed on the entire surface of the insulating film 902 by a sputtering method, an LPCVD method, a plasma CVD method, or the like, and then the semiconductor film is shaped by using a mask formed by a photolithography method or the like. To form. When forming the island-shaped semiconductor film 903 with a crystalline semiconductor film, a method of forming a crystalline semiconductor film directly on the substrate 901 and a method of forming an amorphous semiconductor film on the substrate 901 and then crystallizing by heat treatment. There is a method of forming a crystalline semiconductor film. In the latter method, the heat treatment at the time of crystallization is performed by using a heating furnace, laser irradiation, irradiation of light emitted from a lamp instead of laser light (hereinafter referred to as lamp annealing), or a combination thereof. Will be done.

Further, a crystalline semiconductor film may be formed by a thermal crystallization method in which nickel or the like is added to the amorphous semiconductor film and then the above heat treatment is performed. When a crystalline semiconductor film is obtained by crystallization using a thermal crystallization method using nickel, it is preferable to perform a gettering treatment for removing nickel after crystallization.

When a crystalline semiconductor film is produced by crystallizing by laser irradiation, a continuous-wave (CW) type laser beam or a pulse-oscillation type laser beam (pulse laser beam) can be used. The laser beams that can be used here are gas lasers such as Ar laser, Kr laser, excimer laser, single crystal YAG, and YVO.₄, Forsterite (Mg₂SiO₄), YAlO₃, GdVO₄Or polycrystalline (ceramic) YAG, Y₂O₃, YVO₄, YAlO₃, GdVO₄Lasers, glass lasers, ruby lasers, Alexandrite lasers, Ti: sapphire lasers whose medium is one or more of Nd, Yb, Cr, Ti, Ho, Er, Tm, and Ta added as dopants. , Copper vapor laser or gold vapor laser, which is oscillated from one or more kinds can be used. By irradiating the fundamental waves of such a laser beam and the laser beams of the second to fourth harmonics of these fundamental waves, crystals having a large particle size can be obtained. For example, Nd: YVO₄The second harmonic (532 nm) and the third harmonic (355 nm) of the laser (fundamental wave 1064 nm) can be used. This laser can be emitted by CW or by pulse oscillation. When emitting with CW, the power density of the laser is 0.01 ~ 100MW / cm²Degree (preferably 0.1-10 MW / cm²)is necessary. Then, the irradiation is performed with the scanning speed set to about 10 to 2000 cm / sec.

Single crystal YAG and YVO₄, Forsterite (Mg₂SiO₄), YAlO₃, GdVO₄Or polycrystalline (ceramic) YAG, Y₂O₃, YVO₄, YAlO₃, GdVO₄Lasers, Ar ion lasers, or Ti: sapphire lasers whose medium is one or more of Nd, Yb, Cr, Ti, Ho, Er, Tm, and Ta added as dopants are continuously oscillated. It is also possible to oscillate a pulse at an oscillation frequency of 10 MHz or higher by performing Q-switch operation or mode synchronization. When a laser beam is oscillated at an oscillation frequency of 10 MHz or higher, the next pulse is applied to the semiconductor film between the time when the semiconductor film is melted by the laser and the time when the semiconductor film is solidified. Therefore, unlike the case of using a pulse laser having a low oscillation frequency, the solid-liquid interface can be continuously moved in the semiconductor film, so that crystal grains continuously grown in the scanning direction can be obtained.

When ceramic (polycrystal) is used as the medium, it is possible to form the medium in a free shape in a short time and at low cost. When a single crystal is used, a columnar medium having a diameter of several mm and a length of several tens of mm is usually used, but when a ceramic is used, a larger medium can be produced.

Since the concentration of dopants such as Nd and Yb in the medium that directly contributes to light emission cannot be significantly changed in both single crystal and polycrystal, there is a certain limit to the improvement of laser output by increasing the concentration. However, in the case of ceramic, the size of the medium can be remarkably increased as compared with the single crystal, so that the output can be significantly improved.

Further, in the case of ceramics, it is possible to easily form a medium having a parallelepiped shape or a rectangular parallelepiped shape. When the oscillating light travels in a zigzag manner inside the medium using a medium having such a shape, the oscillating optical path can be lengthened. Therefore, the amplification becomes large, and it becomes possible to oscillate with a large output. Further, since the laser beam emitted from the medium having such a shape has a rectangular cross-sectional shape at the time of emission, it is advantageous to shape the laser beam into a linear beam as compared with a round beam. By shaping the laser beam emitted in this way using an optical system, it is possible to easily obtain a linear beam with a short side length of 1 mm or less and a long side length of several mm to several m. Become. Further, by uniformly irradiating the medium with the excitation light, the linear beam has a uniform energy distribution in the long side direction.

By irradiating the semiconductor film with this linear beam, it becomes possible to more uniformly anneal the entire surface of the semiconductor film. When uniform annealing is required to both ends of the linear beam, it is necessary to devise measures such as arranging slits at both ends to block the energy attenuation portion.

When a semiconductor film is annealed using a linear beam having a uniform intensity thus obtained and an electronic device is manufactured using the semiconductor film, the characteristics of the electronic device are good and uniform.

Then, if necessary, the semiconductor layer is doped with a trace amount of an impurity element (boron or phosphorus) to control the TFT threshold value. Here, diborane (B₂H₆) Is plasma-excited without mass separation. However, mass separation may be performed to accurately control the doping amount. As a result, the threshold voltage can be controlled accurately.

The island-shaped semiconductor film 903 is formed to have a thickness of 25 to 80 nm (preferably 30 to 70 nm). The material of the semiconductor film is not limited, but it is preferably formed of silicon, silicon germanium (SiGe) alloy, or the like.

Then, the gate insulating film 904 is formed so as to cover the island-shaped semiconductor film 903. As the gate insulating film 904, a single-layer or laminated structure such as a thermal oxide film, a silicon oxide film, a silicon nitride film, or a silicon oxide film can be used. A silicon oxide film is preferable as the gate insulating film in contact with the island-shaped semiconductor film 903. This is because the silicon oxide film reduces the trap level at the interface with the island-shaped semiconductor film. When the gate electrode is formed of Mo, the gate insulating film in contact with the gate electrode is preferably a silicon nitride film. This is because the silicon nitride film does not oxidize Mo.

Here, as the gate insulating film 904, a silicon oxide nitride film (composition ratio Si = 32%, O = 59%, N = 7%, H = 2%) having a thickness of 115 nm is formed by a plasma CVD method.

Next, a conductive layer is formed on the gate insulating film 904, and the conductive layer is shaped by using a mask formed by a photolithography method or the like to form a gate electrode 908 and a gate wiring. Wiring and electrodes for holding capacity may be formed. Materials for these conductive layers include Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, Au, Pt, Nb, Si, Zn, Fe, Ba, Ge, and alloys of these elements. is there. Alternatively, it may be composed of a laminate of these elements or an alloy of these elements. Here, the gate electrode is formed by Mo. Mo is suitable because it is easy to etch and is resistant to heat. Next, the island-shaped semiconductor film 903 is doped with an impurity element using the gate electrode 908 or the resist as a mask to form a channel forming region and an impurity region serving as a source region and a drain region.

At this time, an LDD region may be formed.

Then, it is insulated by using a translucent inorganic material (silicon oxide, silicon nitride, silicon oxide nitride, etc.), an organic compound material having a low dielectric constant (photosensitive or non-photosensitive organic resin material), or a laminate thereof. Form film 917. Further, the insulating film 917 (or a part thereof) may be formed by using a material containing siloxane. Siloxane is a material whose skeletal structure is composed of bonds of silicon (Si) and oxygen (O). As the substituent, an organic group containing at least hydrogen (for example, an alkyl group or an aromatic hydrocarbon) is used. A fluoro group may be used as the substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as the substituent. The insulating film 917 may have a laminated structure.

Next, a mask made of a resist is formed using a photomask, and the insulating film 917 and the gate insulating film 904 are selectively etched using the mask to form contact holes. Then, the mask made of resist is removed.

Then, a conductive film is formed on the insulating film 917 by a sputtering method, a printing method, a CVD method, or an inkjet method. Then, the conductive layer is shaped by using a mask formed by a photolithography method or the like to form a drain electrode 909, a source electrode, and a source wiring. Materials include Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, Au, Pt, Nb, Si, Zn, Fe, Ba, Ge, and alloys of these elements. Alternatively, the drain electrode 909 or the like may be formed by laminating these elements or alloys of these elements. Here, the drain electrode and the source wiring are formed by a three-layer structure in which the upper and lower sides of Al are sandwiched between Mo.

The drain electrode 909 corresponds to the wiring 401 in FIGS. 4 and 6, and the electrode 705 in FIGS. 7 and 8.

An insulating film 907 is formed on the insulating film 907. Since it is desirable that the insulating film 907 has good flatness and covering property, it is often formed by using an organic material. An organic material may be formed on an inorganic material (silicon oxide, silicon nitride, silicon nitriding, etc.) to form a multilayer structure. This insulating film 907 corresponds to the insulating film 107 in FIGS. 1 to 3 and the like.

Then, after forming a contact hole in the insulating film 907, a conductive film is formed on the insulating film 907 by a sputtering method, a printing method, a CVD method, or an inkjet method.

The conductive film 906 in FIG. 9 corresponds to the conductive film 106a in FIGS. 2 (C) and 4 to 6. The conductive film 905 in FIG. 9 corresponds to the conductive film 105b in FIGS. 2 (C) and 4 to 6.

The conductive film 906 is a part of a pixel electrode and is a transparent electrode that transmits light. The conductive film 905 is a part of the pixel electrode and is a reflective electrode that reflects light. The entire lower surface of the reflective electrode is in contact with the upper surface of the transparent electrode.

In the case of transparent electrodes, for example, indium tin oxide (ITO) film in which indium oxide is mixed with tin oxide, indium tin oxide (ITSO) film in which indium tin oxide (ITO) is mixed with silicon oxide, and indium oxide. An indium zinc oxide (IZO) film, a zinc oxide film, a tin oxide film, or the like in which zinc oxide is mixed with zinc oxide can be used. IZO is a transparent conductive material formed by sputtering using a target in which 2 to 20 wt% zinc oxide (ZnO) is mixed with ITO, but is not limited to this.

In the case of reflective electrodes, for example, Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, Au, Pt, Nb, Si, Zn, Fe, Ba, Ge, etc. and their alloys should be used. Can be done. Further, a two-layer structure in which Ti, Mo, Ta, Cr, W and Al are laminated, or a three-layer structure in which Al is sandwiched between metals such as Ti, Mo, Ta, Cr and W may be used.

The conductive film 905 and the conductive film 906 are formed by using the methods described in the first to second embodiments.

Although not shown, an alignment film is often formed on the conductive film 905 and the conductive film 906.

A color filter 916, a black matrix 915, a flattening film 912, a counter electrode 914, and the like are formed on the facing substrate 911. The liquid crystal layer 910 is arranged between the facing substrate 911 and the substrate 901.

In the portion (reflecting portion) 920 that reflects light for display, light passes through the liquid crystal layer 910 twice. That is, the external light enters the liquid crystal layer 910 from the opposite substrate side, is reflected by the conductive film 905, passes through the liquid crystal layer 910 again, and exits from the opposite substrate side, so that it passes through the liquid crystal layer 910 twice. become.

On the other hand, in the portion (transmissive portion) 921 that transmits light for display, the light enters the liquid crystal layer 910 through the conductive film 906 and exits from the opposite substrate. That is, light passes through the liquid crystal layer 910 once.

Here, since the liquid crystal layer 910 has refractive index anisotropy, the polarization state of light changes depending on the distance passing through the liquid crystal layer 910. Therefore, when the image is displayed, it cannot be displayed correctly. Therefore, it is necessary to adjust the polarization state of light. As a method for that, by reducing the thickness (so-called cell gap) of the liquid crystal layer 910 of the part (reflecting part) 920 that reflects light and displays it, the distance does not become too long even if it passes twice. It should be.

Therefore, in order to reduce the thickness of the liquid crystal layer 910 (so-called cell gap), a film for adjusting the thickness (also referred to as a film for adjusting the cell gap, a thickness adjusting film, a cell gap adjusting film, etc.) is arranged. do it. In FIG. 9, the insulating film 913 corresponds to this. That is, in the portion (reflecting portion) 920 that reflects light for display, the insulating film 913 is a layer provided for adjusting the thickness of the liquid crystal layer. By providing the insulating film 913, the thickness of the liquid crystal layer in the reflecting portion 920 can be made thinner than the thickness of the liquid crystal layer in the transmitting portion 921.

It is desirable that the thickness of the liquid crystal layer 910 at the reflecting portion 920 is half the thickness of the liquid crystal layer 910 at the transmitting portion 921. Here, the half includes the amount of deviation that may have a deviation that cannot be visually recognized by the human eye.

However, the light does not enter only in the direction perpendicular to the substrate, that is, in the normal direction. In many cases, it is incident from an angle. Therefore, in all of these cases, it is sufficient that the distance through which the light passes between the reflecting portion 920 and the transmitting portion 921 is substantially the same. Therefore, it is desirable that the thickness of the liquid crystal layer 910 at the reflecting portion 920 is approximately one-third or more and two-thirds or less of the thickness of the liquid crystal layer 910 at the transmitting portion 921.

By arranging the film for adjusting the thickness on the opposite substrate 911 side in this way, the formation becomes easy. The thickness-adjusting film is preferably formed using an organic material such as acrylic or polyimide.

Light scattering particles may be mixed in the film for adjusting the thickness. As a result, light can be scattered and the brightness can be improved. The light scattering particles are made of a material having a refractive index different from that of the cell gap adjusting film, and are made of a light-transmitting resin material. Such light scattering particles may be mixed with a film for adjusting the cell gap to produce the particles.

The counter electrode 914 is preferably located on the insulating film 913 (on the side closer to the liquid crystal layer 910). Thereby, a sufficiently large electric field can be applied to the liquid crystal layer 910.

However, it is not limited to this. As shown in FIG. 10, the insulating film 1013 may be arranged on the electrode 1014 (the side closer to the liquid crystal layer 910). Since the insulating film 1013 is very thick, it is possible to prevent the electrode 1014 from being disconnected.

In FIG. 9, the reflective electrode was not formed with irregularities in the reflecting portion 920, but irregularities may be formed as shown in FIGS. 5 and 6. The case is shown in FIG. The unevenness may be formed by using the method described in FIG. Light can be diffused by the unevenness 1001 and the contact hole 1001a.

In addition, in FIGS. 9 and 10, the thickness adjusting film is provided on the opposite substrate side, but the present invention is not limited to this. It may be arranged on the side where the transistor is formed. The case is shown in FIG. A part of the insulating film 907a is removed to form the insulating film 907a. In addition, FIG. 10 and FIG. 11 may be combined. An example of such a case is shown in FIG. The recess 1101 corresponds to the recess 801 in FIG. By providing the recess 801 in the transmitting portion 921 in this way, the cell gap of the transmitting portion 921 can be made larger than the cell gap of the reflecting portion 920.

Both the recess and the thickness adjusting film may be provided. Since the thickness may be controlled by both, the thickness of one does not have to be very large. Therefore, it becomes easy to manufacture.

In FIG. 11, the recess 1101 is formed by removing a part of the insulating film 907a, but the recess 1101 is not limited to this. Other insulating films may also be removed. For example, FIG. 50 shows a case where not only the insulating film 907a but also a part of the insulating film 917a is removed. As a result, it becomes easy to make a difference in cell gap between the reflecting portion 920 and the transmitting portion 921. Further, the thickness of the insulating film 907a can be reduced as compared with the case where only the insulating film 907a is removed. Therefore, defects such as warpage of the substrate can be reduced.

FIG. 51 further shows a case where the insulating film 902e, the gate insulating film 904e, the substrate 901e, and the like are partially removed. Since the insulating film 902e, the gate insulating film 904e, the substrate 901e, and the like may be formed of films having similar components, the recess 1101c can be formed deeper.

The unevenness may be formed by using a contact hole. The case is shown in FIG. A contact hole 1301 is provided in a place where the conductive film 906 is not connected to the drain electrode 909, and the contact hole 1301 is used to form unevenness. In this way, a plurality of contact holes 1301 are formed not for connecting the wiring to each other but for making the surface of the wiring and the electrode uneven. In the contact hole 1301, the conductive film 906 may be connected to the drain electrode 909 in the same manner as in the contact hole 1001a.

Further, FIG. 14 shows a case where the recess 1101 is provided in the case of FIG.

As described above, there are a plurality of methods for each of the presence / absence of unevenness, the method of forming the unevenness, the method of adjusting the cell gap (whether the thickness adjustment is performed on the facing substrate side or the TFT substrate side), and the like. Therefore, one of them may be selected and combined.

When the conductive film 905 is a reflective electrode, it is desirable that a transistor, wiring, and holding capacitance are formed beneath the reflective electrode. When the conductive film 905 is a reflective electrode and the conductive film 906 is a transparent electrode, it is desirable to take as much transmission region as possible. This is to allow light to pass through it for display. On the other hand, in the reflection region, even if something is arranged under the reflection electrode, the display is not affected. Therefore, by arranging the transistor, the wiring, and the holding capacity under the conductive film 905, the layout can be efficiently performed.

It is desirable, but not limited to, that the entire area of the transistor and the holding capacitance is arranged under the reflective electrode. There is no problem even if a part of each of the transistor and the holding capacitance is arranged outside the reflecting electrode (outside the reflecting region).

Therefore, FIGS. 47 and 48 show cross-sectional views when a transistor and a holding capacitance are arranged under the reflecting electrode. In FIG. 47, a part of the semiconductor layer used as the active layer in the transistor 4702 is used to form one of the electrodes having a holding capacity of 4701. In FIG. 47, the holding capacity 4701 is formed between the island-shaped semiconductor film 903 and the holding capacity wiring 908e by using the gate insulating film 904 as an insulator. Further, a part of the drain electrode 909 is used to form a holding capacity 4701 even with the holding capacity wiring 908e by using the insulating film 917 as an insulator. In FIG. 48, a holding capacitance 4801 is formed between the semiconductor layer 903f, which is different from the semiconductor layer used as the active layer in the transistor 4702, and the holding capacitance wiring 908f, using the gate insulating film 904 as an insulator. The semiconductor layer 903f is connected to the drain electrode 909 via a contact hole.

In FIGS. 9 to 14 and 47 to 48, an insulating film is provided on the drain electrode, but the present invention is not limited to this. The drain electrode 905a may be used as a reflective electrode, the transparent electrode 906a may be arranged under the drain electrode, and the pixel electrode may be arranged on the insulating film 1517 above the gate electrode. A cross-sectional view in that case is shown in FIG. Also in the case of FIG. 15, the surface of the reflective electrode may be made uneven, or a thickness adjusting film or a concave portion may be formed in order to adjust the cell gap. As an example, FIG. 16 shows a case where the unevenness of the reflective electrode is formed by using the contact holes 1601 and 1601a.

In addition, in FIGS. 9 to 16 and 47 to 48, the case of a so-called top gate type transistor in which the gate electrode is arranged on the channel has been described, but the present invention is not limited to this. It can also be applied to a so-called bottom gate type transistor in which a gate electrode is arranged below the channel.

The case of the bottom gate type transistor is shown in FIG. A gate insulating film 1704 is formed on the gate electrode 1708. An island-shaped semiconductor film 1703 is formed on the island. An insulating film 1717 is formed on the insulating film 1717. Then, a contact hole is formed, and a drain electrode 1709 and a source signal line are formed on the contact hole. Above the drain electrode 1709 and the source signal line is the same as in the case of the top gate structure. Therefore, even in the case of the bottom gate type, the surface of the reflective electrode may be made uneven, or a thickness adjusting film or a concave portion may be formed in order to adjust the cell gap. Further, the unevenness of the reflective electrode may be formed by using the contact hole.

It should be noted that this embodiment shows an example in which the contents described in the first and second embodiments are realized more concretely. Therefore, the contents described in the first and second embodiments can be applied to the present embodiment and can be combined with the present embodiment.

Moreover, although it has been described using various figures in the present embodiment, one figure is composed of various constituent requirements. Therefore, it is possible to make a further configuration by combining each configuration requirement from each diagram.

(Embodiment 4) Various types of liquid crystal molecules can be arranged on the liquid crystal layer 910.

For example, a TN (Twisted Nematic) type liquid crystal can be mentioned. When a TN type liquid crystal is used, it is not necessary to provide a slit in the pixel electrode. That is, it suffices if they are arranged on one surface within one pixel. Further, the common electrode formed on the facing substrate may be formed on one surface over all the pixels. Therefore, the pixel electrodes (transparent electrode, reflective electrode) as described in the first to third embodiments may be used.

Liquid crystals other than the TN type include an MVA (Multi-domain Vertical Alignment) method in which liquid crystal molecules are arranged in the vertical direction and a PVA (Patterned Vertical Alignment) method. In the case of the MVA method or the PVA method, in order to control the inclination of the liquid crystal molecules, slits are made in the pixel electrodes or the pixel electrodes are divided and arranged at intervals. Alternatively, a protrusion is provided.

Therefore, FIG. 18 shows a cross-sectional view of the case where the pixel electrode has a slit. As shown in FIG. 18, the PVA method has slits and the like in the counter electrode, and as shown in FIG. 19, the facing electrode is provided with protrusions 1901, 1902, which is the MVA. It is a method.

When the manufacturing method of the present invention is used, the side surface of the conductive layer 906b and the side surface of the conductive layer 905b are not aligned. The side surface of the conductive layer 905b has a recessed shape. The entire lower surface of the reflective electrode is in contact with the upper surface of the transparent electrode. This is due to the manufacturing method of the present invention, such as the resist shape when etching each conductive layer.

By using the MVA method or PVA method, the viewing angle characteristics are improved. Therefore, the visibility is improved, and an image with reduced color unevenness can be displayed from any angle. Moreover, since the normally black method can be used, the brightness in the black state can be made very small. Therefore, the contrast ratio can be increased.

It should be noted that this embodiment shows an example in which the contents described in the first to third embodiments are realized more concretely and a certain part is explained in more detail. Therefore, the contents described in the first to third embodiments may be applied to the present embodiment or may be combined with the present embodiment.

Moreover, although it has been described using various figures in the present embodiment, one figure is composed of various constituent requirements. Therefore, it is possible to make a further configuration by combining each configuration requirement from each diagram.

(Embodiment 5) Next, the case of a transistor using amorphous silicon will be described. For the types of substrates constituting the TFT described in the present embodiment, the method for forming each layer, the materials, and the like, the first to fourth embodiments can be referred to.

Even in the case of a transistor using amorphous silicon, a bottom gate type (reverse stagger type), a top gate type (normal stagger type), and the like can be realized. Here, the case where a transistor in the case of the inverted stagger type is used will be described.

FIG. 21 shows a cross-sectional view. An insulating film is formed on the substrate 2101 as a base film. The base film may not be provided. Next, the conductive layer is formed on the insulating film or the substrate 2101, and the conductive layer is shaped by using a mask formed by a photolithography method or the like to form the gate electrode 2108 and the gate wiring. Wiring and electrodes for holding capacity may be formed.

A gate insulating film 2104 is formed so as to cover the gate electrode 2108. As the gate insulating film 2104, a silicon nitride film, a silicon oxide film, or a laminate thereof is used. An amorphous semiconductor film is formed on the gate insulating film 2104. The material of the amorphous semiconductor film is not limited, but it is preferably formed of silicon, silicon germanium (SiGe) alloy, or the like. Subsequently, a conductive layer is formed on the amorphous semiconductor film. For the conductive layer, for example, an amorphous silicon film containing phosphorus can be used. Then, using a mask formed by a photolithography method or the like, the shapes of the amorphous semiconductor film and the conductive layer are processed to form the amorphous semiconductor film and the conductive layer in an island shape. Usually, these layers are silicon-based semiconductor layers 2103.

A conductive layer is laminated and formed on the semiconductor layer 2103, and the conductive layer is shaped by using a mask formed by a photolithography method or the like to form a drain electrode 2109.

Then, the conductive layer of the semiconductor layer 2103 is etched using the drain electrode 2109 or the like as a mask. This separates the source and drain. Such a configuration is usually referred to as a channel etch type.

The drain electrode 2109 corresponds to the wiring 401 in FIGS. 4 and 6, and the electrode 705 in FIGS. 7 and 8.

An insulating film 2102 is formed on the insulating film 2102. The insulating film 2102 is preferably a silicon nitride film. This is to prevent various impurities from entering the transistor. A silicon oxide film or a laminated film containing the same may be used.

Next, the insulating film 2107 is formed to absorb the unevenness of the wiring and flatten it. For this, an organic film such as acrylic or polyimide is used. It may be a photosensitive material.

The insulating film 2107 and the insulating film 2102 correspond to the insulating film 107 in FIGS. 1 to 3 and the like.

Next, contact holes are formed in the insulating film 2102 and the insulating film 2107. Then, a conductive film is formed on the conductive film.

The electrode 2106 in FIG. 21 corresponds to the conductive film 106a in FIGS. 2 (C) and 4 to 6. The electrode 2105 in FIG. 21 corresponds to the conductive film 105b in FIGS. 2 (C) and 4 to 6.

Electrode 2106 is a part of a pixel electrode and is a transparent electrode that transmits light. The electrode 2105 is a part of the pixel electrode and is a reflective electrode that reflects light. The entire lower surface of the reflective electrode is in contact with the upper surface of the transparent electrode.

In the case of transparent electrodes, for example, indium tin oxide (ITO) film in which indium oxide is mixed with tin oxide, indium tin oxide (ITSO) film in which indium tin oxide (ITO) is mixed with silicon oxide, and indium oxide. An indium zinc oxide (IZO) film, a zinc oxide film, a tin oxide film, or the like in which zinc oxide is mixed with zinc oxide can be used. IZO is a transparent conductive material formed by sputtering using a target in which 2 to 20 wt% zinc oxide (ZnO) is mixed with ITO, but is not limited to this.

In the case of reflective electrodes, for example, Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, Au, Pt, Nb, Si, Zn, Fe, Ba, Ge, etc. and their alloys should be used. Can be done. Further, a two-layer structure in which Ti, Mo, Ta, Cr, W and Al are laminated, or a three-layer structure in which Al is sandwiched between metals such as Ti, Mo, Ta, Cr and W may be used.

The conductive film 2105 and the conductive film 2106 are formed by using the methods described in the first to second embodiments.

Although not shown, an alignment film is often formed on the conductive film 2105 and the conductive film 2106.

The matters related to the counter electrode 2114, the insulating film 2113, the flattening film 2112, the black matrix 2115, the color filter 2116, the counter substrate 2111, and the liquid crystal layer 2110 are the same as those described in the first to fourth embodiments. However, it will be described as an example.

In FIG. 21, the reflective electrode was not formed with irregularities in the reflecting portion 920, but irregularities may be formed as shown in FIGS. 5 and 6. The case is shown in FIG. The unevenness may be formed by using the method described in FIG. Light can be diffused by the unevenness 2201 and the contact hole 2201a.

Light scattering particles may be mixed in the films 2113 and 2213 for adjusting the thickness. As a result, light can be scattered and the brightness can be improved. Let me. The light scattering particles are made of a material having a refractive index different from that of the cell gap adjusting film, and are made of a light-transmitting resin material. Such light scattering particles may be mixed with a film for adjusting the cell gap to produce the particles.

In addition, in FIG. 21 and FIG. 22, the thickness adjusting film is provided on the opposite substrate side, but the present invention is not limited to this. It may be arranged on the side where the transistor is formed. The case is shown in FIG. In addition, FIG. 21 and FIG. 22 may be combined. An example of such a case is shown in FIG. The recess 2301 corresponds to the recess 801 in FIG. By providing the recess 2301 in the transmitting portion 921 in this way, the cell gap of the transmitting portion 921 can be made larger than the cell gap of the reflecting portion 920.

In FIG. 23, the recess 2301 is formed by removing a part of the insulating film 2107a, but the recess 2301 is not limited to this. Other insulating films may also be removed. For example, not only the insulating film 2107a but also a part of the insulating film 2102 may be removed. FIG. 52 further shows a case where the gate insulating film 2104e, the substrate 2101e, and the like are partially removed. As a result, it becomes easy to make a difference in cell gap between the reflecting portion 920 and the transmitting portion 921. Further, since the insulating film 2102e, the gate insulating film 2104e, the substrate 2101e, and the like may be formed of films having similar components, the recess 2301e can be formed deeper.

In FIG. 24, both the recess and the thickness adjusting film are provided, but the present invention is not limited to this. Only one of them may be used. However, if both are provided, the thickness of one does not have to be very large because the thickness can be controlled by both. Therefore, it becomes easy to manufacture.

The unevenness may be formed by using a contact hole. The case is shown in FIG. A contact hole 2501 is provided in a place where the electrode 2106 is not connected to the drain electrode 2109, and the contact hole 2501 is used to form unevenness. In this way, a plurality of contact holes 2501 are formed not for connecting the wiring to each other but for making the surface of the wiring and the electrode uneven. In the contact hole 2501, the electrode 2106 may be connected to the drain electrode 2109 in the same manner as the contact hole 2201a.

In the case of FIG. 25, the recess 2301 may be provided.

In FIGS. 21 to 25, channel-etched transistors are used, but the present invention is not limited to this. It may be channel protected. As an example, in the case of FIG. 21, a cross-sectional view when a channel-protected transistor is used is shown in FIG. A channel protection film 2601 is placed on the semiconductor layer 2603a forming a channel, and a phosphorus-containing semiconductor layer and a conductive layer (drain electrode, source signal line, etc.) 2603b are arranged on the channel protection film 2601. The cases of FIGS. 22 to 25 and 49 can also be applied to the channel protection type transistor in the same manner.

The TFT having the channel protection film 2601 has the following effects. Since there is no concern that the semiconductor layer is etched, the semiconductor layer 2603a can be formed thinly, and the characteristics of the TFT can be improved. Therefore, a large current can be passed through the TFT, and the signal writing time can be shortened, which is preferable.

In FIGS. 21 to 26 and 49, the insulating film 2107 is provided on the insulating film 2102, but the present invention is not limited to this. It is also feasible when there is no need to flatten. A cross-sectional view in that case is shown in FIG. 27. By omitting the insulating film 2107, the number of processes can be reduced and the cost can be reduced. Also in the case of FIG. 27, the surface of the reflective electrode may be made uneven, a thickness adjusting film or a concave portion may be formed to adjust the cell gap, or the reflective electrode may be formed by using a contact hole. Concavities and convexities may be formed.

In this way, there are a plurality of methods for the presence / absence of unevenness, the method for forming the unevenness, the method for adjusting the cell gap (whether the thickness is adjusted on the opposite substrate side or the TFT substrate side), the transistor structure, and the like. .. Therefore, one of them may be selected and combined.

It should be noted that this embodiment shows an example in which the contents described in the first to fourth embodiments are realized more concretely and a certain part is explained in more detail. Therefore, the contents described in the first to fourth embodiments can be applied to and combined with the present embodiment.

Moreover, although it has been described using various figures in the present embodiment, one figure is composed of various constituent requirements. Therefore, it is possible to make a further configuration by combining each configuration requirement from each diagram.

(Embodiment 6) Up to now, the cross-sectional view has been mainly used, but in the present embodiment, the top view will be described.

FIG. 28 shows a top view when applicable to FIGS. 9 and 47. FIG. 28 shows one pixel (one color element). A semiconductor layer 2803a is formed, and a gate wiring 2808a and a capacitance line 2808b are formed on the semiconductor layer 2803a. A transistor is formed by a gate electrode formed on the semiconductor layer 2803a, which is a continuous film with the gate wiring 2808a. A semiconductor layer 2803a is arranged below the capacitance line 2808b, and the capacitance line 2808b and the semiconductor layer 2803a form a holding capacitance. A capacitance is formed by the upper and lower electrodes via the gate insulating film. In that case, the semiconductor layer 2803a in the region to be the electrode of the capacitance may or may not be attached with phosphorus or boron. If not attached, the capacitance line 2808b is supplied with a high voltage. When phosphorus or boron is attached, the capacitance line 2808b is often electrically connected to the counter electrode. As a result, the number of wires can be reduced.

A source signal line 2809a and a drain electrode 2809b are formed on the source signal line 2809a. They are connected to the semiconductor layer 2803a via a contact hole.

The drain electrode 2809b may be arranged large so that the region overlapping the capacitance line 2808b is large so that the capacitance value of the holding capacitance can be increased.

A transparent electrode 2806 is formed on the transparent electrode 2806, and is connected to the drain electrode 2809b via a contact hole. A reflective electrode 2803b is formed on the reflective electrode 2803b.

The reflective electrode 2803b is formed on the transistor and the holding capacitance. As a result, the aperture ratio in the transmissive portion can be improved, and the layout can be performed efficiently.

In addition, although the capacitance line 2808b is arranged, it is not limited to this. Instead of the capacitance line 2808b, the gate signal line one line before may be used. That is, the gate signal line one line before can function as a holding capacitance line because the potential is constant in the non-selected state.

In FIG. 28, the holding capacitance was arranged in the vicinity of the transistor, but in FIG. 29, it was arranged in the central portion of the pixel electrode. As a result, a plurality of transparent portions can be provided in one pixel. Therefore, it is possible to have a plurality of regions having different orientation states of the liquid crystal molecules, and it is possible to easily form a multi-domain structure. The multi-domain structure can widen the viewing angle.

FIG. 30 shows a case where the unevenness 3001 is formed on the reflective electrode as compared with the case of FIG. 27. This corresponds to FIGS. 10 and 13. By forming irregularities on the reflective electrode, light is diffused and the brightness can be increased.

Similarly, FIG. 31 shows a case where the unevenness 3001 is formed on the reflective electrode as opposed to the case where the holding capacitance is arranged in the central portion of the pixel electrode as in the case of FIG. 29. By forming irregularities on the reflective electrode, light is diffused and the brightness can be increased. Further, since a plurality of transmissive portions can be provided in one pixel, a plurality of regions having different orientation states of the liquid crystal molecules can exist, and a multi-domain structure can be easily formed. When the multi-domain structure is used, it is possible to prevent the amount of light transmitted from being reduced when viewed at a specific angle, and it is possible to widen the viewing angle.

Next, as shown in FIG. 11, the case where the recess 3201 is formed is shown in FIG. As a result, the cell gap can be made different between the reflective portion and the transmissive portion, so that visibility is improved and an image with reduced color unevenness can be displayed with correct gradation. Further, since the cell gap can be adjusted at the same time on the substrate on the side where the transistors, capacitances, wirings, etc. are arranged, the number of steps is small and the cost can be reduced.

Similarly, FIG. 33 shows a case where the recesses 3201a and 3201b are formed as opposed to the case where the holding capacitance is arranged in the central portion of the pixel electrode as in the case of FIG. 29.

28 to 33 show a case where the pixel electrodes are arranged on one surface for each pixel. This mainly corresponds to the case of using a TN type liquid crystal.

However, as shown in FIGS. 18 and 19, it is possible to make slits in the pixel electrodes, and it is also possible to divide the pixel electrodes and arrange them at intervals.

FIG. 34 shows a top view when the pixel electrodes are slit or the pixel electrodes are divided and arranged at intervals to correspond to the MVA type, the PVA type, or the like. Slits 3401a, 3401b, 3401c, 3401d and the like are formed in both the transmission region and the reflection region. This by Re, it is possible to determine the direction in which the tilt of the liquid crystal molecules.

Further, by arranging the holding capacitance portion under the reflecting portion, the aperture ratio of the transmitting portion can be improved, and the optimum layout can be performed.

Further, by arranging the reflecting portion and the holding capacitance in the central portion of the pixel electrode and arranging the transmitting portions above and below the reflecting portion, a plurality of transmitting portions can be provided in one pixel, so that the orientation state of the liquid crystal molecules can be changed. Multiple different regions can exist, making it easier to create a multi-domain structure. As a result, it is possible to prevent the amount of light transmitted from being reduced when viewed at a specific angle, and it is possible to improve the viewing angle.

FIG. 35 shows a case where unevenness 3001 is formed in the reflecting portion. By forming irregularities on the reflective electrode, light is diffused and the brightness can be increased.

As described above, the configuration in which the pixel electrodes are slit or the pixel electrodes are divided and arranged at intervals can be applied to FIGS. 28 to 33.

The method of inserting the slits is not limited to those in FIGS. 34 and 35, and various arrangements can be made.

In FIGS. 28 to 35, an example in the case of using a transistor having a top gate structure is shown. However, the present invention is not limited to this, and configurations other than these are also possible. Next, an example in the case of using a transistor having an inverted stagger structure will be shown.

FIG. 36 corresponds to FIG. 21. Gate wiring 3608a and capacitance line 3608b are formed. A semiconductor layer 3603 is formed on the semiconductor layer 3603. A transistor is composed of a gate electrode formed under the semiconductor layer 3603, which is a continuous film with the gate wiring 3608a. A source signal line 3609a and a drain electrode 3619b are formed on the source signal line 3609a. A drain electrode 3619b is arranged on the capacitance line 3608b, where a holding capacitance is formed. A capacitance is formed by the upper and lower electrodes via the gate insulating film. A transparent electrode 3606 is formed on the transparent electrode 3606, and is connected to the drain electrode 3619b via a contact hole. A reflective electrode 3605 is formed on the reflective electrode 3605.

The reflective electrode 3605 is formed on the transistor and the holding capacitance. As a result, the aperture ratio in the transmissive portion can be improved, and the layout can be performed efficiently.

In FIG. 36, the holding capacitance is arranged in the vicinity of the transistor, but it may be arranged in the central portion of the pixel electrode. As a result, since a plurality of transmissive portions can be provided in one pixel, a plurality of regions having different orientation states of the liquid crystal molecules can exist, and a multi-domain structure can be easily formed. When the multi-domain structure is used, it is possible to prevent the amount of light transmitted from being reduced when viewed at a specific angle, and it is possible to widen the viewing angle.

FIG. 37 shows a case where unevenness 3701 is formed on the reflective electrode as opposed to the case of FIG. 36. This corresponds to FIGS. 22 and 25. By forming irregularities on the reflective electrode, light is diffused and the brightness can be increased.

Next, as shown in FIG. 23, the case where the recess 3801 is formed is shown in FIG. 38. As a result, the cell gap can be made different between the reflective portion and the transmissive portion, so that visibility is improved and an image with reduced color unevenness can be displayed with correct gradation.

In FIGS. 36 to 38, the case where the pixel electrodes are arranged on one surface for each pixel is described. This mainly corresponds to the case of using a TN type liquid crystal.

However, as shown in FIGS. 18 and 19, it is possible to make slits in the pixel electrodes, and it is also possible to divide the pixel electrodes and arrange them at intervals.

FIG. 39 shows a top view when the pixel electrodes are slit or the pixel electrodes are divided and arranged at intervals to correspond to the MVA type, the PVA type, or the like. Slits 3901a, 3901b, 3901c, 3901d and the like are formed in both the transmission region and the reflection region. This makes it possible to determine the tilting direction of the liquid crystal molecules.

Further, by arranging the holding capacitance portion under the reflecting portion, the aperture ratio of the transmitting portion can be improved, and the optimum layout can be performed.

Further, by arranging the reflecting portion and the holding capacitance in the central portion of the pixel electrode and arranging the transmitting portions above and below the reflecting portion, it is possible to facilitate the multi-domain structure. As a result, it is possible to prevent the amount of light transmitted from being reduced when viewed at a specific angle, and it is possible to improve the viewing angle.

In addition, unevenness may be formed in the reflective portion (above the reflective electrode 3605a).

The slit in FIG. 39 has a wavy shape. This makes it easier to control the liquid crystal molecules.

In this way, the configuration in which the pixel electrodes are slit or the pixel electrodes are divided and arranged at intervals can be applied to other top views.

The method of inserting the slit is not limited to FIG. 39, and various arrangements can be made.

It should be noted that this embodiment shows an example in which the contents described in the first to fifth embodiments are realized more concretely and a certain part is explained in more detail. Therefore, the contents described in the first to fifth embodiments can be applied to the present embodiment and can be combined with the present embodiment.

Moreover, although it has been described using various figures in the present embodiment, one figure is composed of various constituent requirements. Therefore, it is possible to make a further configuration by combining each configuration requirement from each diagram.

(Embodiment 7) In the present embodiment, the exposure masks used in the first to sixth embodiments will be described with reference to FIG. 20 (A) to 20 (C) show top views of the light-shielding portion 101a and the semipermeable membrane 101b of the exposure mask shown in FIGS. 1, 3, 7, and 8. The width of the light-shielding portion 101a of the exposure mask is shown as t1, and the width of the semipermeable membrane portion 101b is shown as t2.

A diffraction grating pattern can be provided on the semipermeable membrane 101b, and FIGS. 20 (A) and 20 (B) show a diffraction grating pattern having slits made up of a plurality of slits below the resolution limit of the exposure apparatus. There is. The diffraction grating pattern is a pattern in which at least one or more patterns such as slits and dots are arranged. When a plurality of patterns such as slits and dots are arranged, they may be arranged periodically or aperiodically. By using a fine pattern below the resolution limit, it is possible to modulate the actual exposure amount, and it is possible to adjust the film thickness of the exposed resist after development.

The direction in which the slit of the slit portion extends may be parallel to one side of the light-shielding portion 303 as in the slit portion 301, or perpendicular to one side of the light-shielding portion 303 as in the slit portion 302. Alternatively, the diagonal direction with respect to one side of the light-shielding portion 303 may be the direction in which the slit extends. The resist used in this photolithography step is preferably a positive resist.

Further, as another example of the semipermeable membrane, FIG. 20C shows an example in which a semipermeable membrane 2004 having a function of reducing the light intensity of the exposure light is provided. As the semipermeable membrane, MoSi, MoSiO, MoSiON, CrSi and the like can be used in addition to MoSiN. An exposure method using an exposure mask provided with a semipermeable membrane is also called a halftone exposure method.

When the exposure masks shown in FIGS. 20 (A) to 20 (C) are irradiated with the exposure light, the light intensity of the light-shielding portion 303 is zero and the light intensity of the light-transmitting portion 305 is 100%. On the other hand, the intensity of light passing through the semipermeable membranes 301, 302 or the semipermeable membrane 2004 having the light intensity reducing function can be adjusted in the range of 10 to 70%. An example of a typical light intensity distribution is shown in Fig. 20 (D). When the semipermeable membrane has a diffraction grating pattern, the light intensity passing through the semipermeable membrane is adjusted by adjusting the pitch and the slit width of the slit portions 301 and 302.

Further, the present embodiment can be freely combined with the first to sixth embodiments.

(Embodiment 8) The pixel circuit of the present invention will be described. In the pixel array 50000 in FIG. 45, the pixels 50001 are arranged in a matrix. A source signal line 50002 to which a video signal is input and a gate signal line 50003 to which a gate signal is input are connected to the pixel 50001. The transistor 50004 is controlled by using those signals, and the liquid crystal C_LC, Input the video signal to the holding capacity Cs. The holding capacity Cs is connected to the holding capacity line 50005. Then, depending on the video signal, the liquid crystal C_LCThe light transmittance of is changed and the image is displayed.

As shown in FIG. 46, at least a pixel array 50000 is arranged on the glass substrate 60000. Then, a gate signal line drive circuit 60001 for driving the gate signal line and a source signal line drive circuit 60002 for supplying a video signal to the source signal line may be arranged. In some cases, both are arranged, and in other cases, only one of them is arranged.

The source signal line drive circuit 6602 includes, but is not limited to, a shift register, a sampling switch, a latch circuit, a DA converter circuit, and the like. In some cases, only the sampling switch is arranged and the shift register and the like are not arranged.

It should be noted that this embodiment shows an example in which the contents described in the first to seventh embodiments are realized more concretely and a certain part is explained in more detail. Therefore, the contents described in the first to seventh embodiments can be applied to the present embodiment and can be combined with the present embodiment.

Moreover, although it has been described using various figures in the present embodiment, one figure is composed of various constituent requirements. Therefore, it is possible to make a further configuration by combining each configuration requirement from each diagram.

(Embodiment 9) A configuration example of a mobile phone having the display device of the present invention in the display unit will be described with reference to FIG. 40.

The display panel 5410 is detachably integrated into the housing 5400. The shape and dimensions of the housing 5400 can be appropriately changed according to the size of the display panel 5410. The housing 5400 to which the display panel 5410 is fixed is fitted into the printed circuit board 5401 and assembled as a module.

The display panel 5410 is connected to the printed circuit board 5401 via the FPC 5411. A signal processing circuit 5405 including a speaker 5402, a microphone 5403, a transmission / reception circuit 5404, a CPU, a controller, and the like is formed on the printed circuit board 5401. Such a module is combined with the input means 5406 and the battery 5407, and housed in the housings 5409 and 5412. The pixel portion of the display panel 5410 is arranged so that it can be visually recognized from the opening window formed in the housing 5412.

In the display panel 5410, a pixel portion and a part of peripheral drive circuits (a drive circuit having a low operating frequency among a plurality of drive circuits) are integrally formed on a substrate by using TFT, and a part of the peripheral drive circuits (a plurality of drives) are integrally formed. A drive circuit having a high operating frequency among the circuits) may be formed on an IC chip, and the IC chip may be mounted on the display panel 5410 by COG (Chip On Glass). Alternatively, the IC chip may be connected to a glass substrate using a TAB (Tape Auto Bonding) or a printed circuit board. An example of the configuration of the display panel in which a part of the peripheral drive circuits are integrally formed with the pixel portion on the substrate and the IC chip on which the other peripheral drive circuits are formed is mounted by COG or the like is shown in FIG. 41 (a). is there. With such a configuration, it is possible to reduce the power consumption of the display device and prolong the usage time by charging the mobile phone once. In addition, the cost of the mobile phone can be reduced.

Further, by impedance-converting the signal set in the scanning line or the signal line by the buffer, the writing time of the pixel for each line can be shortened. Therefore, a high-definition display device can be provided.

In order to further reduce power consumption, a pixel part is formed on the substrate using TFT, all peripheral drive circuits are formed on an IC chip, and the IC chip is used as a display panel with COG (Chip On Glass) or the like. It may be implemented.

Then, by using the display device of the present invention, it is possible to view an image with high contrast.

Further, the configuration shown in this embodiment is an example of a mobile phone, and the display device of the present invention can be applied not only to a mobile phone having such a configuration but also to a mobile phone having various configurations.

The contents described in the present embodiment can be freely combined with the contents described in the first to eighth embodiments.

Moreover, although it has been described using various figures in the present embodiment, one figure is composed of various constituent requirements. Therefore, it is possible to make a further configuration by combining each configuration requirement from each diagram.

(Embodiment 10) FIG. 42 shows a liquid crystal module in which a display panel 5701 and a circuit board 5702 are combined. The display panel 5701 has a pixel unit 5703, a scanning line driving circuit 5704, and a signal line driving circuit 5705. For example, a control circuit 5706 and a signal division circuit 5707 are formed on the circuit board 5702. The display panel 5701 and the circuit board 5702 are connected by the connection wiring 5708. FPC or the like can be used for the connection wiring.

In the display panel 5701, a pixel portion and a part of peripheral drive circuits (a drive circuit having a low operating frequency among a plurality of drive circuits) are integrally formed on a substrate by using TFT, and a part of the peripheral drive circuits (a plurality of drives) are integrally formed. Of the circuits, a drive circuit with a high operating frequency) should be formed on an IC chip, and the IC chip should be mounted on the display panel 5701 with COG (Chip On Glass) or the like. Alternatively, the IC chip may be mounted on the display panel 5701 using a TAB (Tape Auto Bonding) or a printed circuit board. An example of a configuration in which a part of the peripheral drive circuits are integrally formed with the pixel portion on the substrate and an IC chip on which the other peripheral drive circuits are formed is mounted by COG or the like is shown in FIG. 41 (a). With such a configuration, it is possible to reduce the power consumption of the display device and prolong the usage time by charging the mobile phone once. In addition, the cost of the mobile phone can be reduced.

By impedance-converting the signals set in the scanning lines and signal lines with a buffer, the writing time of pixels for each line can be shortened. Therefore, a high-definition display device can be provided.

In order to further reduce power consumption, a pixel part is formed on a glass substrate using TFT, all signal line drive circuits are formed on an IC chip, and the IC chip is used as a COG (Chip On Glass) display panel. It may be implemented.

It is preferable to form a pixel portion on a substrate using a TFT, form all peripheral drive circuits on an IC chip, and mount the IC chip on a display panel with COG (Chip On Glass). An example of a configuration in which an IC chip in which a pixel portion is formed on a substrate and a signal line drive circuit is formed on the substrate is mounted by COG or the like is shown in FIG. 41 (b).

With this liquid crystal module, a liquid crystal television receiver can be completed. FIG. 43 is a block diagram showing a main configuration of the liquid crystal television receiver. Tuner 5801 receives video and audio signals. The video signal is the video signal amplifier circuit 5802, the video signal processing circuit 5803 that converts the signal output from it into a color signal corresponding to each color of red, green, and blue, and the video signal to the input specifications of the drive circuit. It is processed by the control circuit 5706 for conversion. The control circuit 5706 outputs signals to the scanning line side and the signal line side, respectively. In the case of digital driving, a signal dividing circuit 5707 may be provided on the signal line side, and the input digital signal may be divided into m pieces and supplied.

Of the signals received by the tuner 5801, the audio signal is sent to the audio signal amplifier circuit 5804, and the output is supplied to the speaker 5806 via the audio signal processing circuit 5805. The control circuit 5807 receives control information of the receiving station (reception frequency) and volume from the input unit 5808, and sends a signal to the tuner 5801 and the audio signal processing circuit 5805.

A television receiver can be completed by incorporating the liquid crystal module into the housing. The liquid crystal module forms a display unit. In addition, speakers, video input terminals, etc. are appropriately provided.

Of course, the present invention is not limited to television receivers, and is applied to various applications such as personal computer monitors, information display boards at railway stations and airports, and advertisement display boards on the streets. can do.

As described above, by using the display device of the present invention, it is possible to view an image with high contrast.

The contents described in the present embodiment can be freely combined with the contents described in the first to ninth embodiments.

Moreover, although it has been described using various figures in the present embodiment, one figure is composed of various constituent requirements. Therefore, it is possible to make a further configuration by combining each configuration requirement from each diagram.

(Embodiment 11) The present invention can be applied to various electronic devices. Specifically, it can be applied to the display unit of an electronic device. Such electronic devices include video cameras, digital cameras, goggle-type displays, navigation systems, sound playback devices (car audio, audio components, etc.), computers, game devices, mobile information terminals (mobile computers, mobile phones, portable games, etc.). Machines or electronic books, etc.), image playback devices equipped with recording media (specifically, devices equipped with display devices that can play back recording media such as Digital Versatile Disc (DVD) and display the images), etc. Be done.

FIG. 44A is a display device, which includes a housing 35001, a support base 35002, a display unit 35003, a speaker unit 35004, a video input terminal 35005, and the like. The display device of the present invention can be used for the display unit 35003. The display device includes all information display devices for personal computers, television broadcast reception, advertisement display, and the like. A display device using the display device of the present invention for the display unit 35003 can be viewed as a high-contrast image.

FIG. 44B is a camera, which includes a main body 35101, a display unit 35102, an image receiving unit 35103, an operation key 35104, an external connection port 35105, a shutter 35106, and the like.

A digital camera using the present invention for the display unit 35102 enables viewing with a high-contrast image.

FIG. 44C shows a computer, which includes a main body 35201, a housing 35202, a display unit 35203, a keyboard 35204, an external connection port 35205, a pointing device 35206, and the like. A computer using the present invention for the display unit 35203 can be viewed as a high-contrast image.

FIG. 44 (D) is a mobile computer, which includes a main body 35301, a display unit 35302, a switch 35303, an operation key 35304, an infrared port 35305, and the like. A mobile computer using the present invention for the display unit 35302 can be viewed as a high-contrast image.

FIG. 44 (E) shows a portable image playback device (specifically, a DVD playback device) equipped with a recording medium, which includes a main body 35401, a housing 35402, a display unit A35403, a display unit B35404, and a recording medium (DVD, etc.). Includes reading unit 35405, operation key 35406, speaker unit 35407, etc. The display unit A35403 can mainly display image information, and the display unit B35404 can mainly display character information. An image reproduction device using the present invention for the display unit A35403 and the display unit B35404 can be viewed as a high-contrast image.

FIG. 44 (F) is a goggle-type display, which includes a main body 35501, a display unit 35502, and an arm unit 35503. A goggle-type display using the present invention for the display unit 35502 can be viewed as a high-contrast image.

FIG. 44 (G) shows a video camera, which is a main body 35601, a display unit 35602, a housing 35603, an external connection port 35604, a remote control receiver 35605, an image receiver 35606, a battery 35607, an audio input unit 35608, an operation key 35609, and an eyepiece. Includes part 35610 and so on. A video camera using the present invention for the display unit 35602 can view an image with high contrast.

FIG. 44 (H) is a mobile phone, which includes a main body 35701, a housing 35702, a display unit 35703, a voice input unit 35704, a voice output unit 35705, an operation key 35706, an external connection port 35707, an antenna 35708, and the like. A mobile phone using the present invention for the display unit 35703 can be viewed with a high-contrast image.

As described above, the scope of application of the present invention is extremely wide, and it can be used in electronic devices in all fields. Further, as the electronic device of the present embodiment, a display device having any configuration shown in the first to thirteenth embodiments may be used.

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the semiconductor device of this invention.</figref><figref num="19">The cross-sectional view which shows the semiconductor device of this invention.</figref><figref num="20">The top view of the exposure mask of the present invention and the figure which shows the light intensity distribution.</figref><figref num="21">The cross-sectional view which shows the semiconductor device of this invention.</figref><figref num="22">The cross-sectional view which shows the semiconductor device of this invention.</figref><figref num="23">The cross-sectional view which shows the semiconductor device of this invention.</figref><figref num="24">The cross-sectional view which shows the semiconductor device of this invention.</figref><figref num="25">The cross-sectional view which shows the semiconductor device of this invention.</figref><figref num="26">The cross-sectional view which shows the semiconductor device of this invention.</figref><figref num="27">The cross-sectional view which shows the semiconductor device of this invention.</figref><figref num="28">Top view of the semiconductor device of the present invention.</figref><figref num="29">Top view of the semiconductor device of the present invention.</figref><figref num="30">Top view of the semiconductor device of the present invention.</figref><figref num="31">Top view of the semiconductor device of the present invention.</figref><figref num="32">Top view of the semiconductor device of the present invention.</figref><figref num="33">Top view of the semiconductor device of the present invention.</figref><figref num="34">Top view of the semiconductor device of the present invention.</figref><figref num="35">Top view of the semiconductor device of the present invention.</figref><figref num="36">Top view of the semiconductor device of the present invention.</figref><figref num="37">Top view of the semiconductor device of the present invention.</figref><figref num="38">Top view of the semiconductor device of the present invention.</figref><figref num="39">Top view of the semiconductor device of the present invention.</figref><figref num="40">The figure explaining one aspect of the electronic device to which this invention was applied.</figref><figref num="41">The figure which shows the semiconductor device of this invention.</figref><figref num="42">The figure which shows the semiconductor device of this invention.</figref><figref num="43">The figure which shows the semiconductor device of this invention.</figref><figref num="44">The figure explaining one aspect of the electronic device to which this invention was applied.</figref><figref num="45">The circuit diagram of the liquid crystal display device of this invention.</figref><figref num="46">The block diagram of the circuit structure of the liquid crystal display device of this invention.</figref><figref num="47">The cross-sectional view which shows the semiconductor device of this invention.</figref><figref num="48">The cross-sectional view which shows the semiconductor device of this invention.</figref><figref num="49">The cross-sectional view which shows the semiconductor device of this invention.</figref><figref num="50">The cross-sectional view which shows the semiconductor device of this invention.</figref><figref num="51">The cross-sectional view which shows the semiconductor device of this invention.</figref><figref num="52">The cross-sectional view which shows the semiconductor device of this invention.</figref>