JPH118439A - Nitride semiconductor light-emitting device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a laser of simpler structure than usual by a method, wherein a third nitride semiconductor layer which contains aluminum is interposed between an active layer and a nitride semiconductor layer, and an aluminum oxide is included in a part of the third nitride semiconductor layer. SOLUTION: An Al oxide-containing current constriction layer 30 is provided between an active layer 14 and a p-side contact layer or between the active layer 14 and an n-side buffer layer 11. The current constriction layer 30 is composed of a peripheral region (a), which contains Al and Ga oxide and a center region (b) which contains no oxide, wherein the region a is high in resistance, and the region b is kept low in resistance. On the other hand, when the current construction layer 30 is formed on an n-layer side, the peripheral region (a) is set high in resistance, and the center region (b) is turned into an n conductive type. By this setup, a layer high in an Al mixing ratio functions as a current constricting layer or a light-trapping layer, and a laser device of simpler structure than the conventional can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device made of a nitride semiconductor used for a light emitting diode (LED), a laser diode (LD), and the like, and a method of manufacturing the light emitting device.

[0002]

2. Description of the Related Art Nitride semiconductors have just recently been put to practical use in full-color LED displays, traffic signals and the like as materials for high-brightness blue LEDs and pure green LEDs. LEDs used for these various devices have an active layer made of InGaN having a single quantum well structure (SQW) between an n-type nitride semiconductor layer and a p-type nitride semiconductor layer. It has a double hetero structure sandwiched between.
Wavelengths such as blue and green are determined by increasing or decreasing the In composition ratio of the InGaN active layer.

Further, the present applicant has announced for the first time in the world a 410 nm laser oscillation at room temperature under pulse current using this material {for example, Jpn. J. Appl. Phys. 35 (1996) L74,
Jpn.J.Appl.Phys.35 (1996) L217}. This laser device has a double heterostructure having an active layer of a multiple quantum well structure using InGaN, and has a threshold current of 610 mA and a threshold current density of 8.7 kA / cm ^{2 under} the conditions of a pulse width of 2 μs and a pulse period of 2 ms. , 410 nm oscillation. In addition, we developed the improved laser device in Appl.Phys.Lett. 69 (19
96) 1477. This laser device has a structure in which a ridge stripe is formed in a part of a p-type nitride semiconductor layer, and has a pulse width of 1 μs, a pulse period of 1 ms,
At a duty ratio of 0.1%, oscillation at a threshold current of 187 mA, a threshold current density of 3 kA / cm ² , and 410 nm is shown. And we succeeded in continuous oscillation at room temperature for the first time,
Announced. {For example, Nikkei Electronics December 1996
2nd issue technical bulletin, Appl.Phys.Lett.69 (1996) 3034, Appl.P
hys. Lett. 69 (1996) 4056 etc.}
, A continuous oscillation for 27 hours is shown at a threshold current density of 3.6 kA / cm ² , a threshold voltage of 5.5 V, and an output of 1.5 mW. At present, no report has been made worldwide on successful continuous oscillation of a nitride semiconductor laser device other than the present applicant.

[0004]

The laser device has a so-called electrode stripe type structure, in which a current is concentrated on a p-electrode having a stripe width of several μm to cause an active layer below the ridge to emit light. Laser light is emitted from the active layer end surface by causing light emission to resonate on the resonance surface formed on the active layer end surface. In the case of this laser device, a current constriction layer for concentrating current in the active layer is not provided inside the nitride semiconductor layer, and current is concentrated on the stripe-shaped p-electrode. On the other hand, light confinement is performed by using a cladding layer made of a nitride semiconductor having a band gap energy larger than that of the active layer and a ridge structure above the active layer. If the light confinement of the active layer and the current confinement can be performed at the same time, laser oscillation can be realized with a simpler structure than before. Accordingly, an object of the present invention is to provide a novel structure of a laser device mainly composed of a nitride semiconductor and a method of manufacturing the same.

[0005]

According to the present invention, there is provided a nitride semiconductor device comprising: an active layer and a first nitride semiconductor layer doped with an n-type impurity; or an active layer and a p-type impurity doped with an p-type impurity. A third nitride semiconductor layer containing aluminum is formed between the second nitride semiconductor layer and the second nitride semiconductor layer, and a part of the third nitride semiconductor layer contains an oxide of aluminum. . In the present invention, the active layer, the third nitride semiconductor layer, and the first nitride semiconductor layer do not have to be formed in contact with the active layer, the third nitride semiconductor layer, and the second nitride semiconductor layer. May not be formed in contact with the nitride semiconductor layer.

[0006] In the light-emitting element of the present invention, the third nitride semiconductor layer contains more aluminum than the first nitride semiconductor layer and the second nitride semiconductor layer.

Further, according to the method of manufacturing a light emitting device of the present invention, a first nitride semiconductor layer containing an n-type impurity, an active layer, and a second nitride semiconductor containing a p-type impurity are grown on a substrate. A step of growing a third nitride semiconductor layer containing aluminum between the active layer and the first nitride semiconductor layer or between the active layer and the second nitride semiconductor layer After performing the steps A and B, the periphery of the third nitride semiconductor layer is exposed and heated in an atmosphere containing at least oxygen or an atmosphere containing moisture, so that the third nitride semiconductor layer is exposed. C step of oxidizing a part of the layer.

[0008]

FIG. 1 is a schematic cross-sectional view showing one structure of a light emitting device of the present invention. Specifically, FIG. 1 shows a light emitting device cut in a direction perpendicular to a resonance direction of laser light. FIG. As a basic structure, on a GaN substrate 10 grown on a substrate (not shown) made of a material different from the nitride semiconductor, an n-side buffer layer 11 made of Si-doped GaN, N-side cladding layer 12, n-side light guide layer 13 made of Si-doped GaN, active layer 14 having a multiple quantum well structure in which InGaN and GaN are stacked, Mg-doped AlGa
A p-side cap layer 15 made of N, a p-side optical guide layer 16 made of Mg-doped GaN, a p-side cladding layer 17 made of Mg-doped AlGaN,
It has a structure in which a current confinement layer 30 containing Al oxide in part of N and a p-side contact layer 18 made of Mg-doped GaN are stacked. A p-electrode 19 is formed on almost the entire surface of the p-side contact layer 18, and the n-electrode exposed by etching is formed.
An n-electrode 20 is formed on the surface of the side buffer layer 11

The current confinement layer 30 containing Al oxide is formed at any position between the active layer 14 and the p-side contact layer 18 or between the active layer 14 and the n-side buffer layer 11. can do. That is, the active layer and the first nitride semiconductor layer doped with the n-type impurity, or the active layer and the p-type
As long as it is between the second nitride semiconductor layer doped with the type impurity, it can be formed between any layers. The current confinement layer 30
For example, as shown in FIG. 1, it is composed of a region a in a peripheral portion containing Al and Ga oxides and a region b in a central portion not containing oxides. The region a has a high resistance due to the inclusion of the oxide, while the region b has a low resistance (p conductivity type in FIG. 1). On the other hand, when the current confinement layer is formed on the n-layer side, the peripheral area a has high resistance and the central area b has n conductivity type. The area of the layer b is set to 10 μm or less, more preferably 5 μm or less. Similarly, in the case of a surface emitting laser element, it is desirable to adjust the diameter to 10 μmφ or less, preferably to 5 μmφ or less.

The current confinement layer 30 is preferably formed of a nitride semiconductor containing Al, and is preferably formed of Al _x Ga ₁ -xN (0 <X ≦ 1), and preferably has an X value of 0.3 or more. _X Ga
Formed with _1-XN . Further, the film thickness is set to a thickness not less than that the carrier does not tunnel through the current confinement layer.
The film is formed to have a thickness of angstrom or more and 5 μm or less, more preferably 0.1 μm or more and 2 μm or less. 5 μm
If the thickness is larger than this, cracks tend to be easily formed in the current confinement layer, and the growth tends to be difficult.

The current confinement layer 30 includes a carrier confinement layer and
P-side cladding layer 17 as a light confinement layer,
When located at a position close to the electrode 19, the current confinement layer 30
As the name implies, the current injected from the p-electrode 19 is narrowed.
It has an effect of concentrating on a part of the active layer 14. Same
The flow confinement layer 30 is a carrier confinement layer and a light confinement layer
Closer to the substrate 10 side than the n-side cladding layer 12
The same operation is performed when the position is set as described above. Meanwhile, current constriction
Layer 30 is between p-side cladding layer 17 and active layer 14
In this case, the current confinement layer 30 has an active
Has the effect of confining the light emission of the conductive layer. This is the current confinement layer
Al, specifically, Al _TwoO_ThreeHas a refractive index of
This is because the refractive index is smaller than that of the nitride semiconductor. This work
For use, the current confinement layer 30 is composed of the n-side cladding layer 12 and the active layer 1.
4 is the same. Therefore, the conventional light closed
The n-side cladding layer and p-side cladding layer, which were the confining layers, were omitted.
You can also. Also, the light emission of the active layer is closed in a narrow area.
The surface emitting laser element
Oscillation occurs at a low threshold when the element is manufactured.

Further, in the manufacturing method of the present invention, the periphery of the third nitride semiconductor layer is exposed, and the wafer or the element is heated in an atmosphere containing oxygen (including ozone) or an atmosphere containing moisture. It forms by doing. This uses an action in which a nitride semiconductor containing Al is oxidized first from the surroundings. In other words, a nitride semiconductor such as AlN, GaN, and InN was found to be more easily oxidized than AlN before GaN and InN, so that the third nitride semiconductor layer containing a large amount of Al was grown, After exposing the periphery of the third nitride semiconductor layer, heat treatment is performed to oxidize the periphery first and leave the central portion with low resistance, so that the third nitride semiconductor layer is kept at a low current. It acts as a stenosis layer. Therefore, the third nitride semiconductor layer has the highest A among the stacked nitride semiconductor layers constituting the device.
It is desirable to increase the mixed crystal ratio. In FIG. 1, the region containing an oxide in the current blocking layer 30 is indicated by a, but the periphery of the n-side cladding layer 12 and the p-side cladding layer 17 made of another nitride semiconductor containing Al is also a current blocking layer. Although not as large, it contains some oxides.

For exposing the peripheral portion of the third nitride semiconductor layer, for example, etching is used. That is, before the nitride semiconductor wafer is separated into elements, for example, by performing etching to expose the surface of the n-side contact layer where the n-electrode is to be formed, the third nitride layer above the n-type contact layer can be formed. It is possible to simultaneously expose the side surfaces of the object semiconductor layer. In addition, in the case of a surface emitting laser element, the periphery of the third nitride semiconductor layer can be automatically exposed by separating the wafer into laser chips by dicing, scribing, or the like.

[0014]

【Example】

Embodiment 1 Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. A single crystal of GaN is placed on a substrate of sapphire (C-plane) through a buffer layer of GaN.
A GaN substrate 10 having a thickness of μm is prepared. This GaN substrate 10 is set in a reaction vessel, and the temperature is set to 10
The temperature was raised to 50 ° C., and hydrogen was used as a carrier gas, ammonia and TMG (trimethylgallium) were used as source gases, and silane gas was used as an impurity gas.
An n-side buffer layer 11 of 10 ¹⁸ / cm ³ doped GaN is grown to a thickness of 4 μm. This buffer layer
When a light-emitting element having the structure shown in FIG. 1 is manufactured, it also functions as a contact layer for forming an n-electrode. Further, the n-side buffer layer is a buffer layer grown at a high temperature, for example, on a substrate made of a material different from the nitride semiconductor, such as sapphire, SiC, and spinel.
At a low temperature of 0 ° C. or less, GaN, AlN,
It is distinguished from a buffer layer directly grown with a thickness of less than μm.

(N-side cladding layer 12 = strained superlattice layer) Subsequently, n-type Al _0.15 doped with Si at 1 × 10 ¹⁹ / cm ³ using TMA (trimethylaluminum), TMG, ammonia and silane gas at 1050 ° C. the layer made of Ga _{0.8 5} N is grown to the thickness of 40 angstroms, followed by silane gas, stop the TMA, growing a layer made of undoped GaN with a thickness of 40 angstroms.
Then, these two types of layers are alternately laminated by 100 layers, and an n-side cladding layer 12 composed of a strained superlattice having a total film thickness of 0.8 μm is grown.

(N-side light guide layer 13) Subsequently, the silane gas is stopped and the n-side light guide layer 13 made of n-undoped GaN doped with 1 × 10 ¹⁸ / cm ³ of Si at 1050 ° C. has a thickness of 0.1 μm. Grow with. The n-side light guide layer functions as a light guide layer of the active layer, and is formed of GaN, InG
It is desirable to grow aN, and it is usually desirable to grow the film to a thickness of 100 Å to 5 μm, more preferably 200 Å to 1 μm. This layer can also be a strained superlattice layer. In the case of a strained superlattice layer, the band gap energy is larger than that of the active layer and smaller than that of the n-side cladding layer. It is desirable that the n-type impurity concentration of this layer be lower than that of the n-side cladding layer 12.

(Active Layer 14) Next, TMG is used as a raw material gas.
The active layer 14 is grown using TMI and ammonia.
The active layer 14 maintains the temperature at 800 ° C.
A well layer made of n _0.2 Ga _0.8 N is grown to a thickness of 25 Å. Then at the same temperature only changing the molar ratio of TMI, a barrier layer composed of 1 × 10 ¹⁸ / cm ³ doped with In _0.01 Ga _{0 .95} N the Si is grown to the thickness of 50 angstroms. This operation is repeated twice, and finally, an active layer having a multiple quantum well structure (MQW) having a total film thickness of 175 Å in which well layers are stacked is grown. The active layer may be undoped as in this embodiment,
Type impurities and / or p-type impurities may be doped. The impurity may be doped into both the well layer and the barrier layer, or may be doped into either one.

(P-side cap layer 15)
Raise to 50 ° C, TMG, TMA, ammonia, Cp2M
g (cyclopentadienyl magnesium), p-type Al _0.2 Ga doped with Mg at 1 × 10 ²⁰ / cm ³ and having a larger band gap energy than the p-side light guide layer 16
_A p-side cap layer 17 of _0.8 N is grown to a thickness of 300 Å. The lower limit of the thickness of the p-type cap layer 15 is not particularly limited, but is preferably formed to a thickness of 10 Å or more.

(P-side light guide layer 18) Subsequently, Cp2M
g, TMA is stopped, and at 1050 ° C., the band gap energy is smaller than that of the p-side cap layer 15.
A p-side light guide layer 18 of GaN doped with 10 ¹⁹ / cm ³ is grown to a thickness of 0.1 μm. This layer functions as a light guide layer of the active layer, and is preferably made of GaN or InGaN, like the n-type light guide layer 13.
Note that the p-side light guide layer may be a strained superlattice layer. When a strained superlattice layer is used, the band gap energy is larger than that of the active layer and smaller than that of the p-side cladding layer. It is desirable that the p-type impurity concentration of the p-side light guide layer be lower than that of the p-side cladding layer 17.

(P-side cladding layer 17)
P-type Al _0.15 G doped with Mg at 1 × 10 ²⁰ / cm ³
a layer consisting of a _{0.8 5} N is grown to the thickness of 40 Å, followed stopped TMA only, growing a layer of undoped GaN with a thickness of 40 angstroms.
Then, 100 layers of each of these two types are laminated to form a p-side cladding layer 17 composed of a strained superlattice layer having a total film thickness of 0.8 μm.

(Current Blocking Layer 30) Next, at 1050 ° C., M
A second buffer layer made of GaN doped with g at 1 × 10 ²⁰ / cm ³ is grown to a thickness of 100 Å (not shown). This GaN layer acts as a buffer layer when growing a current blocking layer containing Al. Subsequently, p-type Al _0.4 Ga doped with Mg at 1 × 10 ²⁰ / cm ^3.
_A current blocking layer 30 of _0.6 N is grown to a thickness of 0.5 μm. In the state as grown in this way, it has not yet functioned as a current blocking layer, but in this embodiment, it is called a current blocking layer.

(P-side contact layer 18) Finally, 105
P-type GaN doped with 2 × 10 ²⁰ / cm ^{3 of} Mg at 0 ° C.
The p-side contact layer 18 is grown to a thickness of 150 Å. The p-side contact layer 18 can be composed of p-type In _x Al _Y Ga _{1 -XYN} (0 ≦ X, 0 ≦ Y, X + Y ≦ 1), and is preferably Ga doped with Mg.
If N, the most preferable ohmic contact with the p electrode 21 can be obtained.

The wafer on which the nitride semiconductor has been grown as described above is placed in a reaction vessel in a nitrogen atmosphere at 700.degree.
Annealing is performed at a temperature of ° C. to further reduce the resistance of the layer doped with the p-type impurity.

After annealing, the wafer is taken out of the reaction vessel, and as shown in FIG. 1, the uppermost p-side contact layer 18 is etched by an RIE apparatus to form the side surface of the current confinement layer 30 and the n-electrode 20. The surface of the n-side buffer layer 11 to be exposed is exposed.

Next, N is formed on almost the entire surface of the p-side contact layer 18.
A p electrode 19 made of i and Au is formed. On the other hand, an n-electrode 20 made of Ti and Al is formed in a stripe shape on the surface of the n-side buffer layer 11 that has been exposed earlier. After the electrodes are formed, the sapphire substrate of the wafer is removed by polishing, and G
The back surface of the aN substrate is exposed.

After polishing, the wafer is put into an annealing apparatus, and annealed in an oxygen atmosphere at 300 ° C. for several hours to oxidize the vicinity of the current confinement layer 30 to act as a current confinement layer.

After oxidation, the wafer is cut into bars in a direction parallel to the stripes of the n-electrode 20. When cut into bars, the cross-sectional view in the direction parallel to the short sides of the bars is the same as FIG. On the other hand, the bar was cleaved in the direction perpendicular to the stripe-shaped n-electrode 20, a resonator was formed on the cleaved surface, and each electrode was wire-bonded to perform laser oscillation at room temperature. Laser oscillation for more than an hour was confirmed.

Example 2 In Example 1, after growing the p-side light guide layer, Mg was added to 1 × 10 ^{20 in the same} manner as in Example 1.
A current confinement layer made of an Al _0.4 Ga _0.6 N layer doped with / cm ³ is grown to a thickness of 0.5 μm. In the first embodiment, the second buffer layer made of GaN grown before growing the current confinement layer is not grown in this embodiment because the p-side light guide layer is a buffer layer.

After growing the current confinement layer, the p-side contact layer made of Mg-doped GaN is directly grown to a thickness of 500 Å without growing the p-side cladding layer. In the case of this embodiment, the p-side cladding layer is not grown because the current confinement layer functions as a light confinement layer. After that, when a laser device was manufactured in the same manner as in Example 1, a laser device having substantially the same characteristics as in Example 1 was obtained.

Example 3 In Example 1, after growing the n-side buffer layer, silane gas, TM
Using G, TMA, and ammonia, Si was added at 1 × 10 ¹⁹ / cm
^A current blocking layer made of ^3- doped Al _0.4 Ga _0.6 N is grown to a thickness of 0.5 μm. Next, the n-side light guide layer is grown directly on the current blocking layer without growing the n-side cladding layer 12. Thereafter, a nitride semiconductor was grown on the current blocking layer in the same manner as in Example 1, and a laser device was fabricated in the same manner. As a result, a laser device having substantially the same characteristics as in Example 1 was obtained. Was done.

Embodiment 4 FIG. 2 is a schematic sectional view showing the structure of a device according to another embodiment of the present invention, and specifically shows the structure of a surface emitting laser device. This embodiment will be described below with reference to FIG.

A substrate 10 'made of Si-doped GaN with a thickness of 150 μm grown on a substrate made of spinel (111) is prepared.
Using a VPE method, as in Example 1, 1 × 1 of Si
A 40 Å layer of n-type Al _0.2 Ga _0.8 N doped with 0 ¹⁹ / cm ³ and undoped GaN
Layers of 40 Angstroms and 25
An n-side cladding layer 12 'having a strained superlattice structure, which is alternately stacked, is grown to a thickness of 0.2 μm.

Next, a well layer of undoped In _0.2 Ga _0.8 N, 25 Å, and undoped In _0.2 Ga _0.8 N
_A barrier layer made of _0.01 Ga _0.95 N and 50 Å are alternately laminated twice each, and a well layer is finally laminated to form a multiple quantum well structure (MQ having a total thickness of 175 Å).
An active layer 14 'made of W) is grown.

Next, at 1050 ° C., Mg was added to 1 × 10 ²⁰ /
A current blocking layer 30 made of p-type Al _0.4 Ga _0.6 N doped with cm ³ is grown to a thickness of 0.5 μm. In this embodiment, since the active layer containing InGaN is a buffer layer, the second buffer layer of the first embodiment is not grown.

Subsequently, Mg was added in the same manner as in Example 1.
× and 10 ²⁰ / cm ³ doped with p-type Al _{0 .2} Ga _0.8 consisting N layer 40 Å, an undoped (undope) G
A p-side cladding layer 17 'having a strained superlattice structure, in which layers of aN are alternately stacked with 40 angstroms 25 times each, is grown to a thickness of 0.2 μm.

Finally, at 1050 ° C., Mg was added to 1 × 10 ²⁰ / cm
P-side contact layer 1 made of ^3- doped p-type GaN
8 'is grown to a thickness of 200 angstroms.

The wafer on which the nitride semiconductor has been grown as described above is taken out of the reaction vessel, the spinel substrate is polished and removed, and then a protective film is formed on the back surface of the GaN substrate 10 ′. Etching is performed on the unformed portion to form a hole 100 having a diameter of 20 μm as shown in FIG. The depth of the hole 100 depends on the bottom of the hole and the n-side cladding layer 3.
Is adjusted to be 0.5 μm. When a surface emitting laser device is made of a nitride semiconductor as in this embodiment, a hole 100 is provided on the back surface of the substrate, and a reflecting mirror is provided at the bottom of the hole. By providing this hole 100. The cavity length of the active layer is shortened, and the laser oscillates at a low threshold value to easily obtain a single mode laser beam. p-side reflector 2
It is desirable that the distance between 0 and the n-side reflecting mirror 21 be adjusted to 10 μm or less, more preferably 5 μm or less, and most preferably 3 μm or less. The lower limit is not particularly limited, but is adjusted to 100 Å or more, preferably to the emission wavelength of the active layer, usually to 380 nm or more. 10
If the length is longer than μm, the loss increases, the threshold value increases, and the device life tends to be shortened.

After the formation of the hole 100, the wafer is transferred to a CVD apparatus, and an n-side reflecting mirror 21 made of a dielectric multilayer film of SiO ₂ and TiO ₂ is formed at the bottom of the hole 100 as shown in FIG. On the other hand, a protective film having a predetermined shape is also formed on the surface of the p-side contact layer 18 ', and as shown in FIG.
Is formed. These reflectors are 410
It is designed to have a reflectance of 80% or more for the emission wavelength of nm.

Next, a ring-shaped n-electrode 2010 made of Ti / Al surrounding the n-side reflecting mirror 21 is formed on the back surface of the GaN substrate 10 ′, while the uppermost p-side contact layer 8 is formed.
Almost the entire surface except for the second reflecting mirror 12 is Ni / Au.
After the formation of the p-electrode 9, the GaN substrate 10 ′ is cleaved by a scriber and separated into 200 μm square chips.

Further, the chip contains 30% of water.
In an annealing apparatus at 0 ° C., the substrate is allowed to stand in the air for more than ten hours to oxidize the vicinity of the p-side cladding layer 17 ′ as shown in FIG. 2 to act as a current confinement layer. The surface-emitting laser device fabricated as described above is compared with a conventional electrode stripe type nitride semiconductor laser device.
It shows room temperature continuous oscillation of 408 nm at a current of about 1/30,
Lifespan was 1 minute or more.

[0041]

According to the present invention, a nitride semiconductor layer having a high Al mixed crystal ratio is made to exist in a laminated semiconductor and its periphery is oxidized so that a layer having a high Al mixed crystal ratio becomes a current confinement layer and a light confining layer. Since it functions as a confinement layer, a laser element can be obtained with a simple structure as compared with the related art. Further, the method of the present invention is one method for obtaining a third nitride semiconductor having an oxide in the vicinity of the periphery, and the light emitting device of the present invention is not necessarily limited to the method by this manufacturing method. ,
The present invention can be applied to a light emitting device made of another nitride semiconductor such as an LED device and a super luminescent diode.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing the structure of a laser device according to one embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a structure of a laser device according to another embodiment of the present invention.

[Explanation of symbols]

 10, 10 'GaN substrate 11 ... n-side buffer layer 12, 12' ... n-side cladding layer 13 ... n-side light guide layer 14, 14 '... active layer ... P-side cap layer 16... P-side light guide layer 17, 17 ′... P-side cladding layer 18, 18 ′... P-side contact layer 30, 30 ′.・ Current blocking layer

Claims (3)

[Claims] 1. An active layer and a first doped n-type impurity.
A third nitride semiconductor layer containing aluminum is formed between the third nitride semiconductor layer or the active layer and the second nitride semiconductor layer doped with a p-type impurity. A nitride semiconductor light-emitting device, wherein a part of the nitride semiconductor layer contains an aluminum oxide. 2. The semiconductor device according to claim 1, wherein the third nitride semiconductor layer contains more aluminum than the first nitride semiconductor layer and the second nitride semiconductor layer. Nitride semiconductor light emitting device. 3. An A step of growing a first nitride semiconductor layer containing an n-type impurity, an active layer, and a second nitride semiconductor containing a p-type impurity on an upper portion of the substrate. 1
Step B, step A, and step B of growing a third nitride semiconductor layer containing aluminum were performed between the first nitride semiconductor layer and the second nitride semiconductor layer or between the active layer and the second nitride semiconductor layer. Thereafter, a step of exposing a part of the third nitride semiconductor layer by oxidizing a part of the third nitride semiconductor layer by exposing a periphery of the third nitride semiconductor layer and heating in an atmosphere containing at least oxygen or an atmosphere containing moisture. A method for manufacturing a nitride semiconductor light emitting device, comprising: