JP2000244071A - Semiconductor light-emitting element and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting element of low threshold current density, high light-emitting efficiency and high reliability, and a method for manufacturing it. SOLUTION: In a semiconductor laser element 100, a low-temperature buffer layer 2, an n-GaN layer 3, an n-optical clad layer 4, an n-light guide layer 5, an n-MQW light-emitting layer 6, a p-block layer 7, a p-light guide layer 8 and a p-optical clad layer 9 are laminated in this order over a sapphire substrate 1. The p-optical clad layer 9 of a ridge part is removed from the surface to a specified depth, so that a stripe-like recessed part is formed. A current constriction layer 10 is formed on the p-optical clad layer 9 except the stripe-like recessed part, and a p-contact layer 11 is formed on the stripe-like recessed part of the p-optical clad layer 9 and the current constriction layer 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a group III-V nitride semiconductor such as BN (boron nitride), GaN (gallium nitride), AlN (aluminum nitride) or InN (indium nitride) or a mixed crystal thereof. The present invention relates to a semiconductor light emitting device having a compound semiconductor layer made of a nitride semiconductor) and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, GaN-based semiconductor light-emitting devices such as light-emitting diodes and semiconductor laser devices that emit blue or violet light have been put into practical use.

FIG. 7 is a schematic sectional view showing an example of a conventional GaN-based semiconductor laser device. As shown in FIG. 7, the semiconductor laser device 400 has a c (0
On the (001) plane, a low-temperature buffer layer 62 made of undoped GaN and an n-contact layer 6 made of n-GaN
3, n-light cladding layer 64 made of n-Al _0.1 Ga _0.9 N, n-light guiding layer 65 made of n-GaN, n-M
QW (multiple quantum well) light emitting layer 66, p-Al _0.1 Ga
_A p-block layer 67 made of _0.9 N, a p-light guide layer 68 made of p-GaN, a p-light cladding layer 69 made of p-Al _0.1 Ga _0.9 N, and a first layer made of p-GaN
Are sequentially stacked. Predetermined regions of the first p-contact layer 70 and the p-light cladding layer 69 are etched to expose the p-light cladding layer 69, thereby forming a ridge. As described above, the semiconductor laser device 400 has a ridge waveguide structure.

A current confinement layer 71 is stacked on the first p-contact layer 70 except for a central stripe region. Further, a second p-contact layer 72 is stacked on the first p-contact layer 70 and the current confinement layer 71.

An insulating film 73 is formed except for a central region on the second p-contact layer 72, and a p-electrode 51 is formed on the central region of the p-contact layer 72 and on the insulating film 73. Is formed. Further, n
A part of the region up to the contact layer 63 is removed by etching, and the n-electrode 5 is formed on the exposed n-contact layer 63;
0 is formed.

In the semiconductor laser device 400, the distribution of the refractive index occurs in the horizontal direction of the n-MQW light emitting layer 66 due to the formation of the ridge portion. Further, the current is narrowed by the current narrowing layer 71, and a current injection region is formed in the ridge portion. By utilizing such a distribution of the refractive index and the constriction of the current, confinement of light in a horizontal direction, that is, control of a transverse mode is performed.

When manufacturing the semiconductor laser device 400,
In the crystal growth apparatus, the layers 62 to 70 are crystal-grown in order on a sapphire substrate (wafer) 61 by MOCVD (metal organic chemical vapor deposition).

Subsequently, the wafer is taken out of the crystal growing apparatus, and a Ni mask is formed in a central region on the first p-contact layer 70 in the air. Using this Ni mask, the first p-contact layer 70 and the p-optical cladding layer 69 are etched to form a ridge. After that, the Ni mask is removed.

Next, the exposed first p-contact layer 7
The surfaces of the 0 and p-light cladding layers 69 are washed with an organic solvent, an acid, or the like to remove dirt on the surfaces. Then the first
Then, an SiO ₂ mask is formed in the central stripe region on the p-contact layer 70, and the process returns to the crystal growth apparatus.

[0010] In the crystal growth apparatus, the first p-contact layer 70 on the region excluding the SiO ₂ mask and the p-
On the optical cladding layer 69, an n-current confinement layer 71 is grown. Thereafter, the wafer is taken out of the crystal growing apparatus again,
The SiO ₂ mask formed on the first p-contact layer 70 is removed.

The wafer is returned to the crystal growth apparatus, and the exposed first p-contact layer 70 and the current confinement layer 71 are
A second p-contact layer 72 is grown thereon.

Further, SiO ₂ is formed using a mask pattern.
A film 73 is formed, and a partial region from the SiO ₂ film 73 to the n-contact layer 63 is etched. Finally, an n-electrode 50 and a p-electrode 51 are respectively formed in predetermined regions,
Separation into elements by cleavage.

[0013]

SUMMARY OF THE INVENTION As described above, semiconductors
The ridge portion of the laser element 400 and the current confinement layer 71 are formed.
In the step of forming,
Take out eha, SiO _TwoMask formation and removal
To do. In such a process, the first p-contact
A surface level is generated on the surface of the layer 70.

When a surface level is generated in the first p-contact layer 70 in the ridge portion, the first p-contact layer 70 in the current injection region is formed.
The conductivity at the interface between contact layer 70 and second p-contact layer 72 decreases. In addition, the second p-contact layer 72 regrown on the first p-contact layer 70 having a surface level has poor crystallinity. Thereby, the second
It becomes difficult to increase the hole concentration of the p-contact layer 72 to a certain level or more, and the mobility of holes decreases. Therefore, the concentration of holes involved in radiative recombination decreases.

Due to these factors, the device resistance of the semiconductor laser device 400 increases, and the reactive current not related to light emission increases. Thereby, the luminous efficiency of the semiconductor laser device 400 decreases. Further, when the element resistance and the reactive current increase, the element temperature rises, so that dislocations grow in the crystal of the semiconductor laser element 400. Thereby, the semiconductor laser element 400 is deteriorated, so that the reliability of the element is reduced and the life is shortened.

Further, light loss increases due to the first p-contact layer 70 having a surface level and the second p-contact layer 72 having poor crystallinity. Therefore,
The threshold current density of the semiconductor laser device 400 increases.

An object of the present invention is to provide a semiconductor light emitting device having a low threshold current density, high luminous efficiency and high reliability, and a method for manufacturing the same.

[0018]

A semiconductor light emitting device according to a first aspect of the present invention includes a light emitting layer and a first nitride semiconductor layer including at least one of indium, gallium, aluminum and boron. A stripe-shaped current injection region is provided thereon, and a first current injection region in the current injection region is provided.
A predetermined depth from the surface of the nitride-based semiconductor layer is removed to form a stripe-shaped recess, and at least one of indium, gallium, aluminum, and boron is formed on at least the first nitride-based semiconductor layer in the stripe-shaped recess. A second nitride-based semiconductor layer containing

In the semiconductor light emitting device according to the present invention,
By removing a predetermined depth from the surface of the first nitride-based semiconductor layer in the current injection region to form a stripe-shaped concave portion, the surface level of the first nitride-based semiconductor layer is removed, and the surface level of the first nitride-based semiconductor layer is removed. A second nitride-based semiconductor layer is formed on the regrown surface of the first nitride-based semiconductor layer from which the position has been removed. Therefore, a decrease in conductivity at the interface between the first nitride-based semiconductor layer and the second nitride-based semiconductor layer is suppressed, and the element resistance is reduced.

Further, since the second nitride-based semiconductor layer is formed on the regrown surface from which surface levels have been removed, the crystallinity is good. For this reason, the carrier concentration of the second nitride-based semiconductor layer can be increased, and the mobility of carriers in the second nitride-based semiconductor layer can be improved. As a result, the carrier concentration involved in the radiative recombination increases, and the reactive current is reduced.

Further, since the element resistance and the reactive current are reduced, the rise of the element temperature is suppressed, and the deterioration of the element is prevented. As a result, a semiconductor light emitting device having high reliability and long life can be obtained.

Further, since the surface level of the first nitride-based semiconductor layer in the current injection region is removed and the crystallinity of the second nitride-based semiconductor layer is good, light loss is reduced, The threshold current density is reduced.

As described above, a semiconductor light emitting device having a low threshold current density, high luminous efficiency and high reliability can be obtained.

A ridge is formed in a region of a predetermined width of the first nitride semiconductor layer, a stripe-shaped recess is formed on the upper surface of the ridge, and the first nitride semiconductor layer on both sides of the stripe recess is formed. A current confinement layer may be formed on the region, and a second nitride-based semiconductor layer may be formed on the first nitride-based semiconductor layer in the stripe-shaped recess.

In this case, a current is confined and injected into the stripe-shaped recess formed in the ridge portion of the first nitride-based semiconductor layer by the current confinement layer, and an optical waveguide is formed in the light emitting layer below the stripe-shaped recess. It is formed.

In manufacturing such a semiconductor light emitting device, a step of forming a ridge portion in a region of a predetermined width of the first nitride-based semiconductor layer and a step of forming a current confinement layer on the first nitride-based semiconductor layer Is formed, a surface level is generated in the first nitride-based semiconductor layer. However, the first of the ridges
By forming a stripe-shaped recess in the nitride-based semiconductor layer, the surface level of the first nitride-based semiconductor layer is removed in the stripe-shaped recess, and the stripe-shaped recess in which the surface level has been removed is formed. A second nitride-based semiconductor layer is formed on the first nitride-based semiconductor layer and the current confinement layer. Thereby, the surface state of the first nitride-based semiconductor layer in the current injection region is reduced, and the crystallinity of the second nitride-based semiconductor layer is improved.

The first nitride semiconductor layer is composed of a lower layer including a light emitting layer and an upper layer formed on the lower layer in a region wider than the current injection region, and a stripe is formed on the upper surface of the upper layer. A current confinement layer is formed on the upper layer and the lower layer on both sides of the stripe-shaped depression, and a second nitride-based semiconductor layer is formed on the current confinement layer and on the upper layer in the stripe-shaped depression. It may be formed.

In this case, the current is confined and injected into the stripe-shaped concave portion formed in the upper layer of the first nitride-based semiconductor layer by the current confining layer, and the optical waveguide is formed in the light emitting layer below the stripe-shaped concave portion. It is formed.

In manufacturing such a semiconductor light emitting device, in a step of forming a current confinement layer on the first nitride-based semiconductor layer, a surface state is formed on an upper layer of the first nitride-based semiconductor layer. Occurs. However, a stripe-shaped recess is formed in the upper layer of the first nitride-based semiconductor layer,
The surface level of the upper layer portion of the first nitride-based semiconductor layer is removed in the stripe-shaped recess, and the second nitride layer is formed on the upper layer and the current confinement layer in the striped recess from which the surface level has been removed. An object-based semiconductor layer is formed. Thereby, the surface state of the first nitride-based semiconductor layer in the current injection region is reduced, and the crystallinity of the second nitride-based semiconductor layer is improved.

The wide region of the lower layer may be removed to a certain depth, and the upper layer may be formed on the removed region. In this case, the surface state generated in the lower layer in the step of forming the upper layer on the lower layer of the first nitride-based semiconductor layer is removed, and the upper layer is formed on the lower layer from which the surface state has been removed. It is formed. Thereby, the surface state of the lower layer is reduced, and the crystallinity of the upper layer is improved.

A current confinement layer is formed on the region of the first nitride semiconductor layer on both sides of the stripe-shaped recess, and a second current confinement layer is formed on the current confinement layer and on the first nitride semiconductor layer in the stripe-shaped depression. May be formed.

In this case, a current is confined and injected into the stripe-shaped recess formed in the first nitride-based semiconductor layer by the current confinement layer, and an optical waveguide is formed in the light emitting layer below the stripe-shaped recess. .

In manufacturing such a semiconductor light emitting device, surface levels are generated in the first nitride semiconductor layer in the step of forming a current confinement layer on the first nitride semiconductor layer. However, the surface level of the first nitride-based semiconductor layer was removed in the stripe-shaped concave portion by forming the stripe-shaped concave portion in the first nitride-based semiconductor layer, and the surface level was removed. A second nitride-based semiconductor layer is formed on the first nitride-based semiconductor layer and the current confinement layer. Thereby, the surface state of the first nitride-based semiconductor layer in the current injection region is reduced, and the crystallinity of the second nitride-based semiconductor layer is improved.

According to a second aspect of the invention, there is provided a method of manufacturing a semiconductor light emitting device, comprising: forming a first nitride semiconductor layer including a light emitting layer and including at least one of indium, gallium, aluminum and boron; Forming a stripe-shaped recess by etching from the surface of the first nitride-based semiconductor layer to a certain depth in the current-injected region, and forming indium on at least the first nitride-based semiconductor layer in the stripe-shaped recess. Forming a second nitride-based semiconductor layer containing at least one of gallium, aluminum, and boron.

In the method for manufacturing a semiconductor light-emitting device according to the present invention, a stripe-shaped concave portion is formed by etching a predetermined depth from the surface of the first nitride-based semiconductor layer in the stripe-shaped current injection region. A surface state of the first nitride-based semiconductor layer is removed, and a second nitride-based semiconductor layer is formed on a regrown surface of the first nitride-based semiconductor layer from which the surface state has been removed.

In the semiconductor light emitting device manufactured by the manufacturing method according to the present invention, a decrease in conductivity at the interface between the first nitride semiconductor layer and the second nitride semiconductor layer is suppressed in the current injection region. Thus, the element resistance is reduced.

Further, since the second nitride-based semiconductor layer is formed on the regrown surface of the first nitride-based semiconductor layer from which the surface levels have been removed, the crystal of the second nitride-based semiconductor layer is formed. The property becomes good. Therefore, the carrier concentration of the second nitride-based semiconductor layer can be increased, and the mobility of carriers in the second nitride-based semiconductor layer can be improved.
As a result, the carrier concentration involved in the radiative recombination increases, and the reactive current is reduced.

Further, since the element resistance and the reactive current are reduced, the rise in the element temperature is suppressed and the deterioration of the element is prevented. As a result, a semiconductor light emitting device having high reliability and long life can be obtained.

Further, since the surface level of the first nitride-based semiconductor layer in the current injection region is removed and the crystallinity of the second nitride-based semiconductor layer is good, light loss is reduced, The threshold current density is reduced.

As described above, a semiconductor light emitting device having a low threshold current density, high luminous efficiency and high reliability can be obtained.

A ridge portion is formed in a region of a predetermined width of the first nitride-based semiconductor layer, a stripe-shaped concave portion is formed on the upper surface of the ridge portion, and the first nitride-based semiconductor layer on both sides of the stripe-shaped concave portion is formed. A current confinement layer may be formed on the region, and a second nitride-based semiconductor layer may be formed on the first nitride-based semiconductor layer in the stripe-shaped recess.

In this case, a current is confined and injected into the stripe-shaped recess formed in the ridge portion of the first nitride-based semiconductor layer by the current confinement layer, and an optical waveguide is formed in the light emitting layer below the stripe-shaped recess. Is done.

In the method of manufacturing a semiconductor light emitting device as described above, the steps of forming a ridge portion on the first nitride-based semiconductor layer and forming a current confinement layer on the first nitride-based semiconductor layer Then, a surface level is generated in the first nitride-based semiconductor layer. However, by forming a stripe-shaped recess in the first nitride-based semiconductor layer of the ridge portion,
The surface level of the first nitride-based semiconductor layer is removed in the stripe-shaped recess, and the first nitride-based semiconductor layer and the current confinement layer in the striped recess from which the surface state has been removed are removed. 2 are formed. Thereby, the surface state of the first nitride-based semiconductor layer in the current injection region is reduced, and the crystallinity of the second nitride-based semiconductor layer is improved.

A first nitride semiconductor layer is formed by laminating an upper layer wider than the current injection region on the lower layer including the light emitting layer, and a stripe-shaped recess is formed on the upper surface of the upper layer. The current confinement layer may be formed on the upper layer and the lower layer on both sides of the concave shape, and the second nitride-based semiconductor layer may be formed on the current confinement layer and on the upper layer in the stripe-shaped concave portion.

In this case, the current is confined and injected into the stripe-shaped recess formed in the upper layer of the first nitride-based semiconductor layer by the current confinement layer, and an optical waveguide is formed in the light emitting layer below the stripe-shaped recess. Is done.

In the method for manufacturing a semiconductor light emitting device as described above, the step of forming a current confinement layer on the upper layer of the first nitride-based semiconductor layer includes the steps of: Surface levels occur. However, by forming the stripe-shaped recess in the upper layer of the first nitride-based semiconductor layer, the surface level of the upper layer portion of the first nitride-based semiconductor layer in the stripe-shaped recess is removed, and this surface level is reduced. A second nitride-based semiconductor layer is formed on the upper layer and the current confinement layer in the striped concave portions from which the positions have been removed. Thereby, the surface state of the first nitride-based semiconductor layer in the current injection region is reduced, and the crystallinity of the second nitride-based semiconductor layer is improved.

Further, the wide region of the lower layer may be etched to a certain depth, and the upper layer may be formed on the etched region. In this case, the surface state generated in the lower layer in the step of forming the upper layer on the lower layer of the first nitride-based semiconductor layer is removed, and the upper layer is formed on the lower layer from which the surface state has been removed. Form. Thereby, the surface state of the lower layer is reduced, and the crystallinity of the upper layer is improved.

A current confinement layer is formed on the region of the first nitride-based semiconductor layer on both sides of the stripe-shaped recess, and a second current confinement layer is formed on the current confinement layer and on the first nitride-based semiconductor layer in the stripe-shaped recess. May be formed.

In this case, a current is confined and injected into the stripe-shaped recess formed in the first nitride-based semiconductor layer by the current confinement layer, and an optical waveguide is formed in the light emitting layer below the stripe-shaped recess. .

In such a method of manufacturing a semiconductor light emitting device, a surface level is generated in the first nitride-based semiconductor layer in the step of forming a current confinement layer on the first nitride-based semiconductor layer. However, by forming the stripe-shaped recess in the first nitride-based semiconductor layer, the surface state of the first nitride-based semiconductor layer is removed in the stripe-shaped recess,
A second nitride-based semiconductor layer is formed on the first nitride-based semiconductor layer from which the surface level has been removed and on the current confinement layer. Thereby, the surface state of the first nitride-based semiconductor layer in the current injection region is reduced, and the crystallinity of the second nitride-based semiconductor layer is improved.

According to a third aspect of the invention, there is provided a method of manufacturing a semiconductor light emitting device, comprising: forming a first nitride semiconductor layer including a light emitting layer and including at least one of indium, gallium, aluminum and boron; Etching from the surface of the first nitride-based semiconductor layer to a certain depth in the current-injected region, and forming at least indium, gallium, aluminum and boron on the first nitride-based semiconductor layer in the etched region. Forming a second nitride-based semiconductor layer including at least one of them.

In the method for manufacturing a semiconductor light-emitting device according to the present invention, the first nitride-based semiconductor layer is etched from the surface of the first nitride-based semiconductor layer to a predetermined depth in the stripe-shaped current injection region. A surface state of the layer is removed, and a second nitride-based semiconductor layer is formed on the regrown surface of the first nitride-based semiconductor layer from which the surface state has been removed. Thereby, the surface state of the first nitride-based semiconductor layer in the current injection region is reduced, and the crystallinity of the second nitride-based semiconductor layer is improved.

[0053]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a semiconductor laser device will be described as an example of a semiconductor light emitting device according to the present invention.

FIGS. 1 and 2 are schematic sectional views showing a first example of a method for manufacturing a semiconductor laser device according to the present invention.

As shown in FIG. 1A, in an MOCVD apparatus (metal organic chemical vapor deposition apparatus), undoped Ga is deposited on the c (0001) plane of a sufficiently cleaned sapphire substrate 1.
Low-temperature buffer layer 2 made of N and having a thickness of 20 nm, thickness of 4 μm
m-n-GaN layer 3, n-Al _0.1 Ga _0.9 N 700 nm thick n-light cladding layer 4, n-GaN 200 nm thick n-light guide layer 5, n-MQW light emitting layer 6 20 nm thick made of p-Al _0.1 Ga _0.9 N
P-block layer 7 having a thickness of 200 n made of p-GaN
An m-p-light guide layer 8 and a 700 nm-thick p-light cladding layer 9 made of p-Al _0.1 Ga _0.9 N are sequentially grown.

In this case, the n-type dopant is
Si is used, n-GaN layer 3, n-optical cladding layer
4 and the n-light guide layer 5 have an electron concentration of 5 ×
10 ¹⁸cm^-3, 7 × 10¹⁷cm^-3And 6 × 10¹⁷cm
^-3It is. Also, using Mg as a p-type dopant
The p-block layer 7, the p-light guide layer 8 and the p-
The hole concentration of the optical cladding layer 9 is 7 × 10¹⁷cm
^-3, 1 × 10¹⁸cm^-3And 7 × 10¹⁷cm^-3It is.

The n-MQW light emitting layer 6 is made of n-In _0.03 Ga
Four 20 nm thick quantum barrier layers of _0.97 N and I
It has a multiple quantum well structure in which three quantum well layers each having a thickness of 15 nm and made of n _0.13 Ga _0.87 N are alternately stacked.

Subsequently, the wafer is taken out from the MOCVD apparatus, and a Ni mask (not shown) is formed on the central region of the p-light cladding layer 9 in the air. This Ni
Using the mask, a region of the p-light cladding layer 9 excluding the Ni mask is etched by a reactive ion etching method using chlorine ions. Thus, a ridge is formed in the p-light cladding layer 9 and the Ni mask is removed.
After depositing a SiO ₂ mask (not shown) by sputtering on the stripe region at the center of the ridge, the wafer is returned to the MOCVD apparatus.

Next, as shown in FIG.
On the p-light cladding layer 9 except for the region of the iO ₂ mask,
A current confinement layer 10 made of n-Al _0.3 Ga _0.7 N is formed. After that, the wafer is taken out of the MOCVD apparatus,
The above-mentioned SiO ₂ mask is removed with an aqueous solution of hydrogen fluoride. In this way, the stripe region 40 at the center of the p-light cladding layer 9 is exposed. In this case, a surface level is formed in the exposed stripe region 40 of the p-light cladding layer 9.

Further, as shown in FIG. 1C, the exposed striped region 40 of the p-light cladding layer 9 is etched to a depth of 20 nm using a high temperature potassium hydroxide aqueous solution. The etching depth in this case is p
-A value converted from the etching time based on the etching rate of the optical cladding layer 9 of 100 ° / min.

In this manner, a stripe-shaped concave portion having a depth of 20 nm is formed in the stripe-shaped region 40 of the ridge portion of the p-light cladding layer 9, and the regrown surface 41 is exposed in the stripe-shaped concave portion. In this case, surface levels have been removed from the exposed regrown surface 41.

After the stripe-shaped concave portions are formed in the p-light cladding layer 9 as described above, the wafer is again subjected to MOCVD.
Return to device. Further, as shown in FIG. 2D, a hole concentration of 1 × 10 ¹⁸ cm is formed on the regrown surface 41 and the current confinement layer 10 in the stripe-shaped concave portions of the p-light cladding layer 9.
A p-contact layer 11 having a thickness of 1 μm and made of ^-3 p-GaN is formed. Thereafter, the wafer is placed in a nitrogen atmosphere at 600 ° C. to activate the p-type dopant.

Further, as shown in FIG. 2E, a 500 nm thick SiO ₂ film 12 is deposited on the region of the p-contact layer 11 excluding the p-electrode formation region by sputtering.

Subsequently, a photoresist having an opening in a region excluding an n-electrode formation region is patterned to have a thickness of 50 nm.
Deposit 0 nm of Ni. By removing Ni on the photoresist together with the photoresist, regions other than the n-electrode formation region are covered with a Ni mask. As shown in FIG. 2F, using the Ni mask, the portions from the SiO ₂ film 12 in the n-electrode formation region to the n-contact layer 3 are etched by a reactive ion etching method using chlorine ions. In this case, the etching depth is 2 μm. After exposing a part of the n-contact layer 3 in this manner, the Ni mask is removed.

Further, as shown in FIG. 2G, a Ti film having a thickness of 100 nm, an Al film having a thickness of 200 nm, and an Au film having a thickness of 500 nm are sequentially deposited on the exposed n-contact layer 3, An electrode 50 is formed. Further, a photoresist having an opening in a p-electrode formation region is patterned, and a Pt film having a thickness of 300 nm and a
nm of Au film is sequentially deposited. Pt on photoresist
The p-electrode 51 is formed by removing the film and the Au film together with the photoresist.

Finally, the layers 2 to 12 are cleaved together with the sapphire substrate 1 on a plane parallel to the short side of the n-electrode 50. Thus, a width of 10 μm and a length of 500 μm
A semiconductor laser device 100 having a ridge waveguide structure having m resonators is manufactured.

In the semiconductor laser device 100, Si
Since the current is confined by the O ₂ film 12 and the current confinement layer 10, a current injection region is formed in the stripe-shaped concave portion in the ridge portion.

In this embodiment, the regrown surface 41 from which the surface level has been removed is exposed by etching the striped region 40 of the p-light cladding layer 9 in the ridge portion having the surface level. The p-contact layer 11 is formed on the growth surface 41. Therefore, in the current injection region, it is possible to suppress a decrease in conductivity at the interface between the p-light cladding layer 9 and the p-contact layer 11.
Therefore, the device resistance of the semiconductor laser device 100 is reduced.

The p-contact layer 11 re-grown on the re-grown surface 41 from which the surface levels have been removed as described above.
The crystallinity is improved as compared with the case where regrowth is performed on the stripe region 40 of the p-light cladding layer 9 having the surface level. Therefore, the hole concentration of the p-contact layer 11 can be increased, and the mobility of the holes can be increased. This increases the concentration of holes involved in light emission recombination, so that the reactive current is reduced and the semiconductor laser device 100 with high light emission efficiency is obtained.

Further, in the semiconductor laser device 100, since the device resistance and the reactive current can be reduced as described above, it is possible to suppress an increase in the device temperature. Therefore, deterioration of the device can be prevented, and the semiconductor laser device 100 having high reliability and a long life can be obtained.

Further, since the surface level of the regrown surface 41 of the p-light cladding layer 9 in the ridge portion is reduced and the crystallinity of the p-contact layer 11 is improved, light loss is reduced. Therefore, the threshold current density can be reduced.

FIGS. 3 and 4 are schematic sectional views showing a second example of the method for manufacturing a semiconductor laser device according to the present invention.

As shown in FIG. 3A, on a sapphire substrate 1, a low-temperature buffer layer 2, an n-GaN layer 3, an n-light cladding layer 4, an n-light guide layer 5, an n-MQW light-emitting layer 6, p
Growing the blocking layer 7, the p-light guiding layer 8 and the first p-contact layer 9a in this order. In addition, each layer 2-9a
The structure and growth method of each layer 2 shown in FIG.
9 is as described above.

Subsequently, the wafer is taken out of the MOCVD apparatus, and a selective growth SiO ₂ mask 15 having an opening in a predetermined region is deposited on the first p-light cladding layer 9a by sputtering in the air.

Next, as shown in FIG. 3B, the first p-light cladding layer 9a in the opening of the selective growth SiO ₂ mask 15 is formed to a depth of 5
Etch to nm. In this way, a stripe-shaped recess having a depth of 5 nm is formed in the first p-type optical cladding layer 9a, and the first regrowth surface 42 is exposed in the stripe-shaped recess. In this case, surface levels are removed from the exposed first regrowth surface 42. Thereafter, the wafer is returned to the MOCVD apparatus again.

Further, as shown in FIG. 3C, on the first regrown surface 42, a second p-light cladding layer 9b made of p-Al _0.1 Ga _0.9 N and having a thickness of 700 nm is formed.
A 300 nm-thick first p-contact layer 11a made of GaN is sequentially grown. In this case, the second p-light cladding layer 9b and the first p-contact layer 11a are
It is difficult to grow on the SiO ₂ mask 15 for selective growth. Therefore, the second p-light cladding layer 9b and the first p-light cladding layer 9b are formed on the stripe-shaped concave portions of the first p-light cladding layer 9a.
The contact layer 11a can be selectively grown. In this way, a ridge portion composed of the second p-light cladding layer 9b and the first p-contact layer 11a is formed.

Subsequently, the wafer is taken out from the MOCVD apparatus, and as shown in FIG. 3D, the selective growth SiO ₂ mask 15 is removed with an aqueous hydrogen fluoride solution. further,
After a SiO ₂ mask (not shown) is formed on a predetermined region of the first p-contact layer 11a in the ridge portion, the wafer is returned to the MOCVD apparatus.

[0078] Next, as shown in FIG. 4 (e), SiO ₂
N-Al _0.3 Ga _0.7 N is formed on the region other than the mask formation region.
The current confinement layer 10 is grown and taken out of the MOCVD apparatus again. Further, the SiO ₂ mask is removed with an aqueous solution of hydrogen fluoride to expose a predetermined region of the first p-contact layer 11a. In this case, the exposed first p-contact layer 11a has a surface level. Further, the exposed first p-contanct layer 11a is
Etching is performed to a depth of 20 nm with a high-temperature aqueous potassium hydroxide solution. In this way, a stripe-shaped recess having a depth of 20 nm is formed in the first p-contact layer 11a, and the second regrown surface 43 is exposed in the stripe-shaped recess. In this case, surface levels are removed from the exposed second regrowth surface 43.

Subsequently, the wafer is returned to the MOCVD apparatus again, and as shown in FIG. 4F, on the second regrowth surface 43 in the stripe-shaped recess of the first p-contact layer 11a and the current confinement layer. On the second p-contact layer 11
grow b. Thereafter, the wafer is placed in a nitrogen atmosphere at 600 ° C. to activate the p-type dopant.

Next, as shown in FIG. 4 (g), on the second p-contact layer 11b except for the p-electrode formation region,
The SiO ₂ film 12 is deposited by the same method as (e).

Further, as shown in FIG.
By the same method as (f), a part of the n-contact layer 3 is exposed, and the n-electrode 50 is formed on the exposed n-contact layer 3. Further, a p-electrode 51 is formed on a predetermined region of the second p-contact layer 11b by a method similar to that shown in FIG. Finally, the semiconductor laser device 200 having a ridge waveguide structure having a resonator having a width of 10 μm and a length of 500 μm is manufactured by cleavage.

In the semiconductor laser device 200, Si
Since the current is confined by the O ₂ film 12 and the current confinement layer 10, a current path is formed in the stripe-shaped concave portion in the ridge portion.

In the present embodiment, predetermined regions of the first p-light cladding layer 9a and the first p-contact layer 11a are etched to form stripe-shaped recesses, thereby removing the surface states. The first and second regrown surfaces 42 and 43 are exposed, and a second p-light cladding layer 9b and a second p-contact layer 11b are formed on the first and second regrown surfaces 42 and 43. I do. Therefore, in the current injection region, the interface between the first p-light cladding layer 9a and the second p-light cladding layer 9b in the ridge portion, and the first p-contact layer 11a and the second p-contact layer are formed. It is possible to suppress a decrease in conductivity at the interface with 11b. Therefore, the device resistance of the semiconductor laser device 200 is reduced.

Further, the second p-light cladding layer 9b and the second p-contact regrown on the first and second regrown surfaces 42 and 43 from which the surface levels have been removed as described above. The crystallinity of the layer 11b is improved as compared with the case where the layer 11b is regrown on the first p-light cladding layer 9a having the surface level and the first p-contact layer 11a. Therefore, the hole concentration of the second p-light cladding layer 9b and the second p-contact layer 11b can be increased, and the mobility of holes can be increased. Thus, the concentration of holes involved in light emission recombination increases, so that the reactive current is reduced, and the semiconductor laser device 200 with high light emission efficiency is obtained.

As described above, in the semiconductor laser device 200, the device resistance and the reactive current can be reduced, so that the device has high reliability and a long life.

The re-grown surfaces 42, 43 of the first p-light cladding layer 9a and the first p-contact layer 11a.
Is reduced, and the crystallinity of the second p-light cladding layer 9b and the second p-contact layer 11b is improved, so that light loss is reduced. It is possible to reduce the density.

FIGS. 5 and 6 are schematic sectional views showing a third example of the method for manufacturing a semiconductor laser device according to the present invention.

As shown in FIG. 5A, in a MOCVD apparatus, c (00)
01) plane, a low-temperature buffer layer 22 and an n-GaN layer 2
3, n-light cladding layer 24, n-light guide layer 25, n-light
An MQW light emitting layer 26, a p-block layer 27, a p-light guide layer 28, and a first p-contact layer 29 are sequentially grown. The configuration and growth method of each of the layers 22 to 28 are as described above for each of the layers 2 to 8 in FIG. The first p-contact layer 29 is made of p-GaN having a hole concentration of 7 × 10 ¹⁷ cm ⁻³ and has a thickness of 20 × 10 ¹⁷ cm ^−3.
0 nm. Take out the wafer from MOCVD equipment,
In the air, a selective growth SiO ₂ mask 30 having a thickness of 2 μm is formed in a predetermined region on the first p-contact layer 29. Thereafter, the wafer is returned to the MOCVD apparatus again.

Further, as shown in FIG.
Long SiO_TwoFirst p-conductor excluding mask 30 formation region
On the tact layer 29, the electron concentration is 3 × 10¹⁹cm^-3N-
Al _0.3Ga_0.7N of about 0.5 μm in thickness
The current confinement layer 31 is grown.

Next, the wafer is taken out of the MOCVD apparatus, and as shown in FIG. 5C, the selective growth SiO ₂ mask 30 is removed with an aqueous solution of hydrogen fluoride. In this manner, a predetermined region of the first p-contact layer 29 is exposed. In this case, the exposed first p-contact layer 29
Has a surface level. Further, the exposed first p-
The contact layer 29 is etched to a depth of 20 nm with a high-temperature aqueous solution of potassium hydroxide. In this way, a stripe-shaped recess having a depth of 20 nm is formed in the first p-contact layer 29, and the regrowth surface 44 is exposed in the stripe-shaped recess. In this case, surface levels have been removed from the regrown surface 44.

The wafer is returned to the MOCVD apparatus again, and FIG.
As shown in (d), a thickness 500 of p-Al _0.1 Ga _0.9 N is formed on the regrown surface 44 in the stripe-shaped concave portion of the first p-contact layer 29 and on the current confinement layer 31.
A p-light cladding layer 32 of nm and a second p-contact layer 33 of 1 μm in thickness and made of p-GaN are sequentially grown. The hole concentration of the p-light cladding layer 32 is 7 × 1.
0 ¹⁷ cm ⁻³ , and the concentration of holes in the second p-contact layer 33 is 1 × 10 ¹⁸ cm ⁻³ .

Thereafter, the wafer is placed in a nitrogen atmosphere at 600 ° C. to activate the p-type dopant.

Further, as shown in FIG.
By the same method as (f), the second p-contact layer 3 is formed.
Part of the region from 3 to n-contact layer 23 is etched to expose a predetermined region of n-contact layer 23.

Subsequently, as shown in FIG.
An n-electrode 50 is formed on the exposed n-contact layer 23 and a p-electrode 51 is formed on the second p-contact layer 33 in the same manner as in (g). Finally, the semiconductor laser device 300 having a self-aligned structure having a cavity having a width of 10 μm and a length of 500 μm is formed by cleavage.
Is prepared.

In the semiconductor laser device 300, since the current is confined by the current confinement layer 31, the current confinement layer 3
A current injection region is formed in the stripe-shaped concave portion of the first p-contact layer 29 between the two.

In this example, the regrown surface 44 from which the surface level has been removed is formed by etching the stripe-shaped region of the first p-contact layer 29 having the surface level to form a stripe-shaped recess. Exposure is performed, and the p-light cladding layer 32 is formed on the regrown surface 44. Therefore, in the current injection region, the first p-contact layer 2
It is possible to suppress a decrease in conductivity at the interface between the layer 9 and the p-light cladding layer 32. Therefore, the device resistance of the semiconductor laser device 300 is reduced.

Also, the p-light cladding layer 32 regrown on the regrown surface 44 from which the surface levels have been removed as described above.
The crystallinity is improved as compared with the case where regrowth is performed on the first p-contact layer 29 having a surface level. For this reason, it is possible to increase the concentration of holes in the p-light cladding layer 32 and increase the mobility of holes. This increases the concentration of holes involved in light emission recombination, so that the reactive current is reduced and the semiconductor laser device 300 with high light emission efficiency is obtained.

As described above, in the semiconductor laser device 300, since the device resistance and the reactive current can be reduced, a device having high reliability and a long life can be obtained.

Further, since the surface level of the regrown surface 44 of the first p-contact layer 29 is reduced and the crystallinity of the p-light cladding layer 32 is improved, light loss is reduced. Therefore, the threshold current density can be reduced.

The above-described semiconductor laser devices 100 and 2
In 00 and 300, the striped regions of the layers 9, 11a, 29 and 9a having surface levels are etched to a depth of 20 nm and 5 nm in order to expose the regrown surfaces 40 to 44 from which the surface levels have been removed. However, the etching depth may be any other value as long as the striped region having the surface level can be removed. The fact that the depth of the stripe-shaped recess affects the FFP (far-field image), and that excessive etching results in the regrown surfaces 40-44.
In consideration of, for example, damage to the substrate, the etching depth is preferably 5 nm or more. Further, it is preferable that the upper limit of the etching depth is such that it does not penetrate the layer to be etched. In this case, the etching depth is a value converted from the etching time based on the etching rate of each of the layers 9, 11a, 29, and 9a.

The semiconductor laser devices 100, 200,
In 300, the current confinement layers 10, 31 are n-Al
_0.3 Ga _0.7 N, but other than SiO
_The current confinement layers 10 and 31 may be composed of _two films or Si ₃ N ₄ films. In this case, the SiO 2
Current confinement layers 10 and 31 made of _two films or Si ₃ N ₄ films
Each layer 11a, 11b, 32 is difficult to grow on. Therefore, the respective layers 11, 11b, 32 may be grown on the current confinement layers 10, 31 using the lateral growth technique, and the respective layers 11, 11b, 32 may be formed on the entire surface of the wafer. Or,
On the current confinement layers 10 and 31, the respective layers 11, 11b and 32
Need not be formed.

In the above description, the semiconductor laser device 10
Each of the layers constituting 0, 200, and 300 is made of a nitride-based semiconductor containing Al, Ga, and In. In addition, each layer may be made of a nitride-based semiconductor containing boron.

The semiconductor laser devices 100, 200,
In 300, the case where the n-type semiconductor layer is formed on the sapphire substrates 1 and 21 is described, but the semiconductor light emitting device according to the present invention is a semiconductor laser device in which the p-type semiconductor layer is formed on the sapphire substrates 1 and 21. It is applicable also in. In this case, a predetermined region of the n-type semiconductor layer having a surface level is etched to form a stripe-shaped concave portion,
The semiconductor layer is regrown on the regrown surface from which surface levels exposed in the stripe-shaped concave portions have been removed.

In FIG. 1B, the current confinement layer 1
0 may be formed only on the side surface so as not to be on the upper surface of the ridge portion, and the stripe-shaped region 40 may be the entire upper surface of the ridge portion. In this case, in FIG. 1C, since the stripe-shaped region 40 on the upper surface of the ridge portion is etched to a predetermined depth, no stripe-shaped concave portion is formed, and the entire ridge portion becomes thin.

In the above description, the case where the present invention is applied to a semiconductor laser device has been described, but the present invention is also applicable to other semiconductor light emitting devices such as light emitting diodes.

[0106]

EXAMPLES The GaN-based semiconductor laser devices shown in Examples 1 to 9 and Comparative Examples 1 to 3 had an optical output of 4 mW.
The driving current at the time of was measured.

Example 1 A semiconductor laser device 100 was manufactured by the method for manufacturing a semiconductor laser device shown in FIGS. 1 (a) to 2 (g). In this case, a predetermined region of the p-light cladding layer 9 in the ridge portion was etched to a depth of 20 nm to expose the regrown surface 41.

When the drive current was measured using the semiconductor laser device 100 of Example 1, the drive current was 250 mA.

Example 2 A semiconductor laser device has the same structure as that of the semiconductor laser device 100 of Example 1 except that a stripe-shaped concave portion having a depth of 10 nm is formed in a predetermined region of the p-light cladding layer 9 in the ridge portion. A semiconductor laser device was manufactured. The semiconductor laser device of the second embodiment has the p-type
A predetermined region of the optical cladding layer 9 was etched to a depth of 10 nm to form a stripe-shaped recess, and the semiconductor laser device 100 of the first embodiment was formed except that the regrowth surface 41 was exposed in the stripe-shaped recess. It was manufactured by the same manufacturing method as that described above.

The drive current was measured using the semiconductor laser device of Example 2 and found to be 250 mA.

Example 3 A semiconductor laser device has the same structure as that of the semiconductor laser device 100 of Example 1 except that a stripe-shaped concave portion having a depth of 5 nm is formed in a predetermined region of the p-light cladding layer 9 in the ridge portion. A semiconductor laser device was manufactured. In the semiconductor laser device of the third embodiment, a predetermined region of the p-light cladding layer 9 in the ridge portion is etched to a depth of 5 nm to form a stripe-shaped recess, so that the regrown surface 41 is formed in the stripe-shaped recess. The semiconductor laser device 100 was manufactured by the same manufacturing method as that of the semiconductor laser device 100 of Example 1 except that the semiconductor laser device 100 was exposed.

The drive current was measured using the semiconductor laser device of Example 3 and found to be 244 mA.

[Comparative Example 1] In Comparative Example 1, the semiconductor laser device 10 of Example 1 was manufactured except that no stripe-shaped concave portion was formed in the p-light cladding layer 9 in the ridge portion.
A semiconductor laser device having the same structure as that of the semiconductor laser device was manufactured.
Such a semiconductor laser device of Comparative Example 1 was manufactured by the same manufacturing method as the semiconductor laser device 100 of Example 1 except for the following points.

In the semiconductor laser device of Comparative Example 1,
The etching of the p-light cladding layer 9 for forming the stripe-shaped concave portions was not performed, and the p-type of the ridge portion shown in FIG.
After cleaning the surface of the region 40 of the optical cladding layer 9, the p-contact layer 11 was regrown on the surface of this region 40.

When the drive current was measured using the semiconductor laser device of Comparative Example 1, the drive current was 315 mA.

Example 4 A semiconductor laser device 200 was manufactured by the method for manufacturing a semiconductor laser device shown in FIGS. 3 (a) to 4 (h). In this case, a predetermined region of the first p-contact layer 11a in the ridge portion was etched to a depth of 20 nm to expose the second regrown surface 43.

When the drive current was measured using the semiconductor laser device 200 of Example 4, the drive current was 253 mA.

Fifth Embodiment A structure similar to that of the semiconductor laser device 200 of the fourth embodiment except that a stripe-shaped concave portion having a depth of 10 nm is formed in a predetermined region of the first p-contact layer 11a in the ridge portion. Was fabricated. In the semiconductor laser device of the fifth embodiment, a predetermined region of the first p-contact layer 11a in the ridge portion is etched to a depth of 10 nm to form a stripe-shaped concave portion, thereby regrowing in the stripe-shaped concave portion. Except that the surface 43 was exposed,
It was manufactured by the same manufacturing method as that of the 00

The drive current was measured using the semiconductor laser device of Example 5 and found to be 250 mA.

Example 6 A structure similar to that of the semiconductor laser device 200 of Example 4 except that a stripe-shaped concave portion having a depth of 5 nm was formed in a predetermined region of the first p-contact layer 11a in the ridge portion. Was fabricated. In the semiconductor laser device according to the sixth embodiment, the predetermined region of the first p-contact layer 11a in the ridge portion has a depth of 5 mm.
The semiconductor laser device 200 of Example 4 was formed except that the regrowth surface 43 was exposed in the stripe-shaped recess by forming the stripe-shaped recess by etching to nm.
It was manufactured by the same manufacturing method as that described above.

When the drive current was measured using the semiconductor laser device of Example 6, the drive current was 252 mA.

[Comparative Example 2] In Comparative Example 2, except that the first p-contact layer 11a in the ridge portion was not formed with a stripe-shaped concave portion, the same as in the semiconductor laser device 200 of Example 4 was used. A semiconductor laser device having a structure was manufactured. Such a semiconductor laser device of Comparative Example 2
Except for the following points, the semiconductor laser device 200 of the fourth embodiment
It was manufactured by the same manufacturing method as that described above.

In the semiconductor laser device of Comparative Example 2,
P-contact layer 11 for forming stripe-shaped concave portions
After the surface of the first p-contact layer 11a in the ridge portion is cleaned without performing the etching of
-The contact layer 11b was regrown.

When the drive current was measured using the semiconductor laser device of Comparative Example 2, the drive current was 320 mA.

Example 7 A semiconductor laser device 300 was manufactured by the method for manufacturing a semiconductor laser device shown in FIGS. 5 (a) to 6 (f). In this case, the first
A predetermined region of the p-contact layer 29 was etched to a depth of 20 nm to expose the regrown surface 44.

When the drive current was measured using the semiconductor laser device of Example 7, the drive current was 248 mA.

[Embodiment 8] First p-contact layer 29
A semiconductor laser device having a structure similar to that of the semiconductor laser device 300 of Example 7 was manufactured except that a stripe-shaped concave portion having a depth of 10 nm was formed in a predetermined region. In the semiconductor laser device of Example 8 described above, a predetermined region of the first p-contact layer 29 is etched to a depth of 10 nm to form a stripe-shaped recess, so that the regrown surface 44 is formed in the stripe-shaped recess. The semiconductor laser device 300 was manufactured by the same manufacturing method as that of the semiconductor laser device 300 of the seventh embodiment except that it was exposed.

When the drive current was measured using the semiconductor laser device of Example 8, the drive current was 255 mA.

[Embodiment 9] First p-contact layer 29
A semiconductor laser device having the same structure as that of the semiconductor laser device 300 of Example 7 was manufactured except that a stripe-shaped concave portion having a depth of 5 nm was formed in a predetermined region. In the semiconductor laser device of the ninth embodiment, a predetermined region of the first p-contact layer 29 is etched to a depth of 5 nm to form a stripe-shaped recess, thereby exposing the regrown surface 44 in the stripe-shaped recess. Example 7 except that
It was manufactured by the same manufacturing method as that of the semiconductor laser device 300 of FIG.

When the drive current was measured using the semiconductor laser device of Example 9, the drive current was 250 mA.

[Comparative Example 3] In Comparative Example 3, the semiconductor laser device 300 of Example 7 was used except that no stripe-shaped concave portion was formed in the first p-contact layer 29.
A semiconductor laser device having the same structure as described above was manufactured. Such a semiconductor laser device of Comparative Example 3 was manufactured by the same manufacturing method as that of the semiconductor laser device 300 of Example 7, except for the following points.

In the semiconductor laser device of Comparative Example 3,
After etching the surface of the first p-contact layer 29 without performing etching of the first p-contact layer 29 for forming the stripe-shaped concave portions, the p-light cladding layer 32 is regrown on this surface. I let it.

When the drive current was measured using the semiconductor laser device of Comparative Example 3, the drive current was 300 mA.

In the first to ninth embodiments, the layers 9, 11 a, and 29 having surface levels are etched to form stripe-shaped concave portions, so that the regrown surfaces 41 and 43 from which the surface levels have been removed are formed. , 44 are exposed, and the layers 11, 11b, 32 are regrown on the regrown surfaces 41, 43, 44. On the other hand, in Comparative Examples 1 to 3, each layer 9, 11a, 29 having a surface state was not etched, and each layer 1, 11a, 29 having a surface state was directly formed on each layer 9, 11a, 29.
1, 11b, 32 are regrown. Therefore, Embodiment 1
In the semiconductor laser devices of Nos. To 9, the device resistance and the reactive current are reduced as compared with the semiconductor laser devices of Comparative Examples 1 to 3. Therefore, in the semiconductor laser devices of Examples 1 to 9, an optical output of 4 mW was obtained with a lower drive current than the semiconductor laser devices of Comparative Examples 1 to 3.

[Brief description of the drawings]

FIG. 1 is a schematic process sectional view showing a first example of a method for manufacturing a semiconductor laser device according to the present invention.

FIG. 2 is a schematic process sectional view showing a first example of a method for manufacturing a semiconductor laser device according to the present invention.

FIG. 3 is a schematic process sectional view showing a second example of the method for manufacturing a semiconductor laser device according to the present invention.

FIG. 4 is a schematic process sectional view showing a second example of the method for manufacturing a semiconductor laser device according to the present invention.

FIG. 5 is a schematic process sectional view showing a third example of the method for manufacturing a semiconductor laser device according to the present invention.

FIG. 6 is a schematic process sectional view showing a third example of the method for manufacturing a semiconductor laser device according to the present invention.

FIG. 7 is a schematic sectional view showing an example of a conventional semiconductor laser device.

[Explanation of symbols]

1,21,61 Sapphire substrate 2,22,62 Low-temperature buffer layer 3,23,63 n-GaN layer 4,24,64 n-optical cladding layer 5,25,65 n-optical guiding layer 6,26,66 n -MQW light emitting layer 7, 27, 67 p-blocking layer 8, 28, 68 p-light guiding layer 9, 9a, 9b, 32, 69 p-optical cladding layer 10, 31, 71 current confinement layer 11, 11a, 11b , 29, 33, 70, 72 p-
Contact layer 12, 73 SiO ₂ film 41, 42, 43, 44 Regrowth surface 50 n electrode 51 p electrode 100, 200, 300, 400 Semiconductor laser device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5F041 AA03 AA24 AA44 CA04 CA05 CA34 CA40 CA46 CA65 CA74 CB03 5F073 AA13 AA20 AA45 AA51 AA55 AA74 CB05 CB07 EA23 EA28 EA29

Claims (11)

[Claims] 1. A stripe-shaped current injection region is provided on a first nitride-based semiconductor layer including a light-emitting layer and including at least one of indium, gallium, aluminum, and boron. 1 is removed from the surface of the nitride-based semiconductor layer to a certain depth to form a stripe-shaped recess, and at least indium, gallium, aluminum, and boron are formed on the first nitride-based semiconductor layer in the stripe-shaped recess. A semiconductor light emitting device, wherein a second nitride-based semiconductor layer including at least one is formed. 2. A ridge portion is formed in a region of a predetermined width of the first nitride-based semiconductor layer, the stripe-shaped concave portion is formed on an upper surface of the ridge portion, and the first concave portions on both sides of the stripe-shaped concave portion are formed. A current confinement layer is formed on the region of the nitride-based semiconductor layer, and the second nitride-based semiconductor layer is formed on the first nitride-based semiconductor layer in the stripe-shaped recess. The semiconductor light emitting device according to claim 1, wherein 3. The first nitride-based semiconductor layer includes a lower layer including the light emitting layer, and an upper layer formed on the lower layer in a region wider than the current injection region. The stripe-shaped concave portion is formed on the upper surface of the upper layer, a current confinement layer is formed on the upper layer and the lower layer on both sides of the stripe-shaped concave portion, and a current confinement layer is formed on the current constriction layer and in the stripe-shaped concave portion. 2. The semiconductor light emitting device according to claim 1, wherein said second nitride-based semiconductor layer is formed on said upper layer. 4. The semiconductor light emitting device according to claim 3, wherein said wide region of said lower layer is removed to a certain depth, and said upper layer is formed on said removed region. 5. A method according to claim 1, wherein the first portions on both sides of the stripe-shaped recess are provided.
A current confinement layer is formed on the region of the nitride-based semiconductor layer of
2. The semiconductor light emitting device according to claim 1, wherein said second nitride-based semiconductor layer is formed on said current confinement layer and on said first nitride-based semiconductor layer in said stripe-shaped recess. 6. A step of forming a first nitride-based semiconductor layer including a light-emitting layer and including at least one of indium, gallium, aluminum, and boron; and the first nitride in a stripe-shaped current injection region. Forming a stripe-shaped concave portion by etching from the surface of the material-based semiconductor layer to a predetermined depth; and forming at least indium, gallium, aluminum, and boron on the first nitride-based semiconductor layer in the stripe-shaped concave portion. A method for manufacturing a semiconductor light emitting device, further comprising a step of forming a second nitride-based semiconductor layer including one. 7. A ridge portion is formed in a region of a predetermined width of the first nitride-based semiconductor layer, the stripe-shaped concave portion is formed on an upper surface of the ridge portion, and the first concave portions on both sides of the stripe-shaped concave portion are formed. Forming a current confinement layer on the region of the nitride-based semiconductor layer, and forming the second nitride-based semiconductor layer on the first nitride-based semiconductor layer in the stripe-shaped recess. The method for manufacturing a semiconductor light emitting device according to claim 6. 8. The first nitride semiconductor layer is formed by laminating an upper layer wider than the current injection region on a lower layer including the light emitting layer, and the stripe is formed on an upper surface of the upper layer. Forming a current confining layer on the upper layer and the lower layer on both sides of the stripe-shaped concave portion, and forming the second confining layer on the current confining layer and on the upper layer in the stripe-shaped concave portion. 7. The method according to claim 6, wherein the nitride-based semiconductor layer is formed. 9. The method according to claim 8, wherein the wide area of the lower layer is etched to a certain depth, and the upper layer is formed on the etched area. 10. A current confinement layer is formed on a region of the first nitride semiconductor layer on both sides of the stripe-shaped recess,
7. The semiconductor light-emitting device according to claim 6, wherein the second nitride-based semiconductor layer is formed on the current confinement layer and on the first nitride-based semiconductor layer in the stripe-shaped recess. Method. 11. A step of forming a first nitride-based semiconductor layer including a light-emitting layer and including at least one of indium, gallium, aluminum, and boron; and forming the first nitride-based semiconductor layer in a stripe-shaped current injection region. Etching to a certain depth from the surface of the nitride-based semiconductor layer; and at least one of indium, gallium, aluminum and boron on the first nitride-based semiconductor layer in the etched region. A method for manufacturing a semiconductor light emitting device, further comprising a step of forming a nitride-based semiconductor layer.