3-group nitride semiconductor
Abstract
This record has no abstract on file.
Term
Term ended
Expired 10 March 2017, 9.5 years ago.
- Priority
- Filed
- Granted
- Expired
- Today
3 claims: 2 independent, 1 dependent
- 1【特許請求の範囲】 【請求項1】 n伝導型を示す3族窒化物半導体(Al X1 Ga Y1 In 1-X1-Y1 N;0≦X1≦1, 0≦Y1≦1, 0≦X1+Y1 ≦1)から成るn層と、p伝導型を示す3族窒化物半導体(Al X2 Ga Y2 In 1-X2-Y2 N;0≦X2≦1, 0≦Y2≦1, 0≦X2+Y2 ≦1)から成るp層と、その間に介在する3族窒化物半導体(Al X3 Ga Y3 In 1-X3-Y3 N;0≦X3≦1, 0≦Y3≦1, 0≦X3+Y3 ≦1)から成る発光層がヘテロ接合で形成された3層構造を有する発光素子において、 前記p層に対するニッケル(Ni)から成る電極を有し、 前記発光層には、ドナー不純物とアクセプタ不純物とが添加されていることを特徴とする3族窒化物半導体発光素子。
- 2【請求項2】 n伝導型を示す3族窒化物半導体(Al X1 Ga Y1 In 1-X1-Y1 N;0 ≦X1≦1, 0≦Y1≦1, 0≦X1+Y1 ≦1)から成るn層と、p伝導型を示す3族窒化物半導体(Al X2 Ga Y2 In 1-X2-Y2 N;0≦X2≦1, 0≦Y2≦1, 0≦X2+Y2 ≦1)から成るp層と、その間に介在する3族窒化物半導体(Al X3 Ga Y3 In 1-X3-Y3 N;0≦X3≦1, 0≦Y3≦1, 0≦X3+Y3 ≦1)から成る発光層がヘテロ接合で形成された3層構造を有する発光素子において、 前記発光層は窒化ガリウム(GaN) 又はアルミニウムを含む3族窒化物半導体(Al x3 Ga Y3 In 1-X3-Y3 N;0 X3≦1, 0≦Y3≦1, 0≦X3+Y3 ≦1)から成り、ドナー不純物とアクセプタ不純物とが添加されており、 前記p層に対するニッケル(Ni)から成る電極を有していることを特徴とする3族窒化物半導体発光素子。
- 3【請求項3】前記p層と前記電極との間にp-GaN から成るコンタクト層が形成されていることを特徴とする請求項1又は請求項2に記載の3族窒化物半導体発光素子。
Independent claims3
138 paragraphs in 1 section, as filed
Description: TECHNICAL FIELD [Detailed description of the invention]
【0001】
[Industrial application field]
The present invention relates to a light emitting device using a group 3 nitride semiconductor.
【0002】
[Previous technology]
Conventionally, one using an AlGaInN-based compound semiconductor as a blue light emitting diode is known. Since the compound semiconductor is a direct transition type, it is attracting attention because it has high luminous efficiency and blue, which is one of the three primary colors of light, is used as the luminous color.
【0003】
Recently, it has become clear that even AlGaInN-based semiconductors can be converted to p-type by doping with Mg and irradiating with an electron beam or by heat treatment. As a result, instead of the conventional MIS type in which the n layer and the semi-insulating layer (i layer) are joined, a double using an AlGaN p layer, a Zn-doped GaInN light emitting layer, and an AlGaN n layer. Light emitting diodes with hetero-pn junctions have been proposed.
【0004】
[Problems to be Solved by the Invention]
In the above double hetero pn junction type light emitting diode, the light emitting layer is doped with Zn as a light emitting center. Although this type of light emitting diode has considerably improved light emitting intensity, further improvement in light emitting intensity is desired. As described above, in the conventional light emitting device, only magnesium (Mg) or zinc (Zn) acceptor impurities are added to the light emitting layer. For this reason, the light emitting mechanism of this device is due to the transition between the conduction band and the acceptor level, but due to the large energy level difference, non-luminescent recombination via other deep levels occurs. The emission intensity is not high because it is dominant. The emission peak wavelength is 380 to 440 nm, which is slightly shorter than that of pure blue. The present invention has been made to solve the above problems, and an object of the present invention is to improve the emission intensity of a light emitting device using an AlGaInN semiconductor and to obtain a spectrum closer to pure blue.
【0005】
【0006】
[Means for solving problems]
The invention of claim 1 is a group 3 nitride semiconductor (Al) exhibiting an n-conduction type.<sub>X1</sub>Ga<sub>Y1</sub>In<sub>1-X1-Y1</sub>N; n-layer consisting of 0 X1 1, 0 Y1 1, 0 X1 + Y1 1) and group 3 nitride semiconductor (Al) showing p-conduction type<sub>X2</sub>Ga<sub>Y2</sub>In<sub>1-X2-Y2</sub>N; 0 X2 1, 0 Y2 1, 0 X2 + Y2 1) and the group 3 nitride semiconductor (Al) intervening between them.<sub>X3</sub>Ga<sub>Y3</sub>In<sub>1-X3-Y3</sub>N; 0 X3 1, 0 Y3 1, 0 X3 + Y3 1) In a light emitting element having a three-layer structure in which a light emitting layer is formed by a heterojunction, from nickel (Ni) with respect to the p layer. The light emitting layer is characterized in that a donor impurity and an acceptor impurity are added.
【0007】
The invention of claim 2 is a group 3 nitride semiconductor (Al) exhibiting an n-conduction type.<sub>X1</sub>Ga<sub>Y1</sub>In<sub>1-X1-Y1</sub>N-layer consisting of N; 0 X1 1, 0 Y1 1, 0 X1 + Y1 1) and group 3 nitride semiconductor (Al) showing p-conduction type<sub>X2</sub>Ga<sub>Y2</sub>In<sub>1-X2-Y2</sub>N; 0 X2 1, 0 Y2 1, 0 X2 + Y2 1) and the group 3 nitride semiconductor (Al) intervening between them.<sub>X3</sub>Ga<sub>Y3</sub>In<sub>1-X3-Y3</sub>N; 0 X3 1, 0 Y3 1, 0 X3 + Y3 1) In a light emitting device having a three-layer structure in which a light emitting layer is formed by a heterojunction, the light emitting layer is gallium nitride (GaN). Or a group 3 nitride semiconductor containing aluminum (Al<sub>x3</sub>Ga<sub>Y3</sub>In<sub>1-X3-Y3</sub>N; 0 <X3 1, 0 Y3 1, 0 X3 + Y3 1), donor impurities and acceptor impurities are added, and it has an electrode composed of nickel (Ni) for the p layer. It is characterized by being.
【0008】
The invention of claim 3 is characterized in that, in claims 1 and 2, a contact layer made of p-GaN is formed between the p layer and the electrode.
【0009】
INDUSTRIAL APPLICABILITY
As described above, since the donor impurity and the acceptor impurity are mixed in the light emitting layer, the light emitting mechanism recombines the electron at the donor level and the hole at the acceptor level, and the light emitting intensity is increased. Further, the recombination between the electron at the donor level and the hole at the acceptor level also occurs inside the light emitting layer, and as a result, the light emission intensity is also improved.
【0010】
[Example]
First Example In FIG. 1, the light emitting diode 10 has a sapphire substrate 1, and a buffer layer 2 of AlN of 500 Å is formed on the sapphire substrate 1. On the buffer layer 2, in order, the film thickness is about 2.0 μm and the electron concentration is 2 × 10.<sup>18</sup>/cm<sup>3</sup>High carrier concentration n consisting of silicon-doped GaN<sup>+ </sup>Layer 3, film thickness about 2.0 μm, electron concentration 2 × 10<sup>18</sup>/cm<sup>3</sup>Silicon-doped (Al<sub>x2</sub>Ga<sub>1-x2</sub>)<sub>y2</sub>In<sub>1-y2</sub>High carrier concentration n consisting of N<sup>+ </sup>Layer 4, film thickness about 0.5 μm, cadmium (Cd) and silicon-doped (Al<sub>x1</sub>Ga<sub>1-x1</sub>)<sub>y1</sub>In<sub>1-y1</sub>I layer (light emitting layer) consisting of N 5, film thickness about 1.0 μm, hole concentration 2 × 10<sup>17</sup>/cm<sup>3</sup>Magnesium-doped (Al<sub>x2</sub>Ga<sub>1-x2</sub>)<sub>y2</sub>In<sub>1-y2</sub>A p-layer 6 consisting of N is formed. Then, the electrode 7 made of nickel connected to the p layer 6 and the high carrier concentration n<sup>+ </sup>An electrode 8 made of nickel connected to layer 4 is formed. The electrode 7 and the electrode 8 are electrically insulated and separated by a groove 9.
【0011】
Next, a method of manufacturing the light emitting diode 10 having this structure will be described. The light emitting diode 10 was manufactured by vapor phase growth by an organometallic compound vapor phase growth method (hereinafter referred to as "M0VPE"). The gas used was NH<sub>3</sub> And carrier gas H<sub>2</sub>Or N<sub>2</sub> And trimethylgallium (Ga (CH)<sub>3</sub>)<sub>3</sub>) (Hereinafter referred to as "TMG") and trimethylaluminum (Al (CH)<sub>3</sub>)<sub>3</sub>) (Hereinafter referred to as "TMA") and trimethylindium (In (CH)<sub>3</sub>)<sub>3</sub>) (Hereinafter referred to as "TMI") and dimethylcadmium (Cd (CH)<sub>3</sub>)<sub>2</sub>) (Hereinafter referred to as "DMCd") and silane (SiH)<sub>4</sub>) And cyclopentadienyl magnesium (Mg (C)<sub>5</sub>H<sub>5</sub>)<sub>2</sub>) (Hereafter "CP"<sub>2</sub>It is written as "Mg").
【0012】
First, the single crystal sapphire substrate 1 having the a-plane main surface cleaned by organic cleaning and heat treatment is mounted on a susceptor placed in the reaction chamber of the M0VPE apparatus. Next, H at normal pressure<sub>2</sub>The sapphire substrate 1 was vapor-phase etched at a temperature of 1100 ° C.
【0013】
Then lower the temperature to 400 ° C and H<sub>2</sub>20 liters / minute, NH<sub>3</sub> 10 liters / minute, TMA 1.8 x 10<sup>-5</sup>Feeding at mol / min, buffer layer 2 of AlN was formed to a thickness of about 500 Å. Next, the temperature of the sapphire substrate 1 was maintained at 1150 ° C, the film thickness was about 2.2 μm, and the electron concentration was 2 × 10.<sup>18</sup>/cm<sup>3</sup>High carrier concentration n consisting of silicon-doped GaN<sup>+ </sup>Layer 3 was formed.
【0014】
Hereinafter, examples of the composition ratios and crystal growth conditions of the light emitting layer 5 (active layer) and the clad layers 4 and 6 when the emission peak wavelength is set to 430 nm with cadmium (Cd) and silicon (Si) as the emission center are described. .. The above high carrier concentration n<sup>+ </sup>After forming layer 3, the temperature of sapphire substrate 1 was subsequently maintained at 850 ° C and N.<sub>2</sub>Or H<sub>2</sub>10 liters / minute, NH<sub>3</sub> 10liter / min, TMG 1.12 × 10<sup>-4</sup>Mol / min, TMA 0.47 x 10<sup>-4</sup>Mol / min, TMI 0.1 x 10<sup>-4</sup>Introduced mol / min and silane, film thickness about 0.5 μm, concentration 1 × 10<sup>18</sup>/cm<sup>3</sup>Silicon-doped (Al<sub>0.47</sub>Ga<sub>0.53</sub>)<sub>0.9</sub>In<sub>0.1</sub>High carrier concentration n consisting of N<sup>+ </sup>Layer 4 was formed.
【0015】
Then keep the temperature at 850 ° C and N<sub>2</sub>Or H<sub>2</sub>20 liters / minute, NH<sub>3</sub> 10liter / min, TMG 1.53 × 10<sup>-4</sup>Mol / min, TMA 0.47 x 10<sup>-4</sup>Mol / min, TMI 0.02 x 10<sup>-4</sup>Mol / min and DMCd 2 x 10<sup>-7</sup>10 x 10 mol / min and silane<sup>-9</sup>Introduced in mol / min, cadmium (Cd) and silicon (Si) -doped (Al) with a film thickness of about 0.5 μm.<sub>0.3</sub>Ga<sub>0.7</sub>)<sub>0.94</sub>In<sub>0.06</sub>A light emitting layer 5 composed of N was formed. The light emitting layer 5 is a high resistance layer. The concentration of cadmium (Cd) in this light emitting layer 5 is 5 × 10.<sup>18</sup>/cm<sup>3</sup>And the concentration of silicon (Si) is 1 x 10<sup>18</sup>/cm<sup>3</sup>Is.
【0016】
Then keep the temperature at 1100 ° C and N<sub>2</sub>Or H<sub>2</sub>20 liters / minute, NH<sub>3</sub> 10liter / min, TMG 1.12 × 10<sup>-4</sup>Mol / min, TMA 0.47 x 10<sup>-4</sup>Mol / min, TMI 0.1 x 10<sup>-4</sup>Mol / min and CP<sub>2</sub>Mg 2 x 10<sup>-4</sup>Introduced in mol / min and magnesium (Mg) -doped (Al) with a film thickness of about 1.0 μm.<sub>0.47</sub>Ga<sub>0.53</sub>)<sub>0.9</sub>In<sub>0.1</sub>A p-layer 6 consisting of N was formed. Magnesium concentration in layer 6 is 1 x 10<sup>20</sup>/cm<sup>3</sup>Is. In this state, layer 6 still has a resistivity of 10.<sup>8</sup> It is an insulator of Ω cm or more.
【0017】
Next, the p layer 6 was uniformly irradiated with an electron beam using a reflected electron beam diffractometer. The electron beam irradiation conditions are an acceleration voltage of about 10 KV, a reference current of 1 μA, a beam moving speed of 0.2 mm / sec, a beam diameter of 60 μmφ, and a vacuum degree of 5.0 × 10.<sup>-5</sup>Torr. By irradiation with this electron beam, the p-layer 6 has a hole concentration of 2 × 10.<sup>17</sup>/cm<sup>3</sup>, It became a p-conducting semiconductor with a resistivity of 2Ωcm. In this way, a wafer having a multilayer structure as shown in FIG. 2 was obtained.
【0018】
3 to 7 described below are cross-sectional views showing only one element on the wafer. In reality, a wafer in which this element is continuously repeated is processed, and then each element is processed. Be disconnected.
【0019】
As shown in FIG. 3, SiO was sputtered onto the p-layer 6.<sub>2</sub>Layer 11 was formed to a thickness of 2000 Å. Then that SiO<sub>2</sub>The photoresist 12 was applied onto the layer 11. Then, by photolithography, the high carrier concentration n on the p layer 6<sup>+ </sup>The photoresist of the electrode forming portion A corresponding to the hole 15 formed to reach the layer 4 and the part B forming the groove 9 for insulatingly separating the electrode forming portion from the electrode of the p layer 6 was removed.
【0020】
Next, as shown in FIG. 4, SiO not covered by photoresist 12<sub>2</sub>Layer 11 was removed with a hydrofluoric acid-based etching solution. Next, as shown in FIG. 5, photoresist 12 and SiO<sub>2</sub>P layer 6 in the part not covered by layer 11 and the light emitting layer 5 below it, high carrier concentration n<sup>+ </sup>Part of the upper surface of layer 4 has a vacuum degree of 0.04 Torr and high frequency power of 0.44 W / cm.<sup>2</sup> , BCl<sub>3</sub>Gas was supplied at a rate of 10 ml / min and dry etching was performed, and then dry etching was performed with Ar. In this process, high carrier concentration n<sup>+ </sup>A hole 15 for taking out the electrode for the layer 4 and a groove 9 for insulating separation were formed.
【0021】
Next, as shown in FIG. 6, SiO remaining on the p layer 6<sub>2</sub>Layer 11 was removed with hydrofluoric acid. Next, as shown in FIG. 7, a Ni layer 13 was formed by vapor deposition on the entire upper surface of the sample. As a result, the hole 15 has a high carrier concentration n.<sup>+ </sup>A Ni layer 13 electrically connected to the layer 4 is formed. Then, as shown in FIG. 7, the photoresist 14 is applied on the Ni layer 13, and the photoresist 14 has a high carrier concentration n by a photolithography.<sup>+ </sup>A pattern was formed in a predetermined shape so that the electrode portions for the layer 4 and the p layer 6 remained.
【0022】
Next, as shown in FIG. 7, the exposed portion of the lower Ni layer 13 was etched with a nitric acid-based etching solution using the photoresist 14 as a mask. At this time, the Ni layer 13 deposited in the groove 9 for insulation separation is completely removed. Next, the photoresist 14 was removed with acetone to achieve a high carrier concentration n.<sup>+ </sup>The electrode 8 of the layer 4 and the electrode 7 of the p layer 6 were left. Then, the wafer processed as described above was cut for each element to obtain a gallium nitride based light emitting element having a pn structure shown in FIG.
【0023】
The light emitting device thus obtained had a drive current of 20 mA, a light emission peak wavelength of 430 nm, and a light emission intensity of 100 mcd.
【0024】
The concentrations of cadmium (Cd) and silicon (Si) mentioned above are 1 × 10, respectively.<sup>17</sup>~1×10<sup>20</sup>The range of is desirable in that it improves the emission intensity. Further, it is more desirable that the concentration of silicon (Si) is about 1/2 to 1/10 less than that of cadmium (Cd).
【0025】
In the above embodiment, the p layer 6 in which the band gap of the light emitting layer 5 is present on both sides and the high carrier concentration n<sup>+ </sup>It is formed in a double heterojunction that is smaller than the band gap of layer 4. The component ratios of Al, Ga, and In in these three layers are the high carrier concentration n of GaN.<sup>+ </sup>Selected to match the lattice constant of the layer. Further, although the double heterojunction structure is used in the above embodiment, a single heterojunction structure may be used.
【0026】
Second Example Cadmium (Cd) and silicon (Si) are added to the light emitting layer 5 of the first example, but zinc (Zn) and silicon (Zn) and silicon are added to the light emitting layer 5 of the second example as shown in FIG. (Si) is added. The above high carrier concentration n<sup>+ </sup>After forming layer 3, the temperature of sapphire substrate 1 was subsequently maintained at 800 ° C and N.<sub>2</sub>20 liters / minute, NH<sub>3</sub> 10liter / min, TMG 1.12 × 10<sup>-4</sup>Mol / min, TMA 0.47 x 10<sup>-4</sup>Mol / min, TMI 0.1 x 10<sup>-4</sup>Introduced mol / min and silane, film thickness about 0.5 μm, concentration 2 × 10<sup>19</sup>/cm<sup>3</sup>Silicon-doped (Al<sub>0.3</sub>Ga<sub>0.7</sub>)<sub>0.94</sub>In<sub>0.06</sub>High carrier concentration n consisting of N<sup>+ </sup>Layer 4 was formed.
【0027】
Then keep the temperature at 1150 ° C and N<sub>2</sub>20 liters / minute, NH<sub>3</sub> 10liter / min, TMG 1.53 × 10<sup>-4</sup>Mol / min, TMA 0.47 x 10<sup>-4</sup>Mol / min, TMI 0.02 x 10<sup>-4</sup>Mol / min, 10 x 10 silanes<sup>-9</sup>Mol / min, DEZ 2 x 10<sup>-4</sup>Introduced at mol / min for 7 minutes and doped with silicon (Si) and zinc (Zn) with a film thickness of about 0.5 μm (Al).<sub>0.09</sub>Ga<sub>0.91</sub>)<sub>0.99</sub>In<sub>0.01</sub>A light emitting layer 5 composed of N was formed. The concentration of zinc (Zn) in this light emitting layer 5 is 2 × 10.<sup>18</sup>/cm<sup>3</sup>And the concentration of silicon (Si) is 1 x 10<sup>18</sup>/cm<sup>3</sup>Is.
【0028】
Then keep the temperature at 1100 ° C and N<sub>2</sub>20 liters / minute, NH<sub>3</sub> 10liter / min, TMG 1.12 × 10<sup>-4</sup>Mol / min, TMA 0.47 x 10<sup>-4</sup>Mol / min, TMI 0.1 x 10<sup>-4</sup>Mol / min and CP<sub>2</sub>Mg 2 x 10<sup>-4</sup>Introduced in mol / min and magnesium (Mg) -doped (Al) with a film thickness of about 1.0 μm.<sub>0.3</sub>Ga<sub>0.7</sub>)<sub>0.94</sub>In<sub>0.06</sub>A p-layer 6 consisting of N was formed. Magnesium concentration in layer 6 is 1 x 10<sup>20</sup>/cm<sup>3</sup>Is. In this state, layer 6 still has a resistivity of 10.<sup>8</sup> It is an insulator of Ω cm or more.
【0029】
Next, the p layer 6 was uniformly irradiated with an electron beam using a reflected electron beam diffractometer. The electron beam irradiation conditions are the same as those in the first embodiment. Hereinafter, the light emitting diode 10 was formed by the same manufacturing method as in the first embodiment. The emission peak wavelength of the light emitting diode 10 is 430 nm, and the emission intensity is 1000 mcd.
【0030】
Third Example The light emitting diode of the third embodiment has the configuration shown in FIG. 9, and is formed by further adding magnesium (Mg) to the light emitting layer 5 of the light emitting diode of the second embodiment and irradiating it with an electron beam to form a p-type. .. The formation of the other layers except the light emitting layer 5 is the same as that of the second embodiment. Further, the light emitting layer 5 is CP in the manufacturing process of the light emitting diode of the second embodiment.<sub>2</sub>Mg 2 x 10<sup>-7</sup>The only difference is the addition of more at a ratio of mol / minute.
【0031】
Doped with magnesium (Mg), zinc (Zn) and silicon (Si) with a film thickness of about 0.5 μm (Al)<sub>0.09</sub>Ga<sub>0.91</sub>)<sub>0.99</sub>In<sub>0.01</sub>A light emitting layer 5 composed of N was formed. The light emitting layer 5 is still in this state and has a resistivity of 10<sup>8</sup> It is an insulator of Ω cm or more. The concentration of magnesium (Mg) in this light emitting layer 5 is 1 × 10.<sup>19</sup>/cm<sup>3</sup>And the concentration of zinc (Zn) is 2 x 10<sup>18</sup>/cm<sup>3</sup>And the concentration of silicon (Si) is 1 x 10<sup>18</sup>/cm<sup>3</sup>Is.
【0032】
Then, the light emitting layer 5 and the p layer 6 are uniformly irradiated with the electron beam by using the reflected electron beam diffractometer. The electron beam irradiation conditions are the same as those in the first embodiment. By irradiating this electron beam, the light emitting layer 5 and the p layer 6 have a hole concentration of 2 × 10.<sup>17</sup>/cm<sup>3</sup>, It became a p-conducting semiconductor with a resistivity of 2Ωcm.
【0033】
Fourth Example In the light emitting diode of the fourth embodiment, the light emitting layer 5 is made of GaN and is a single heterojunction. That is, one of the junctions has a high concentration n of GaN with a high concentration of silicon (Si) added.<sup>+ </sup>Layer 4 is a GaN light emitting layer 5 to which zinc (Zn) and silicon (Si) are added, and the other junction is a GaN light emitting layer 5 and magnesium (Mg) added p-conducting Al.<sub>0.1</sub>Ga<sub>0.9</sub>It is a junction with p-layer 61 consisting of N. In this embodiment, a contact layer 62 made of p-conducting GaN to which magnesium (Mg) is added is formed on the p-layer 61. Further, the groove 9 for insulation separation is formed through the contact layer 62, the p layer 61, and the light emitting layer 5.
【0034】
In FIG. 10, the light emitting diode 10 has a sapphire substrate 1, and a buffer layer 2 of AlN of 500 Å is formed on the sapphire substrate 1. On the buffer layer 2, in order, the film thickness is about 4.0 μm and the electron concentration is 2 × 10.<sup>18</sup>/cm<sup>3</sup>High carrier concentration n consisting of silicon-doped GaN<sup>+ </sup>Layer 4, film thickness about 0.5 μm, light emitting layer 5 made of zinc and silicon-doped GaN, film thickness about 0.5 μm, hole concentration 2 × 10<sup>17</sup>/cm<sup>3</sup>Magnesium-doped Al<sub>0.1</sub>Ga<sub>0.9</sub>P layer 61 consisting of N, film thickness about 0.5 μm, hole concentration 2 × 10<sup>17</sup>/cm<sup>3</sup>A contact layer 62 made of magnesium-doped GaN is formed. Then, the electrode 7 made of nickel connected to the contact layer 62 and the high carrier concentration n<sup>+ </sup>An electrode 8 made of nickel connected to layer 4 is formed. The electrode 7 and the electrode 8 are electrically insulated and separated by a groove 9.
【0035】
Next, a method of manufacturing the light emitting diode 10 having this structure will be described. As in the first embodiment, the buffer layer 2 of AlN is formed. Next, the temperature of the sapphire substrate 1 was maintained at 1150 ° C, the film thickness was about 4.0 μm, and the electron concentration was 2 × 10.<sup>18</sup>/cm<sup>3</sup>High carrier concentration n consisting of silicon-doped GaN<sup>+ </sup>Layer 4 was formed.
【0036】
Hereinafter, examples of composition ratios and crystal growth conditions of the light emitting layer 5, the clad layer, that is, the p layer 61, and the contact layer 62 when the emission peak wavelength is set to 430 nm with zinc (Zn) and silicon (Si) as the emission centers I will write it. The above high carrier concentration n<sup>+ </sup>After forming layer 4, the temperature of sapphire substrate 1 was subsequently maintained at 1000 ° C and N.<sub>2</sub>Or H<sub>2</sub>20 liters / minute, NH<sub>3</sub> 10liter / min, TMG 1.53 × 10<sup>-4</sup>Mol / min, DMZ 2 x 10<sup>-7</sup>Mol / min, 10 x 10 silanes<sup>-9</sup>Introduced at mol / min to form a light emitting layer 5 of zinc (Zn) and silicon (Si) -doped GaN with a film thickness of about 0.5 μm.
【0037】
Then keep the temperature at 1000 ° C and N<sub>2</sub>Or H<sub>2</sub>20 liters / minute, NH<sub>3</sub> 10liter / min, TMG 1.12 × 10<sup>-4</sup>Mol / min, TMA 0.47 x 10<sup>-4</sup>Mol / min and CP<sub>2</sub>Mg 2 × 10<sup>-7</sup>Introduced at mol / min for 7 minutes and magnesium (Mg) -doped Al with a film thickness of approximately 0.5 μm.<sub>0.1</sub>Ga<sub>0.9</sub>A p-layer 61 consisting of N was formed. The p layer 61 is still in this state and has a resistivity of 10<sup>8</sup> It is an insulator of Ω cm or more. The concentration of magnesium (Mg) in layer 61 is 1 × 10.<sup>19</sup>/cm<sup>3</sup>Is.
【0038】
Then keep the temperature at 1000 ° C and N<sub>2</sub>Or H<sub>2</sub>20 liters / minute, NH<sub>3</sub> 10liter / min, TMG 1.12 × 10<sup>-4</sup>Mol / min and CP<sub>2</sub>Mg 2 x 10<sup>-4</sup>Introduced at mol / min to form a contact layer 62 made of magnesium (Mg) -doped GaN with a film thickness of about 0.5 μm. Magnesium concentration in contact layer 62 is 1 x 10<sup>20</sup>/cm<sup>3</sup>Is. In this state, the contact layer 62 still has a resistivity of 10.<sup>8</sup> It is an insulator of Ω cm or more.
【0039】
Next, the p layer 61 and the contact layer 62 were uniformly irradiated with electron beams using a reflected electron beam diffractometer. The electron beam irradiation conditions are the same as those in the first embodiment. By irradiation with this electron beam, the p layer 61 and the contact layer 62 have a hole concentration of 2 × 10.<sup>17</sup>/cm<sup>3</sup>, It became a p-conducting semiconductor with a resistivity of 2Ωcm.
【0040】
As described above, a light emitting diode 10 was manufactured by doping the light emitting layer 5 with a zinc (Zn) acceptor and a silicon (Si) donor by a single heterojunction. In the fourth embodiment, the light emitting layer 5 may be made into a p-conducting type by doping the light emitting layer 5 with magnesium (Mg) and irradiating it with an electron beam.
【0041】
Fifth Example Unlike the fourth embodiment, as shown in FIG. 11, the light emitting layer 5 is Al-doped with zinc (Zn) and silicon (Si) at the same time.<sub>x2</sub>Ga<sub>1-x2</sub>N, p layer 61 is magnesium (Mg) doped Al<sub>x1</sub>Ga<sub>1-x1</sub>N, high carrier concentration n<sup>+ </sup>Layer 4 is silicon (Si) doped Al<sub>x3</sub>Ga<sub>1-x3</sub>It is made up of N. And, in the composition ratio x1, x2, x3, the band gap of the light emitting layer 5 has a high carrier concentration n.<sup>+ </sup>It is set so that a double heterojunction or a single heterojunction that is smaller than the band gap of the layer 4 and the p layer 61 is formed. The double heterojunction and the single heterojunction confine the carriers in the light emitting layer 5 and improve the emission brightness. The light emitting layer 5 may be semi-insulating, p-conducting type, or n-conducting type.
【0042】
Sixth Example The light emitting diode of the sixth embodiment is different from the light emitting diode of the fifth embodiment, and as shown in FIG. 12, the light emitting layer 5 is simultaneously doped with zinc (Zn) and silicon (Si).<sub>y</sub>In<sub>1-y</sub>N, p layer 61 is magnesium (Mg) doped Al<sub>x1</sub>Ga<sub>1-x1</sub>N, high carrier concentration n<sup>+ </sup>Layer 4 is silicon (Si) doped Al<sub>x2</sub>Ga<sub>1-x2</sub>It may be formed by N. The composition ratios x1, y, and x2 show that the band gap of the light emitting layer 5 has a high carrier concentration n.<sup>+ </sup>It is set so that a double heterojunction that is smaller than the band gap of layer 4 and p layer 61 is formed. The double heterojunction and the single heterojunction confine the carriers in the light emitting layer 5 and improve the emission brightness. The light emitting layer 5 may be semi-insulating, p-conducting type, or n-conducting type.
【0043】
In FIG. 13, the light emitting diode 10 has a sapphire substrate 1, and a buffer layer 2 of AlN of 500 Å is formed on the sapphire substrate 1. On the buffer layer 2, in order, the film thickness is about 4.0 μm and the electron concentration is 2 × 10.<sup>18</sup>/cm<sup>3</sup>High carrier concentration n consisting of silicon-doped GaN<sup>+ </sup>Layer 4, film thickness about 0.5 μm, zinc and silicon-doped Ga<sub>0.94</sub>In<sub>0.06</sub>Light emitting layer 5 consisting of N, film thickness about 0.5 μm, hole concentration 2 × 10<sup>17</sup>/cm<sup>3</sup>Magnesium-doped Al<sub>0.1</sub>Ga<sub>0.9</sub>P layer 61 consisting of N, film thickness about 0.5 μm, hole concentration 2 × 10<sup>17</sup>/cm<sup>3</sup>A contact layer 62 made of magnesium-doped GaN is formed. Then, the electrode 7 made of nickel connected to the contact layer 62 and the high carrier concentration n<sup>+ </sup>An electrode 8 made of nickel connected to layer 4 is formed. The electrode 7 and the electrode 8 are electrically insulated and separated by a groove 9.
【0044】
Next, a method of manufacturing the light emitting diode 10 having this structure will be described. As in the first embodiment, the buffer layer 2 of AlN is formed. Next, the temperature of the sapphire substrate 1 was maintained at 1150 ° C, the film thickness was about 4.0 μm, and the electron concentration was 2 × 10.<sup>18</sup>/cm<sup>3</sup>High carrier concentration n consisting of silicon-doped GaN<sup>+ </sup>Layer 4 was formed.
【0045】
Hereinafter, examples of composition ratios and crystal growth conditions of the light emitting layer 5, the clad layer, that is, the p layer 61, and the contact layer 62 when the emission peak wavelength is set to 450 nm with zinc (Zn) and silicon (Si) as the emission centers I will write it. The above high carrier concentration n<sup>+ </sup>After forming layer 4, the temperature of sapphire substrate 1 was subsequently maintained at 850 ° C and N.<sub>2</sub>Or H<sub>2</sub>20 liters / minute, NH<sub>3</sub> 10liter / min, TMG 1.53 × 10<sup>-4</sup>Mol / min, TMI 0.02 x 10<sup>-4</sup>Mol / min, DMZ 2 x 10<sup>-7</sup>Mol / min, 10 x 10 silanes<sup>-9</sup>Introduced at mol / min, zinc (Zn) and silicon (Si) -doped Ga with a film thickness of about 0.5 μm<sub>0.94</sub>In<sub>0.06</sub>A light emitting layer 5 of N was formed.
【0046】
Then keep the temperature at 850 ° C and N<sub>2</sub>Or H<sub>2</sub>20 liters / minute, NH<sub>3</sub> 10liter / min, TMG 1.12 × 10<sup>-4</sup>Mol / min, TMA 0.47 x 10<sup>-4</sup>Mol / min and CP<sub>2</sub>Mg 2 × 10<sup>-7</sup>Introduced at mol / min for 7 minutes and magnesium (Mg) -doped Al with a film thickness of approximately 0.5 μm.<sub>0.1</sub>Ga<sub>0.9</sub>A p-layer 61 consisting of N was formed. The p layer 61 is still in this state and has a resistivity of 10<sup>8</sup> It is an insulator of Ω cm or more. The concentration of magnesium (Mg) in layer 61 is 1 × 10.<sup>19</sup>/cm<sup>3</sup>Is.
【0047】
Then keep the temperature at 850 ° C and N<sub>2</sub>Or H<sub>2</sub>20 liters / minute, NH<sub>3</sub> 10liter / min, TMG 1.12 × 10<sup>-4</sup>Mol / min and CP<sub>2</sub>Mg 2 x 10<sup>-4</sup>Introduced at mol / min to form a contact layer 62 made of magnesium (Mg) -doped GaN with a film thickness of about 0.5 μm. Magnesium concentration in contact layer 62 is 1 x 10<sup>20</sup>/cm<sup>3</sup>Is. In this state, the contact layer 62 still has a resistivity of 10.<sup>8</sup> It is an insulator of Ω cm or more.
【0048】
Next, the p layer 61 and the contact layer 62 were uniformly irradiated with electron beams using a reflected electron beam diffractometer. The electron beam irradiation conditions are the same as those in the first embodiment. By irradiation with this electron beam, the p layer 61 and the contact layer 62 have a hole concentration of 2 × 10.<sup>17</sup>/cm<sup>3</sup>, It became a p-conducting semiconductor with a resistivity of 2Ωcm.
【0049】
In the first to sixth embodiments described above, the light emitting layer 5 may be semi-insulating, p-conducting type, or n-conducting type. The concentrations of zinc (Zn) and silicon (Si) mentioned above are 1 × 10, respectively.<sup>17</sup>~1×10<sup>20</sup>It was found that the range of is desirable in terms of improving the emission intensity. More preferably 1 x 10<sup>18</sup>~1 ×10<sup>19</sup>The range of is good. 1 x 10<sup>18</sup>Less is less effective, 1 x 10<sup>19</sup>The more it is, the worse the crystallinity. The concentration of silicon (Si) is preferably 10 times to 1/10, more preferably between 1 and 1/10, or even less than that of zinc (Zn).
【0050】
The light emitting layer 5 is i-type (semi-insulating) if the silicon (Si) concentration is higher than the cadmium (Cd) concentration, and n-conducting if the silicon (Si) concentration is lower than the cadmium (Cd) concentration. Become.
【0051】
Further, in the above embodiment, an example in which cadmium (Cd) was used as the acceptor impurity and silicon (Si) was used as the donor impurity was shown, but the acceptor impurities were beryllium (Be), magnesium (Mg), zinc (Zn), and the like. Cadmium (Cd) and mercury (Hg) may be used. Furthermore, carbon (C), silicon (Si), germanium (Ge), tin (Sn), and lead (Pb) can be used as donor impurities.
【0052】
Furthermore, sulfur (S), selenium (Se), and tellurium (Te) can also be used as donor impurities. For p-type, in addition to electron beam irradiation, thermal annealing, N<sub>2</sub>It can be performed by heat treatment in plasma gas or laser irradiation.
[Simple explanation of drawings]
[Figure 1]
The block diagram which showed the structure of the light emitting diode which concerns on the specific 1st Example of this invention.
[Figure 2]
The cross-sectional view which showed the manufacturing process of the light emitting diode of the same Example.
[Fig. 3]
The cross-sectional view which showed the manufacturing process of the light emitting diode of the same Example.
[Fig. 4]
The cross-sectional view which showed the manufacturing process of the light emitting diode of the same Example.
[Fig. 5]
The cross-sectional view which showed the manufacturing process of the light emitting diode of the same Example.
[Fig. 6]
The cross-sectional view which showed the manufacturing process of the light emitting diode of the same Example.
[Fig. 7]
The cross-sectional view which showed the manufacturing process of the light emitting diode of the same Example.
[Fig. 8]
The block diagram which showed the structure of the light emitting diode which concerns on 2nd Example.
[Fig. 9]
The block diagram which showed the structure of the light emitting diode which concerns on 3rd Example.
[Fig. 10]
The block diagram which showed the structure of the light emitting diode which concerns on 4th Example.
[Fig. 11]
The block diagram which showed the structure of the light emitting diode which concerns on 5th Example.
[Fig. 12]
The block diagram which showed the structure of the light emitting diode which concerns on 6th Example.
[Fig. 13]
The block diagram which showed the structure of the light emitting diode which concerns on 6th Example.
[Explanation of symbols]
10 ... light emitting diode 1 ... Sapphire board 2 ... buffer layer 3 ... High carrier concentration n<sup>+ </sup>layer 4 ... High carrier concentration n<sup>+ </sup>layer 5 ... light emitting layer 6 ... p layer 61 ... p layer 62 ... Cap layer 7,8 ... Electrodes 9 ... groove
Every citation, both waysCites: the store holds 6 of 7
| Document | Relation | Office |
|---|---|---|
| JP5291621A | Cites | Japan |
| JP4242985A | Cites | Japan |
| JP410665A | Cites | Japan |
| JP2264483A | Cites | Japan |
| JP6260680A | Cites | Japan |
| 16871689 | Cites | – |
| 【文献】Jpn.J.Appl.Phys.Part2 Vol.32 No.1A/B(1993)p.L8-L11 | Non-patent | – |
29 members in 4 offices
Priority claims7
| Document | Office | Kind | Date |
|---|---|---|---|
| 676514 | Japan | – | |
| 7651494 | Japan | A | |
| 7651494 | Japan | A | |
| 7436697 | Japan | A | |
| 199476514 | – | – | – |
| JP19940076514 | – | – | – |
| JP19970074366 | – | – | – |
Members29
| Document | Office | Kind | |
|---|---|---|---|
| EP0675552A1 | European Patent Office (EPO) | A1 | |
| JPH07312445A | Japan | A | |
| JPH0846240A | Japan | A | |
| JPH09219538A | Japan | A | |
| EP0911888A2 | European Patent Office (EPO) | A2 | |
| EP0911888A3 | European Patent Office (EPO) | A3 | |
| US6005258A | United States of America | A | |
| JP3016241B2 | Japan | B2 | |
| US6265726B1 | United States of America | B1 | |
| EP0675552B1 | European Patent Office (EPO) | B1 | |
| US2001019849A1 | United States of America | A1 | |
| DE69522026D1 | Germany | D1 | |
| DE69522026T2 | Germany | T2 | |
| JP3307094B2 | Japan | B2 | |
| JP2002289916A | Japan | A | |
| JP3494841B2This record | Japan | B2 | |
| EP0911888B1 | European Patent Office (EPO) | B1 | |
| DE69534387D1 | Germany | D1 | |
| US2005224834A1 | United States of America | A1 | |
| US7001790B2 | United States of America | B2 | |
| US2006118821A1 | United States of America | A1 | |
| DE69534387T2 | Germany | T2 | |
| US7138286B2 | United States of America | B2 | |
| US7332366B2 | United States of America | B2 | |
| US2008173880A1 | United States of America | A1 | |
| US7867800B2 | United States of America | B2 | |
| US2011101412A1 | United States of America | A1 | |
| US2012217510A1 | United States of America | A1 | |
| US2014239313A1 | United States of America | A1 |
5 legal events, as the office reported them to INPADOC
Over the term
Point at a mark for the eventEvents
| Event | Code | |
|---|---|---|
| Cancellation because of no payment of annual feesLAPS | LAPS | |
| Renewal fee payment (event date is renewal date of database)FPAY | FPAY | |
| Renewal fee payment (event date is renewal date of database)FPAY | FPAY | |
| Renewal fee payment (event date is renewal date of database)FPAY | FPAY | |
| Renewal fee payment (event date is renewal date of database)FPAY | FPAY |
Numbers
- Publication
- 3494841
- Publication, DOCDB
- 3494841
- Publication, EPODOC
- JP3494841B
- Application
- 7436697
- Application, DOCDB
- 7436697
- Application, EPODOC
- JP19970074366
Titles2
- Japanese
- 【発明の名称】3族窒化物半導体発光素子
- English
- [Title of Invention] Group 3 Nitride Semiconductor Light Emitting Element
Classification
- IPC, 3
- H01L33 12
- H01L33 32
- H01L33 40