JP2008251641A - Group iii nitride semiconductor element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent Mg in a p-type clad layer from diffusing into an active layer. <P>SOLUTION: The p-type clad layer 15 of a light-emitting diode 1 has a superlattice structure, as shown in Fig.2, in which p-InGaN layers 152 and AlGaN layers 151 are alternately laminated five times on a non-doped AlGaN layer 151a in contact with the active layer. Mg concentrations of the p-InGaN layers 152 are such that Na=Nb<Nc<Nd=Ne where the Mg concentrations of the p-InGaN layers 152a, 152b, 152c, 152d and 152e are respectively Na, Nb, Nc, Nd and Ne and they monotonously increase as coming farther away from the active layer. By thus making the Mg concentrations of the p-InGaN layers 152, the concentration of Mg diffusing into the active layer can be reduced to improve light emission efficiency. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a group III nitride semiconductor device having a p-type semiconductor layer, an active layer, and an n-type semiconductor layer, and in particular, among all the layers stacked on the p-type semiconductor layer side with respect to the active layer. The first p-type semiconductor layer, which is the layer closest to the active layer, has a superlattice structure, and relates to a group III nitride semiconductor device characterized by the p-type impurity concentration of the first p-type semiconductor layer.
In this specification, the concept of “active layer” includes the light receiving layer of the semiconductor light receiving element in addition to the light emitting layer of the semiconductor light emitting element. The semiconductor element of the present invention includes an LED, a semiconductor laser, and a light receiving element.

  Conventionally, in a group III nitride semiconductor light emitting device having a p-type semiconductor layer, an n-type semiconductor layer, and an active layer sandwiched between the p-type semiconductor layer and the n-type semiconductor layer, the p-type semiconductor layer has a superlattice structure. Is known. For example, Patent Document 1 discloses a superlattice structure in which first layers containing Al, such as AlGaN and InGaN, and second layers having a composition different from the first layer are alternately stacked with a thickness of several nm. A p-type semiconductor layer is shown.

In Patent Document 1, in order to solve the problem that the p-type impurity doped in the p-type semiconductor layer diffuses into the active layer and the light emission efficiency decreases, the first of the first layers constituting the superlattice structure is the most. The Al composition ratio of the first layer close to the active layer is made lower than the Al composition ratio of the other first layers, and the p-type impurity doping amount is made smaller than the p-type impurity doping amount of the other first layers. Alternatively, a non-doping method is shown.
JP 2006-108585 A

  However, even if the method of Patent Document 1 is used, the concentration of the p-type impurity diffused from the p-type semiconductor layer to the active layer is high, and defects in the active layer caused by the diffusion of the p-type impurity cause a decrease in luminous efficiency. This will cause output and reliability to deteriorate.

  Accordingly, an object of the present invention is to provide a p-type superlattice structure in which the p-type semiconductor layer closest to the active layer among all the layers stacked on the p-type semiconductor layer side with respect to the active layer, The purpose is to reduce the concentration of p-type impurities in the p-type semiconductor layer having a structure diffusing into the active layer.

  In a Group III nitride semiconductor device having a p-type semiconductor layer, an n-type semiconductor layer, and an active layer between the p-type semiconductor layer and the n-type semiconductor layer, Of all the layers stacked on the semiconductor layer side, the first p-type semiconductor layer, which is the layer closest to the active layer, is a first layer containing Al and a second layer having a different composition from the first layer. Is a superlattice structure in which the first and second layers are doped with p-type impurities and the first p-type semiconductor layer is doped with p-type impurities. In the group III nitride semiconductor device, the p-type impurity concentration increases monotonously as the distance from the active layer increases.

Here, the group III nitride semiconductor is an arbitrary composition ratio represented by the general formula In _x Ga _y Al _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). It is a semiconductor. A semiconductor in which at least a part of Al, Ga, In having the above composition is replaced with B, Tl, or the like, or at least a part of N is replaced with P, As, Sb, Bi, or the like is also a group III nitride semiconductor. Category.

  As the p-type impurity of the group III nitride semiconductor, Mg, Ca and the like can be added, and as the n-type impurity, Si, S, Te, Ge and the like can be added. Two or more elements may be added as these impurities, or both p-type and n-type impurities may be added.

  As described above, the “active layer” includes not only the light emitting layer of the semiconductor light emitting element but also the light receiving layer of the semiconductor light receiving element. Examples of the semiconductor element include an LED, a semiconductor laser, and a light receiving element.

  In the case of a semiconductor laser, the active layer and the first p-type semiconductor layer may be in contact with each other, or a non-doped light guide layer may be provided therebetween. That is, the means of the present invention is effective not only in the active layer but also in the case where the p-type impurity is present in a high concentration in a layer in which light is guided at high density, and the device characteristics deteriorate.

  The p-type impurity may be doped in both the first layer and the second layer, or may be doped only in the first layer or only in the second layer. When both are doped or only the first layer is doped, it is desirable that the first layer closest to the active layer is non-doped.

  When the p-type impurity is doped only in the first layer, the p-type impurity concentration of a certain first layer in the first p-type semiconductor layer is set to the first layer closest to the first layer and on the active layer side. The p-type impurity concentration of the first layer closest to the active layer is set higher than or equal to the p-type impurity concentration of one layer, and higher than the p-type impurity concentration of the first layer closest to the active layer. The p-type impurity concentration in the first layer may be uniform in the film thickness direction, or may increase as the distance from the active layer increases. As a result, the p-type impurity concentration of the first layer doped with the p-type impurity monotonously increases as the distance from the active layer increases. The same applies to the case where only the second layer is doped with p-type impurities.

  When both the first layer and the second layer are doped, the p-type impurity concentration of a certain first layer or second layer in the first p-type semiconductor layer is set to the first layer or the second layer. The p-type impurity concentration of the first layer or the second layer farthest from the active layer is set to be equal to or higher than the p-type impurity concentration of the layer on the active layer side in contact with the first layer or the first layer closest to the active layer. It is higher than the p-type impurity concentration of the two layers. The p-type impurity concentration in the first layer or the second layer may be uniform in the film thickness direction, or may increase as the distance from the active layer increases. As a result, the p-type impurity concentration in the p-type semiconductor layer monotonously increases as the distance from the active layer increases.

  A second invention is a group III nitride semiconductor device according to the first invention, wherein at least one of the first p-type semiconductor layer and the n-type semiconductor layer is in contact with the active layer.

  A third invention is a group III nitride semiconductor device according to the first invention or the second invention, wherein the layer closest to the active layer of the first layer is not doped with a p-type impurity. is there.

  According to a fourth invention, in the first to third inventions, one of the first layer and the second layer is doped with a p-type impurity and the other is not doped with a p-type impurity. This is a group III nitride semiconductor device characterized.

  A fifth invention is a group III nitride semiconductor device according to the first to third inventions, wherein both the first layer and the second layer are doped with a p-type impurity.

According to a sixth invention, in the first to fifth inventions, the first layer is made of Al _x Ga _1-x N (0 <x ≦ 1), and the second layer is In _y Ga _1-y N ( It is a group III nitride semiconductor device characterized by comprising 0 ≦ y ≦ 1).

  A seventh invention is a group III nitride semiconductor device according to the first to sixth inventions, wherein the p-type impurity is Mg.

The eighth invention is the seventh invention, wherein the Mg concentration of the layer farthest from the active layer of the first or second layer doped with Mg is 4 × 10 ^{19 to} 5 × 10 ²⁰ cm ^−3. The group III nitride semiconductor device is characterized in that the Mg concentration in the layer closest to the active layer is lower than 4 × 10 ¹⁹ cm ⁻³ .

Of the first layer or the second layer doped with the p-type impurity, the p-type impurity concentration of the layer farthest from the active layer is preferably in the range of 4 × 10 ^{19 to} 5 × 10 ²⁰ cm ⁻³ . If it is less than 4 × 10 ¹⁹ cm ⁻³ , the hole concentration in the entire first p-type semiconductor layer is low, which is not desirable. If it exceeds 5 × 10 ²⁰ cm ⁻³ , crystal defects due to Mg occur. However, it is not desirable because the hole concentration becomes low. A more desirable range is 4 × 10 ¹⁹ to 2 × 10 ²⁰ cm ⁻³ . Moreover, it is desirable that the p-type impurity concentration of the layer closest to the active layer of the first layer or the second layer doped with the p-type impurity is lower than 4 × 10 ¹⁹ cm ⁻³ . If it exceeds 4 × 10 ¹⁹ cm ⁻³ , the amount of p-type impurities diffusing into the active layer increases, and the light emission efficiency decreases, which is not desirable. More desirable is 3 × 10 ¹⁹ cm ⁻³ or less, and further desirable is non- ^doping .

  According to a ninth aspect of the present invention, there is provided a method for manufacturing a group III nitride semiconductor device having a p-type semiconductor layer, an n-type semiconductor layer, and an active layer between the p-type semiconductor layer and the n-type semiconductor layer. Among all the layers stacked on the p-type semiconductor layer side, the first p-type semiconductor layer, which is the layer closest to the active layer, is different in composition from the first layer containing Al and the first layer. A superlattice structure is formed by alternately laminating the second layer, and at least one of the first layer and the second layer is doped with a p-type impurity, and the p-type impurity of the first p-type semiconductor layer is doped. A method of manufacturing a group III nitride semiconductor device, wherein the first layer and the second layer are formed by monotonically increasing a p-type impurity supply amount of a layer to be doped with increasing distance from an active layer.

  According to a tenth aspect, in the ninth aspect, of the first layer or the second layer to which the p-type impurity is supplied, the p-type impurity supply amount of the layer closest to the active layer is set to the layer farthest from the active layer. This is a method for manufacturing a Group III nitride semiconductor device, characterized in that the supply amount is 0.75 times or less the p-type impurity supply amount.

  In an eleventh aspect based on the tenth aspect, among the first layer or the second layer to which the p-type impurity is supplied, the p-type impurity supply amount of the layer closest to the active layer is set to the layer farthest from the active layer. This is a method for manufacturing a group III nitride semiconductor device, characterized in that the amount of p-type impurity supply is 0.25 times or less.

  According to a twelfth aspect, in the eleventh aspect, the p-type impurity supply amount of a layer closest to the active layer of the first layer or the second layer to which the p-type impurity is supplied is This is a method for manufacturing a group III nitride semiconductor device, characterized in that the amount of p-type impurity supply is 0.1 times or less.

  In the group III nitride semiconductor devices according to the first to eighth inventions, the p-type impurity concentration of the first p-type semiconductor layer is lower as it is closer to the active layer and higher as it is farther from the active layer. Therefore, the diffusion concentration of the p-type impurity from the first p-type semiconductor layer to the active layer can be reduced without reducing the hole concentration in the entire first p-type semiconductor layer. Defects generated in the active layer due to diffusion can be reduced. Therefore, the efficiency of the group III nitride semiconductor device is increased, and the output and reliability are improved.

  According to the Group III nitride semiconductor device manufacturing method of the ninth to twelfth inventions, the p-type impurity concentration of the first p-type semiconductor layer is lower as it is closer to the active layer and higher as it is farther from the active layer. Since it can be formed, a group III nitride semiconductor device with high efficiency and reliability can be manufactured.

  Hereinafter, specific examples of the present invention will be described with reference to the drawings. However, the present invention is not limited to the examples.

FIG. 1 is a diagram illustrating a structure of a light-emitting diode 1 according to the first embodiment. The light emitting diode 1 includes a buffer layer 11, an n-type contact layer 12, an n-type cladding layer 13, an active layer 14, a p-type cladding layer 15, a p-type contact layer 16, and a p ⁺ -type contact layer 17 on a sapphire substrate 10. a structure, which are sequentially stacked, p electrode 18 on the p ⁺ -type contact layer 17 has an n-electrode 19 on the n-type contact layer 12 exposed by etching. The n-type contact layer 12 and the n-type cladding layer 13 correspond to the n-type semiconductor layer of the present invention, and the p-type cladding layer 15, the p-type contact layer 16, and the p ⁺ -type contact layer 17 are the p-type semiconductor of the present invention. The p-type cladding layer 15 corresponds to a first p-type semiconductor layer of the present invention. Hereinafter, the structure will be described in detail.

First, the n-type contact layer 12 and the n-type cladding layer 13 will be described. The n-type contact layer 12 has a structure in which an n ⁺ -GaN layer, a GaN layer, and an n-GaN layer are sequentially stacked on the buffer layer 11. The n-type cladding layer 13 has a superlattice structure in which an InGaN layer and an n-GaN layer are alternately and repeatedly stacked with a thickness of 1 to 6 nm on the n-type contact layer 12. Both the n-type contact layer 12 and the n-type cladding layer 13 are formed by MOCVD using Si as an n-type impurity.

  The active layer 14 has a multiple quantum well structure in which well layers made of InGaN and barrier layers made of GaN are alternately and repeatedly stacked. In addition, a double hetero structure, a single quantum well structure, or the like may be used, but a multiple quantum well structure is preferable in terms of light emission efficiency.

  Next, the structure of the p-type cladding layer 15 will be described. FIG. 2 is an enlarged view showing the structure of the p-type cladding layer. As shown in FIG. 2, the p-type cladding layer 15 includes an undoped AlGaN layer 151 that is not doped with Mg (the first layer of the present invention) and a p-InGaN layer 152 that is doped with Mg (the first layer of the present invention). And a superlattice structure in which two layers are alternately and repeatedly stacked. An AlGaN layer 151a is formed on the active layer 14, and a p-InGaN layer 152 and an AlGaN layer 151 are repeatedly stacked thereon five times. The thicknesses of the AlGaN layer 151 and the p-InGaN layer 152 are 1 to 6 nm. The film thicknesses of the AlGaN layer 151 and the p-InGaN layer 152 are not necessarily the same, and may be different from each other.

FIG. 3 is a view showing the Mg doping amount (supply amount of biscyclopentadienyl magnesium (Cp ₂ Mg), which is a Mg source gas) of each p-InGaN layer 152. The numerical value on the horizontal axis indicates the number of stacked p-InGaN layers 152 counted from the active layer 14 side. The first is the p-InGaN layer 152a (the p-InGaN layer closest to the active layer). 152) second p-InGaN layer 152b, third p-InGaN layer 152c, fourth p-InGaN layer 152d, fifth p-InGaN layer 152e (p-InGaN layer 152 farthest from the active layer) It is. The vertical axis represents the relative Mg doping amount, where the Mg doping amount of the p-InGaN layer 152c is 1. The Mg doping amount of the p-InGaN layer 152a and the p-InGaN layer 152b is 0.4, and the Mg doping amount of the p-InGaN layer 152d and the p-InGaN layer 152e is 1.6. Further, the Mg doping amount in each p-InGaN layer 152 is constant.

By doping Mg as described above, the Mg concentrations Na and Nb of the p-InGaN layers 152a and 152b are 2 × 10 ¹⁹ cm ⁻³ , and the Mg concentration Nc of the p-InGaN layer 152c is 5 × 10 ¹⁹ cm ^−3. The p-InGaN layers 152d and e have Mg concentrations Nd and Ne of 8 × 10 ¹⁹ cm ⁻³ . Na = Nb <Nc <Nd = Ne, and the Mg concentration of the p-InGaN layer 152 monotonously increases as the distance from the active layer 14 increases.

  The Mg concentration distribution of the p-InGaN layer 152 is not limited to the above example, and may be anything as long as the Mg concentration of the p-InGaN layer 152 monotonously increases as the distance from the active layer 14 increases. For example, the Mg concentrations of the p-InGaN layers 152a to 152e may be all different values such as Na <Nb <Nc <Nd <Ne, or Na <Nb = Nc <Nd <Ne, Na <Nb = Nc < There may be layers with the same Mg concentration, such as Nd = Ne, Na <Nb = Nc = Nd <Ne, Na <Nb <Nc = Nd = Ne.

  The Mg doping amount in each p-InGaN layer 152 is constant, but the Mg doping amount in the p-InGaN layer 152 may be increased as the distance from the active layer 14 increases.

The Mg concentration of the p-InGaN layer 152a closest to the active layer 14 is desirably lower than 4 × 10 ¹⁹ cm ⁻³ . This is because when the concentration is 4 × 10 ¹⁹ cm ⁻³ or more, the concentration of Mg diffusing from the p-InGaN layer 152a to the active layer 14 increases and the light emission efficiency decreases. The Mg concentration of the p-InGaN layer 152e farthest from the active layer 14 is preferably in the range of 4 × 10 ^{19 to} 5 × 10 ²⁰ cm ⁻³ . If it is less than 4 × 10 ¹⁹ cm ⁻³ , the hole concentration in the entire p-type cladding layer 15 is low, which is not desirable. If it exceeds 5 × 10 ²⁰ cm ⁻³ , crystal defects due to Mg are generated and positive. This is not desirable because the pore concentration is low.

  Further, in Example 1, the number of repetitions of the p-InGaN layer 152 and the AlGaN layer 151 is five, but is not limited to five and may be in the range of 4 to 8 times.

A p-type contact layer 16 made of p-GaN and a p ⁺ -type contact layer 17 made of p ⁺ -GaN are formed on the p-type cladding layer 15. A p-electrode 18 is deposited on the p ⁺ -type contact layer 17 by vapor deposition. Is formed. The n electrode 19 is formed by vapor deposition on the surface of the n-type contact layer 11 exposed by etching.

  The light emitting diode 1 having the above configuration has a structure in which the Mg concentration of the p-InGaN layer 152 in the p-type cladding layer 15 increases as the distance from the active layer 14 increases, in other words, the Mg concentration decreases as the distance from the active layer 14 increases. Structure. Therefore, Mg can be prevented from diffusing from the p-type cladding layer 15 to the active layer 14, and defects generated in the active layer 14 due to the diffusion of Mg can be reduced. As a result, the light emission efficiency of the light emitting diode 1 is improved as compared with the conventional light emitting diode, and the light output and reliability are improved.

FIG. 4 is a diagram comparing the light output of the light emitting diode 1 of Example 1 and the light output of the light emitting diode of the comparative example. Here, the light-emitting diode of the comparative example has the same structure as the light-emitting diode 1 of Example 1 except for the Mg concentration of the p-InGaN layer in the p-type cladding layer. As shown in FIG. 3, the Mg doping amount of each p-InGaN layer is equal to the Mg doping amount of the p-InGaN layer 152c of Example 1 as shown in FIG. The Mg doping amount of the entire p-type cladding layer of the comparative example is the same as the Mg doping amount of the entire p-type cladding layer 15 of Example 1. Therefore, the Mg concentration of the p-InGaN layer in the p-type cladding layer of the comparative example is all 4 × 10 ¹⁹ cm ⁻³ . As shown in FIG. 4, it can be seen that the light output of the light emitting diode 1 of Example 1 is about 10% higher than that of the light emitting diode of the comparative example.

  In Example 1, Mg is doped only in the InGaN layer out of the AlGaN layer and the InGaN layer constituting the p-type cladding layer, but conversely, Mg may be doped only in the AlGaN layer other than the AlGaN layer 151a. . Similar to the light-emitting diode 1 of Example 1, the concentration at which Mg diffuses into the active layer can be reduced, and the luminous efficiency can be improved.

  FIG. 5 is a diagram illustrating the structure of the p-type cladding layer 25 of the light-emitting diode 2 according to the second embodiment. The structure of the light emitting diode 2 other than the structure of the p-type cladding layer 25 is the same as that of the light emitting diode 1. As shown in FIG. 5, the p-type cladding layer 25 is formed by alternately repeating the p-InGaN layer 252 and the p-AlGaN layer 251 on the Mg-doped AlGaN layer 253 in contact with the active layer 14. It has a superlattice structure.

  The p-InGaN layer 252 and the p-AlGaN layer 251 are doped with Mg so that the Mg concentration increases monotonously as the distance from the active layer increases. Therefore, the Mg concentration in the p-type cladding layer 25 excluding the AlGaN layer 253 monotonously increases as the distance from the active layer increases. As long as the p-InGaN layer 252 and the p-AlGaN layer 251 in contact with the p-InGaN layer 252 are configured so as to increase monotonously in this way, the Mg concentration may be equal.

  The Mg doping amount in each p-AlGaN layer 251 and each p-InGaN layer 152 may be constant, or the Mg doping amount may increase as the distance from the active layer 14 increases.

Of the p-InGaN layer 252 and the p-AlGaN layer 251 doped with Mg, the Mg concentration of the p-InGaN layer 252a closest to the active layer is preferably lower than 4 × 10 ¹⁹ cm ⁻³ . Of the p-InGaN layer 252 and the p-AlGaN layer 251 doped with Mg, the Mg concentration of the p-AlGaN layer 251a farthest from the active layer is in the range of 4 × 10 ^{19 to} 5 × 10 ²⁰ cm ⁻³ . It is desirable that The desirable reason is the same as described in the first embodiment.

  The light-emitting diode 2 having the above configuration can suppress the diffusion of Mg in the p-type cladding layer 25 into the active layer 14 in the same manner as the light-emitting diode 1 of the first embodiment. Will improve.

  In Examples 1 and 2, the p-type cladding layer has a superlattice structure in which AlGaN layers and InGaN layers are alternately and repeatedly stacked. However, the present invention is limited to a superlattice structure including an AlGaN layer and an InGaN layer. Instead, any superlattice structure in which a group III nitride semiconductor layer containing Al and a group III nitride semiconductor layer having a different composition are alternately stacked may be used. For example, a superlattice structure of an AlGaN layer and a GaN layer or a superlattice structure of an AlGaInN layer and an InGaN layer may be used.

  Although both the first and second embodiments are light emitting diodes, the present invention is not limited to light emitting diodes but can be applied to semiconductor lasers and light receiving elements.

  In the case of the light emitting diode as in Examples 1 and 2, it is desirable that the layer containing Al in the p-type cladding layer is in contact with the active layer.

  In the case of a semiconductor laser, the p-type cladding layer and the active layer may be in contact with each other, or a non-doped light guide layer may be provided between the p-type cladding layer and the active layer.

  According to the present invention, a light-emitting element with high emission efficiency and high reliability can be realized.

1 is a diagram illustrating a structure of a light-emitting diode 1 of Example 1. FIG. FIG. 3 is a diagram showing a structure of a p-type cladding layer 15 of the light-emitting diode 1 of Example 1. The figure which shows the Mg doping amount of each p-InGaN layer 152. FIG. The figure which compared the light output of the light emitting diode 1 of Example 1, and the light emitting diode of a comparative example. FIG. 6 is a diagram showing a structure of a p-type cladding layer 25 of the light-emitting diode 2 of Example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2: Light emitting diode 10: Sapphire substrate 12: N-type contact layer 13: N-type cladding layer 14: Active layer 15, 25: P-type cladding layer 16: P-type contact layer 17: P ⁺ type contact layer 151,253 : AlGaN layer 152, 252: p-InGaN layer 251: p-AlGaN layer

Claims (12)

In a group III nitride semiconductor device having a p-type semiconductor layer, an n-type semiconductor layer, and an active layer between the p-type semiconductor layer and the n-type semiconductor layer,
Of all the layers stacked on the p-type semiconductor layer side with respect to the active layer, the first p-type semiconductor layer that is the layer closest to the active layer includes a first layer containing Al, The first layer is a superlattice structure in which second layers having different compositions are laminated alternately,
At least one of the first layer and the second layer is doped with a p-type impurity,
The group III nitride semiconductor device, wherein the p-type impurity concentration of the layer doped with the p-type impurity of the first p-type semiconductor layer monotonously increases as the distance from the active layer increases.   2. The group III nitride semiconductor device according to claim 1, wherein at least one of the first p-type semiconductor layer and the n-type semiconductor layer is in contact with the active layer.   3. The group III nitride semiconductor device according to claim 1, wherein a layer closest to the active layer among the first layers is not doped with a p-type impurity. 4.   4. The method according to claim 1, wherein one of the first layer and the second layer is doped with p-type impurities, and the other is not doped with p-type impurities. A group III nitride semiconductor device as described in 1.   4. The group III nitride semiconductor device according to claim 1, wherein both the first layer and the second layer are doped with a p-type impurity. 5. The first layer is made of Al _x Ga _1-x N (0 <x ≦ 1), and the second layer is made of In _y Ga _1-y N (0 ≦ y ≦ 1). The group III nitride semiconductor device according to any one of claims 1 to 5.   The group III nitride semiconductor device according to any one of claims 1 to 6, wherein the p-type impurity is Mg. Of the first layer or the second layer doped with Mg, the Mg concentration of the layer farthest from the active layer is 4 × 10 ^{19 to} 5 × 10 ²⁰ cm ⁻³ , and is the layer closest to the active layer. The group III nitride semiconductor device according to claim 7, wherein the Mg concentration is lower than 4 × 10 ¹⁹ cm ⁻³ . In the method of manufacturing a group III nitride semiconductor device having a p-type semiconductor layer, an n-type semiconductor layer, and an active layer between the p-type semiconductor layer and the n-type semiconductor layer,
Of all the layers stacked on the p-type semiconductor layer side with respect to the active layer, the first p-type semiconductor layer which is the layer closest to the active layer includes a first layer containing Al, A superlattice structure is formed by alternately stacking second layers having different compositions from the first layer,
At least one of the first layer and the second layer is doped with a p-type impurity,
The p-type impurity supply amount of the layer doped with p-type impurities of the first p-type semiconductor layer is monotonously increased as the distance from the active layer is increased to form the first layer and the second layer. A method for producing a group III nitride semiconductor device.   Of the first layer or the second layer to which the p-type impurity is supplied, the p-type impurity supply amount of the layer closest to the active layer is set to 0. 0 of the p-type impurity supply amount of the layer farthest from the active layer. 10. The method for producing a group III nitride semiconductor device according to claim 9, wherein the number is 75 times or less.   Of the first layer or the second layer to which the p-type impurity is supplied, the p-type impurity supply amount of the layer closest to the active layer is set to 0. 0 of the p-type impurity supply amount of the layer farthest from the active layer. The method for producing a group III nitride semiconductor device according to claim 10, wherein the number is 25 times or less.   Of the first layer or the second layer to which the p-type impurity is supplied, the p-type impurity supply amount of the layer closest to the active layer is set to 0. 0 of the p-type impurity supply amount of the layer farthest from the active layer. The method for producing a group III nitride semiconductor device according to claim 11, wherein the production amount is 1 times or less.

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