KR100604423B1 - Nitride semiconductor device - Google Patents

Abstract

The present invention relates to a nitride semiconductor device, comprising: a substrate, an n-type cladding layer formed on the substrate, an active layer formed on a portion of the n-type cladding layer, and a first p formed on the active layer A p-type superlattice layer and a p-type superlattice layer having a multi-layer structure by sequentially stacking nitride semiconductor layers having different energy bands on the first p-type cladding layer, and formed on the p-type superlattice layer A nitride comprising a second p-type cladding layer, a p-type electrode formed on the second p-type cladding layer, and an n-type electrode formed on an n-type cladding layer in which the active layer is not formed. It relates to a semiconductor device.

Nitride, Superlattice layer, Energy bandgap, Short wavelength, Electrostatic discharge (ESD), Operating voltage

Description

Nitride Semiconductor Devices {NITRIDE SEMICONDUCTOR DEVICE}

1 is a cross-sectional view showing the structure of a nitride semiconductor device (LED) according to the prior art.

2 is a cross-sectional view illustrating a structure of a nitride semiconductor device (LED) according to a first embodiment of the present invention.

3 is a partial sectional view showing a p-type superlattice layer according to a first modification of the first embodiment;

4 is a graph schematically showing an example of an energy band gap profile of the p-type superlattice layer of FIG. 3.

Fig. 5 is a partial sectional view showing a p-type superlattice layer according to a second modification of the first embodiment.

FIG. 6 is a graph schematically showing an example of an energy band gap profile of the p-type superlattice layer of FIG. 5. FIG.

7 is a partial cross-sectional view showing a p-type superlattice layer according to a third modification of the first embodiment

FIG. 8 is a graph schematically showing an example of an energy band gap profile of the p-type superlattice layer of FIG. 7.

9 is a partial cross-sectional view showing a p-type superlattice layer according to a fourth modification of the first embodiment

FIG. 10 is a graph schematically showing an example of an energy band gap profile of the p-type superlattice layer of FIG. 9. FIG.

11 is a cross-sectional view illustrating a structure of a nitride semiconductor device (LED) according to a second embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100 substrate 110 buffer layer

120: n-type cladding layer 130: active layer

140a: first p-type cladding layer 140b: second p-type cladding layer

150: transparent conductor layer 160: p-type electrode

170: n-type electrode 200: p-type superlattice layer

210: stress buffer layer 300: n-type superlattice layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device such as a light emitting diode (LED), a laser diode (LD), a light emitting device such as a solar cell, an optical sensor, or a nitride semiconductor device used for electronic devices such as transistors and power devices.

Recently, III-V nitride semiconductors such as GaN have been spotlighted as core materials of light emitting devices such as light emitting diodes (LEDs) or laser diodes (LDs) due to their excellent physical and chemical properties. LEDs or LDs using III-V nitride semiconductor materials are widely used in light emitting devices for obtaining light in the blue or green wavelength band, and these light emitting devices are applied to light sources of various products such as electronic displays and lighting devices. The III-V nitride semiconductor is generally made of a GaN-based material having a composition formula of In _X Al _Y Ga _{1 -X- Y} N (0≤X, 0≤Y, X + Y≤1).

Next, a conventional nitride semiconductor device (LED) using a III-V nitride semiconductor as described above will be described in detail with reference to FIG. 1.

1 is a cross-sectional view schematically showing a structure of a nitride semiconductor device (LED) according to the prior art.

As shown in FIG. 1, an LED device using a nitride semiconductor according to the related art includes a buffer layer 110 made of GaN, an n-type cladding layer 120, and a single quantum well on a sapphire substrate 100 that is a light transmissive substrate. An active layer 130 and a p-type cladding layer 140 of a multi-quantum well (MQW) structure containing InGaN or InGaN having an (SQW) structure are sequentially stacked.

In addition, since some regions of the p-type cladding layer 140 and the active layer 130 are removed by some mesa etching process, some top surfaces of the n-type cladding layer 120 are exposed. In addition, an n-type electrode 170 is formed on the exposed n-type cladding layer 120, and on the p-type cladding layer 160, the transparent conductor layer 150 and the p-type electrode 160 made of ITO or the like. It is formed in this stacked structure.

As described above, the nitride semiconductor device (LED) may adopt a double heterostructure having an active layer 130 having a single quantum well structure or a multi quantum well structure having a well layer made of InGaN.

In particular, in the nitride semiconductor device (LED), the multi-quantum well structure has a large number of mini bands, has high efficiency, and can emit light even at a small current, so that the light emission output is higher than that of the single quantum well structure. Improvement is expected. This discloses an active layer having a multi-quantum well structure consisting of a barrier layer of undoped GaN and a well layer of undoped InGaN in order to improve luminous efficiency and luminous intensity in Japanese Patent Laid-Open No. 10-135514. In addition, a nitride semiconductor device including a cladding layer having a band gap larger than that of the barrier layer of the active layer is disclosed.

However, when the active layer has a multi-quantum well structure, high luminous efficiency and luminous intensity can be obtained. However, there is a limit in luminous efficiency and luminous intensity, that is, light output, for using a nitride semiconductor element as a light source for illumination or an outdoor display. have. In addition, when the active layer has a multi-quantum well structure, the thickness of the entire active layer is higher than that of the single quantum well structure, so that the series resistance in the longitudinal direction is high, and in particular, in the case of LED elements, the operating voltage (V _f ). There is a problem of getting higher.

However, as described above, when the operating voltage of the LED device is increased, since the blue-shift of the center wavelength of the LED device is shortened due to the concentration of the current density, there is a problem that the luminous efficiency is reduced.

In addition, since the light emitting device using the nitride semiconductor is generally poor in resistance to electrostatic discharge (ESD), it is necessary to improve the electrostatic discharge characteristics. In particular, the nitride semiconductor LED device or LD device has a problem that can be damaged by the static electricity easily generated in people or things in the process of handling or using the same.

Accordingly, in order to suppress damage of the nitride semiconductor device due to ESD, various studies have recently been conducted. For example, US Pat. No. 6,593,597 discloses a technique for protecting an LED device from ESD by integrating the LED device and the Schottky diode on the same substrate and connecting the LED device and the Schottky diode in parallel. In addition, in order to improve ESD resistance, a method of connecting an LED device in parallel with a Zener diode has been proposed.

However, these methods have the problem of purchasing and assembling a separate zener diode or forming a Schottky junction, thereby increasing the overall manufacturing cost of the device.

The present invention is to solve the above problems, an object of the present invention is to lower the operating voltage (V _f ), improve the current diffusion effect to minimize the blue-shift phenomenon of the LED device, and to improve luminous efficiency An object of the present invention is to provide a nitride semiconductor element that can be increased.

In addition, an object of the present invention is to provide a nitride semiconductor device that can implement a high ESD resistance without having to provide a separate device for improving the ESD resistance.

In order to achieve the above object, the present invention provides a substrate, an n-type cladding layer formed on the substrate, an active layer formed on a portion of the n-type cladding layer, and a first formed on the active layer. a p-type cladding layer and a p-type superlattice layer having a multi-layer structure by sequentially stacking nitride semiconductor layers having different energy bands on the first p-type cladding layer, and on the p-type superlattice layer And a second p-type cladding layer formed, a p-type electrode formed on the second p-type cladding layer, and an n-type electrode formed on an n-type cladding layer on which the active layer is not formed. Provided is a nitride semiconductor device.

Further, in the nitride semiconductor element of the present invention, the nitride semiconductor layer constituting the p-type superlattice layer is In _X Al _Y Ga _{1 -X- Y} N (0≤X, 0≤Y, X + Y≤1 ) Composition, it is preferable to have a different energy band by varying the composition ratio of Al and In.

Further, in the nitride semiconductor device of the present invention, the p-type superlattice layer, the first nitride semiconductor layer higher than the energy band of the p-type cladding layer and the second nitride lower than the energy band of the p-type cladding layer The semiconductor layers are alternately stacked one or more times, or the p-type superlattice layer is higher than the energy band of the first nitride semiconductor layer and the p-type cladding layer, which is lower than the energy band of the p-type cladding layer. It is preferable that the second nitride semiconductor layers are formed by alternately stacking one or more times.

Further, in the nitride semiconductor device of the present invention, at least one nitride semiconductor layer in which an energy band is sequentially increased in either direction between the first nitride semiconductor layer and the second nitride semiconductor layer constituting the p-type superlattice layer. It is preferable to include.

Further, in the nitride semiconductor device of the present invention, it is preferable that all or part of the nitride semiconductor layer constituting the p-type superlattice layer is selectively doped with p-type impurities, and the doping concentration of the p-type impurity is The nitride semiconductor layer constituting the p-type superlattice layer may be formed differently or constantly.

In addition, in the nitride semiconductor device of the present invention, the first p-type cladding layer preferably includes a separate UDMHy source injected during growth, and thus, it is possible to omit the heat treatment process for p-type activation. This can simplify the overall manufacturing process of the device.

Further, in the nitride semiconductor device of the present invention, it is preferable to further include a transparent conductor layer formed between the second p-type cladding layer and the p-type electrode. The transparent conductor layer may further increase the current diffusion effect by increasing the injection area of the current injected through the p-type electrode.

In addition, in the nitride semiconductor device of the present invention, it is preferable that the n-type cladding layer and the n-type superlattice layer of a multilayer structure in which a nitride semiconductor layer having a different energy band between the active layer is sequentially laminated. .

Further, in the nitride semiconductor device of the present invention, the n-type superlattice layer, the first nitride semiconductor layer higher than the energy band of the n-type cladding layer and the second nitride lower than the energy band of the n-type cladding layer The semiconductor layers are alternately stacked one or more times, or the n-type superlattice layer is higher than the energy band of the first nitride semiconductor layer and the n-type cladding layer, which is lower than the energy band of the n-type cladding layer. It is preferable that the second nitride semiconductor layers are formed by alternately stacking one or more times.

Further, in the nitride semiconductor device of the present invention, at least one nitride semiconductor layer in which an energy band sequentially increases in either direction between the first nitride semiconductor layer and the second nitride semiconductor layer constituting the n-type superlattice layer. It is preferable to include.

In the nitride semiconductor device of the present invention, it is preferable that all or part of the nitride semiconductor layer of the n-type superlattice layer is doped with n-type impurities, and the doping concentration of the n-type impurities is n. The nitride semiconductor layer constituting the type superlattice layer may be formed differently or constantly.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like reference numerals designate like parts throughout the specification.

A nitride semiconductor device according to an embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[ Example  One]

First, the nitride semiconductor device according to the first embodiment of the present invention will be described in detail with reference to FIG. 2.

2 is a plan view showing the structure of the nitride semiconductor device according to the first embodiment of the present invention.

As shown in FIG. 2, a light transmissive substrate 100, a buffer layer 110, an n-type cladding layer 120, an active layer 130, and a first p-type cladding layer 140a are formed on the substrate 100. ), a p-type super lattice 200, and a second p-type cladding layer 140b are sequentially stacked.

The substrate 100 is a substrate suitable for growing a nitride semiconductor single crystal, and may be a heterogeneous substrate such as a sapphire substrate and a silicon carbonate (SiC) substrate or a homogeneous substrate such as a nitride substrate.

The buffer layer 110 is a layer for improving lattice matching with the sapphire substrate 110 before the n-type cladding layer 120 is grown, and is generally formed of AlN / GaN.

The n-type cladding layer 120, the first and second p-type cladding layers 140a and 140b, and the active layer 130 have an In _X Al _Y Ga _{1-X- Y} N composition formula (where 0 ≦ _X , 0 ≤ Y, X + Y ≤ 1). More specifically, the n-type cladding layer 120 may be formed of a GaN layer or a GaN / AlGaN layer doped with n-type conductive impurities, for example, Si, Ge, Sn, etc. Is used, and preferably Si is mainly used. In addition, the first and second p-type cladding layers 140a and 140b may be formed of a GaN layer or a GaN / AlGaN layer doped with a p-type conductive impurity, for example, Mg , Zn, Be and the like are used, and preferably Mg is mainly used. In addition, the first p-type cladding layer 140a may further grow by additionally adding a separate UDMHy source, thereby simplifying the overall manufacturing process of the device by omitting a heat treatment process for p-type activation. The active layer 130 may be formed of an InGaN / GaN layer having a multi-quantum well structure.

In particular, in the present invention, a p-type superlattice having a multilayer structure in which nitride semiconductor layers having different energy bands are sequentially stacked on an interface between the p-type cladding layer 140a and the second p-type cladding layer 140b. Layer 200 is formed. This increases the cladding effect and the current diffusion effect of the first and second p-type cladding layers 140a and 140b, minimizes the blue-shift phenomenon, and reduces the resistance of the electrostatic discharge (ESD) characteristics. It is to strengthen.

In the nitride semiconductor device according to the present invention, the first and second p-type cladding layers 140a and 140b, the p-type superlattice layer 200, and the active layer 130 are etched to form the n-type cladding layer 120. A plurality of mesas formed by exposing a portion of the upper surface of the c), an n-type electrode 170 formed on the exposed n-type cladding layer 120 on the plurality of mesas, and the second p-type clad to spread current. The transparent conductor layer 150 formed on the layer 140b and the p-type electrode 160 serving as the reflective metal and the bonding metal on the transparent conductor layer 150 are included.

In the light emitting structure of the present invention, the transparent conductor layer 150 is a layer for improving the current diffusion effect by increasing the current injection area, ITO (Indium Tin Oxide), TO (Tin Oxide), IZO (Indium Zinc) Oxide), ITZO (Indium Tin Zinc Oxide) and TCO (Transparent Conductive Oxide) is preferably made of any one film selected from the group consisting of.

Next, a specific type of the p-type superlattice layer 200 having a multilayer structure in which nitride semiconductor layers having different energy bands are sequentially stacked will be described with reference to FIGS. 3 to 10.

Variant  One

The p-type superlattice layer of the nitride semiconductor element according to the first modification of the present embodiment will be described in detail with reference to FIGS. 3 and 4.

3 is a partial cross-sectional view illustrating a p-type superlattice layer according to a first modification of the present embodiment, and FIG. 4 is a graph schematically showing an example of an energy bandgap profile of the p-type superlattice layer of FIG. 3.

Referring to FIG. 3, nitride semiconductor layers having different energy bands, for example, first and second p-type cladding, are provided at an interface between the first p-type cladding layer 140a and the second p-type cladding layer 140b. Based on the energy bands of the layers 140a and 140b, the first nitride semiconductor layer 200a having a higher energy band and the second nitride semiconductor layer 200b having a lower energy band are alternately stacked a plurality of times. The p-type superlattice layer 200 is formed. In this case, the first and the second nitride semiconductor layer (200a, 200b) is a semiconductor material having an In _X Al _Y Ga _{1-X- Y} N composition formula (where 0≤X, 0≤Y, X + Y≤1) It consists of and has different energy bands through different composition ratios of In and Al. In the present embodiment, GaN is used as the p-type cladding layer 120, AlGaN is used as the first nitride semiconductor layer 200a, and InGaN is used as the second nitride semiconductor layer 200b. In addition, it is preferable that all or part of the nitride semiconductor layer constituting the p-type superlattice layer 200 is doped with p-type impurities. In this case, the doping concentration of the p-type impurity may be differently or uniformly formed for each position of the nitride semiconductor layer constituting the p-type superlattice layer 200 according to process conditions and process characteristics.

Accordingly, the p-type superlattice layer 200 according to the present embodiment has different energy bands of the first nitride semiconductor layer 200a and the second nitride semiconductor layer 200b, that is, as shown in FIG. 5. The discontinuity of the energy band in which the energy band changes rapidly at the interface between the first nitride semiconductor layer 200a and the second nitride semiconductor layer 200b forms a two-dimensional electron gas layer (not shown) at the interface.

Accordingly, when voltage is applied, a tunneling phenomenon occurs through the two-dimensional electron gas layer through the n ⁺ -p ⁺ junction, thereby improving the cladding effect of the first and second p-type cladding layers 140a and 140b, and providing high carriers. The mobility can be secured to improve the current spreading effect. As such, when the current diffusion effect in the p-type superlattice layer 200 is improved, the operating voltage V _f is lowered and the blue-shift phenomenon is minimized due to the increase in the emission area, thereby improving the luminous efficiency. Since it is improved, it is possible to implement a nitride semiconductor device to secure the light output. In particular, the blue-shift phenomenon decreases as the In flow rate of the nitride semiconductor layer having a low energy band gap is increased due to the high composition of In in the nitride semiconductor layer forming the p-type superlattice layer. do.

In addition, since the p-type superlattice layer 200 is interposed between the first and second p-type cladding layers 140a and 140b to have a relatively high dielectric constant, the p-type superlattice layer 200 serves as a kind of capacitor. You can play a role. Accordingly, the p-type superlattice layer 200 can protect the nitride semiconductor device from sudden surge voltage or electrostatic phenomenon, thereby improving the ESD resistance of the device.

Variant  2

5 and 6, a second modification of the present embodiment will be described. However, the description of the same parts as the first modification of the configuration of the second modification is omitted, and only the configuration that is different from the second modification will be described in detail.

5 is a partial cross-sectional view illustrating a p-type superlattice layer according to a second modified example of the present embodiment, and FIG. 6 is a graph schematically showing an example of an energy bandgap profile of the p-type superlattice layer of FIG. 5.

5 and 6, the p-type superlattice layer 200 according to the second modification is the same as most of the configuration of the p-type superlattice layer 200 according to the first modification, The first nitride semiconductor layer formed on the first p-type cladding layer 140a is not the first nitride semiconductor layer 200a having an energy band higher than that of the first p-type cladding layer 140a. It differs from the first modification only in that it is the second nitride semiconductor 200b having an energy band lower than that of the p-type cladding layer 140a.

That is, the first modification is the p-type superlattice layer, which is higher than the energy bands of the first and second p-type cladding layers and the energy bands of the first and second p-type cladding layers. The lower second nitride semiconductor layer is formed by alternately stacking one or more times alternately, and the second modification is the p-type superlattice layer than the energy bands of the first and second p-type cladding layers. The lower first nitride semiconductor layer and the second nitride semiconductor layer higher than the energy bands of the first and second p-type cladding layers are alternately formed one or more times and repeatedly formed.

Therefore, this second modification can obtain the same effects and effects as in the first modification.

Variant  3

Hereinafter, a third modification of the present embodiment will be described with reference to FIGS. 7 and 8. However, the description of the same parts as the first modification of the configuration of the third modification is omitted, and only the configuration that is different from the third modification will be described in detail.

7 is a partial cross-sectional view illustrating a p-type superlattice layer according to a third modified example of the present embodiment, and FIG. 8 is a graph schematically showing an example of an energy bandgap profile of the p-type superlattice layer of FIG. 7.

As shown in FIG. 7 and FIG. 8, the p-type superlattice layer 200 according to the third modified example has the same configuration as that of the p-type superlattice layer 200 according to the first modified example. Further comprising a stress buffer layer 210, which is one or more layers of the nitride semiconductor layer in which the energy band sequentially increases in either direction between the first nitride semiconductor layer 200a and the second nitride semiconductor layer 200b. It differs from the 1st modification only in the point. In this case, the stress buffer layer 210 is made of a semiconductor material having an In _X Al _Y Ga _{1 -X- Y} N composition formula (where 0≤X, 0≤Y, X + Y≤1), and In and Al The ratio of the energy band gap between the first nitride semiconductor layer 200a and the second nitride semiconductor layer 200b is controlled through different composition ratios.

Therefore, the third modification can obtain the same functions and effects as those in the first modification, and the stress buffer layer 210 formed between the first nitride semiconductor layer 200a and the second nitride semiconductor layer 200b can be obtained. By buffering a rapidly changing energy bandgap at the interface between the first nitride semiconductor layer 200a and the second nitride semiconductor layer 200b, the device can be more stably maintained.

On the other hand, although not shown, such a stress buffer layer 210 can be applied to the p-type superlattice layer described in the second modification of the present invention.

Variant  4

Hereinafter, a fourth modification of the present embodiment will be described with reference to FIGS. 9 and 10. However, the description of the same parts as the third modification of the configuration of the fourth modification will be omitted, and only the configuration different from the third modification will be described in detail.

9 is a partial cross-sectional view illustrating a p-type superlattice layer according to a fourth modified example of the present embodiment, and FIG. 10 is a graph schematically showing an example of an energy bandgap profile of the p-type superlattice layer of FIG. 9.

9 and 10, the p-type superlattice layer 200 according to the fourth modified example has the same structure as that of the p-type superlattice layer according to the third modified example, except that the fourth type is the same. In the modification, the three-layer structure in which the first nitride semiconductor layer 200a, the second nitride semiconductor layer 200b, and the first nitride semiconductor layer 200a are sequentially stacked is repeatedly stacked a plurality of times in one cycle. One layer in which an energy band sequentially increases in either direction between the first nitride semiconductor layer 200a and the second nitride semiconductor layer 200b and between the second nitride semiconductor layer 200b and the first nitride semiconductor layer 200b. It differs from the third modification only in that it further includes a stress buffer layer 210 which is a nitride semiconductor layer.

Therefore, the fourth modification has an advantage that the same operation and effect as in the third modification can be obtained.

[ Example  2]

Next, the nitride semiconductor device according to the second embodiment of the present invention will be described with reference to FIG. 11. However, the description of the same parts as those of the first embodiment of the configuration of the second embodiment will be omitted, and only the configuration that is different from the second embodiment will be described in detail.

11 is a cross-sectional view illustrating a structure of a nitride semiconductor device (LED) according to a second embodiment of the present invention.

As shown in FIG. 11, the nitride semiconductor device according to the second embodiment has the same structure as that of the nitride semiconductor device according to the first embodiment, except that the n-type cladding layer 120 and the active layer 130 are provided. The first embodiment differs only in that an n-type superlattice layer 300 having a multilayer structure in which nitride semiconductor layers having different energy bands are sequentially stacked is formed at an interface between them.

That is, the first embodiment illustrates that a p-type superlattice layer is formed between the first and second p-type cladding layers, and the second embodiment is provided between the first and second p-type cladding layers. It further illustrates that the p-type superlattice layer formed and the n-type superlattice layer formed between the n-type cladding layer and the active layer are further included.

On the other hand, the n-type superlattice layer may have the same modifications as the above-described modifications of the p-type superlattice layer, thereby, can obtain the same action and effect as the modifications of the p-type superlattice layer have.

That is, this second embodiment can not only achieve the same effects and effects as in the first embodiment, but also cladding the n-type cladding layer through the n-type superlattice layer located between the n-type cladding layer and the active layer. The cladding effect and the current diffusion effect can also be improved.

Although the preferred embodiments of the present invention have been described in detail above, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

As described above, the present invention includes a superlattice layer having a multilayer structure formed by sequentially stacking nitride semiconductor layers having different energy bands between the p-type cladding layers, thereby providing a cladding effect of the p-type cladding layer and Current diffusion effect can be improved.

As described above, the present invention implements a nitride semiconductor device capable of obtaining high light output by lowering the operating voltage V _f and minimizing the blue-shift due to the improvement of the current diffusion effect.

In addition, the present invention provides a superlattice layer having a multi-layered structure formed by sequentially stacking nitride semiconductor layers having different energy bands between an n-type cladding layer and an active layer, thereby providing a cladding effect and a current The diffusion effect can be improved.

In addition, in the present invention, since a structure in which nitride semiconductor layers having different energy bands of the superlattice layer are sequentially stacked serves as a kind of capacitor, ESD resistance is not required to include a separate device for improving ESD resistance. The nitride semiconductor device having high reliability can be realized by improving the efficiency.

Claims (16)

Board; An n-type cladding layer formed on the substrate; An active layer formed on a portion of the n-type cladding layer; A first p-type cladding layer formed on the active layer; A p-type superlattice layer in which nitride semiconductor layers having different energy bands are sequentially stacked on the first p-type cladding layer to form a multilayer structure; A second p-type cladding layer formed on the p-type superlattice layer; A p-type electrode formed on the second p-type cladding layer; And A nitride semiconductor device comprising an n-type electrode formed on the n-type cladding layer in which the active layer is not formed. The method of claim 1, The nitride semiconductor layer having different energy bands constituting the p-type superlattice layer is composed of In _X Al _Y Ga _{1 -X- Y} N (0≤X, 0≤Y, X + Y≤1) composition. , Nitride semiconductor device, characterized in that formed by varying the composition ratio of Al and In. The method of claim 1, In the p-type superlattice layer, the first nitride semiconductor layer higher than the energy band of the p-type cladding layer and the second nitride semiconductor layer lower than the energy band of the p-type cladding layer are alternately stacked one or more times. A nitride semiconductor device, characterized in that formed. The method of claim 1, In the p-type superlattice layer, the first nitride semiconductor layer lower than the energy band of the p-type cladding layer and the second nitride semiconductor layer higher than the energy band of the p-type cladding layer are alternately stacked one or more times. A nitride semiconductor device, characterized in that formed. The method according to claim 3 or 4, A nitride semiconductor device comprising at least one nitride semiconductor layer in which an energy band sequentially increases in either direction between the first nitride semiconductor layer and the second nitride semiconductor layer constituting the p-type superlattice layer. The method of claim 1, The whole or part of the nitride semiconductor layer constituting the p-type superlattice layer is doped with p-type impurities, characterized in that the nitride semiconductor device. The method of claim 6, The dopant concentration of the p-type impurity is a nitride semiconductor device, characterized in that formed differently or uniformly for each position of the nitride semiconductor layer constituting the p-type superlattice layer. The method of claim 1, The first p-type cladding layer is nitride semiconductor device, characterized in that it comprises a separate UDMHy source implanted during growth. The method of claim 1, The nitride semiconductor device further comprises a transparent conductor layer formed between the second p-type cladding layer and the p-type electrode. The method of claim 1, And a n-type superlattice layer having a multilayer structure in which nitride semiconductor layers having different energy bands are sequentially stacked between the n-type cladding layer and the active layer. The method of claim 10, The nitride semiconductor layer having different energy bands constituting the n-type superlattice layer is composed of In _X Al _Y Ga _{1 -X- Y} N (0≤X, 0≤Y, X + Y≤1) composition. , Nitride semiconductor device, characterized in that formed by varying the composition ratio of Al and In. The method of claim 11, In the n-type superlattice layer, the first nitride semiconductor layer higher than the energy band of the n-type cladding layer and the second nitride semiconductor layer lower than the energy band of the n-type cladding layer are alternately stacked one or more times. A nitride semiconductor device, characterized in that formed. The method of claim 11, In the n-type superlattice layer, the first nitride semiconductor layer lower than the energy band of the n-type cladding layer and the second nitride semiconductor layer higher than the energy band of the n-type cladding layer are alternately stacked one or more times. A nitride semiconductor device, characterized in that formed. The method according to claim 12 or 13, And at least one nitride semiconductor layer in which an energy band is sequentially increased in any one direction between the first nitride semiconductor layer and the second nitride semiconductor layer constituting the n-type superlattice layer. The method of claim 10, The whole or part of the nitride semiconductor layer forming the n-type superlattice layer is doped with n-type impurities, characterized in that the nitride semiconductor device. The method of claim 15, The doping concentration of the n-type impurity is a nitride semiconductor device, characterized in that formed differently or uniformly for each position of the nitride semiconductor layer constituting the n-type superlattice layer.

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