JP2007242718A - Semiconductor laser element and its fabrication process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor laser element exhibiting high reliability by suppressing the occurrence of COD even when it is driven under severe conditions. <P>SOLUTION: In the semiconductor laser element 1 having a window region 23 including a mixed crystal portion formed through diffusion of group III holes, and a non-window region 24 on the window region 23 having an active layer 15 of quantum well structure where a mixed crystal portion is formed by providing a film for absorbing a predetermined atom and accelerating diffusion of group III holes, a layer in the vicinity of the active layer 15 is doped with impurities occupying a group V site. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes a window region including a mixed crystal portion formed by diffusion of group III vacancies and a non-window region having an active layer having a quantum well structure, and absorbs predetermined atoms to form group III vacancies. The present invention relates to a semiconductor laser device in which an accelerating film for promoting diffusion is provided on a window region to form a mixed crystal portion and a method for manufacturing the semiconductor laser device.

  Conventionally, in a semiconductor laser element that oscillates laser light by amplifying light generated by recombination of carriers in an active layer, the light emitting end face is deteriorated due to strong light density, which is called COD (Catastrophic Optical Damage) May cause damage. As a countermeasure, it has been proposed to provide a window region that absorbs less laser light as compared to the inside of the active layer by increasing the energy band gap at the light emitting end face.

  In recent years, with regard to the formation of the window region of a GaAs-based semiconductor laser element, an accelerating film formed corresponding to the window region and promoting diffusion of Ga and a suppression film formed corresponding to the non-window region and suppressing Ga diffusion. There has been proposed a technique using an IFVD (Impurity Free Vacancy Disordering) method in which a predetermined heat treatment is performed after the deposition and a region corresponding to the window region is mixed (see Patent Document 1).

Japanese Patent Laid-Open No. 7-122816

  However, even a window region mixed using the IFVD method sometimes absorbs laser light having a wavelength corresponding to higher-order energy oscillation. For this reason, when the semiconductor laser element is driven under severe conditions, the semiconductor laser element deteriorates due to the generation of COD, and there is a problem that a highly reliable semiconductor laser element cannot be obtained.

  The present invention has been made in view of the above-described drawbacks of the prior art, and provides a semiconductor laser element that suppresses the generation of COD and has high reliability even when driven under severe conditions. Objective.

  In order to solve the above-described problems and achieve the object, a semiconductor laser device according to the present invention includes a window region including a mixed crystal portion formed by diffusion of a group III vacancy and an active layer having a quantum well structure. In the semiconductor laser device, the active layer includes: a non-window region having a non-window region, wherein a promoting film that absorbs predetermined atoms and promotes diffusion of the group III vacancies is provided on the window region. An impurity occupying a group V site is doped in a layer in the vicinity of.

  The semiconductor laser device according to the present invention is characterized in that the impurity does not self-diffusion.

  The semiconductor laser device according to the present invention is characterized in that C is doped in a layer near the active layer.

  According to another aspect of the present invention, there is provided a semiconductor laser device comprising: a guide layer formed on a side where a p-type clad is laminated on the active layer; and a clad formed on a side where a p-type clad is laminated on the active layer. C is doped to at least the active layer side of the layer.

  The semiconductor laser device according to the present invention is characterized in that C is doped at least on the active layer side of a contact layer formed for injecting holes into the active layer.

  The semiconductor laser device according to the present invention has a ridge structure.

  The semiconductor laser device according to the present invention includes a current non-injection layer provided between the clad layer or the contact layer and confining a current injected from the outside and supplying the active layer to the active layer. The contact layer includes a first layer on which a current confinement layer is formed, a second layer that is regrown after performing a surface cleaning process at 650 ° C. or higher after the formation of the current confinement layer, or a 650 ° C. or higher layer. And a second layer formed by performing regrowth in a temperature range.

  In the semiconductor laser device according to the present invention, a difference between an energy band gap in the window region and an energy band gap in the non-window region is 50 meV or more.

  In addition, a method of manufacturing a semiconductor laser device according to the present invention includes a window region including a mixed crystal portion formed by diffusion of group III vacancies and a non-window region having an active layer having a quantum well structure. In the method of manufacturing a laser element, a promotion film forming step of forming a promotion film on the window region that absorbs predetermined atoms and promotes diffusion of the group III vacancies; and a group V site in the vicinity of the active layer And an impurity-containing layer forming step of forming a layer doped with the occupied impurities.

  In the method for manufacturing a semiconductor laser device according to the present invention, the impurity-containing layer forming step forms a layer doped with C.

  In the method of manufacturing a semiconductor laser device according to the present invention, the impurity-containing layer forming step includes a guide layer provided on a side where a p-type cladding is laminated on the active layer, and a p-type for the active layer. Any one of at least the active layer side of the clad layer provided on the laminating side and at least the active layer side of the contact layer formed to inject holes into the active layer A layer is formed.

  According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor laser device, comprising: a current non-injection layer provided between the cladding layer and the contact layer and confining a current injected from the outside to supply the active layer; Including an injection layer forming step, wherein the impurity-containing layer forming step forms a first layer of the cladding layer on which a current non-injection layer is provided or a first layer of the contact layer on which a current non-injection layer is provided After the first layer forming step and the current non-injection layer forming step, a regrowth treatment after the surface cleaning treatment of 650 ° C. or higher or a regrowth treatment in a temperature range of 650 ° C. or higher is performed, and the second layer of the clad layer Or a second layer forming step of forming a second layer of the contact layer.

  In addition, the semiconductor laser device manufacturing method according to the present invention includes a heat treatment step of diffusing the group III vacancies at a heat treatment temperature of 900 ° C. or higher to crystallize the window region.

According to the present invention, the layer adjacent to the active layer is doped with an impurity occupying a group V site, so that the deterioration of mixed crystallization in the window region and the suppression of mixed crystallization in the non-window region are reduced. And can increase the difference between the energy band gap in the window region and the energy band gap in the non-window region, thereby suppressing COD generation and high reliability even when driven under harsh conditions. It is possible to realize a semiconductor laser element having the same.

  A semiconductor laser element formed by using the IFVD method according to an embodiment of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiments. In the description of the drawings, the same parts are denoted by the same reference numerals. Further, the drawings are schematic, and it should be noted that the relationship between the thickness and width of each layer, the ratio of each layer, and the like are different from the actual ones. Also in the drawings, there are included portions having different dimensional relationships and ratios.

(Embodiment 1)
First, the semiconductor laser device according to the first embodiment will be described. In the semiconductor laser device according to the first embodiment, C is doped as an impurity in a layer formed to inject holes into the active layer. FIG. 1 is a perspective view of the semiconductor laser device according to the first embodiment, FIG. 2-1 is a cross-sectional view of the semiconductor laser device 1 shown in FIG. 1, and FIG. It is a longitudinal cross-sectional view of the semiconductor laser element shown.

  As shown in FIG. 1, the semiconductor laser device 1 according to the first embodiment has a ridge structure that narrows the current in a stripe shape, and a high reflection film 2 is formed on the reflection side of the laser beam 4, and the laser A low reflection film 3 is formed on the light emission side. The laser light generated inside the semiconductor laser element 1 and the laser light reflected by the high reflection film 2 are transmitted through the low reflection film 3 and emitted to the outside.

  Next, the structure of the semiconductor laser device 1 shown in FIG. 1 will be described with reference to FIGS. 2-1 and 2-2. As shown in FIGS. 2A and 2B, the semiconductor laser device 1 includes an n-buffer layer 12, an n-cladding layer 13, an n-guide layer 14, an active layer on a substrate 11 that is an n-type GaAs substrate. The layer 15, the p-guide layer 16, the p-cladding layer 17, the p-contact layer 18, and the insulating layer 19 are sequentially stacked. In the semiconductor laser device 1, the upper electrode 20 is formed on the p-contact layer 18 and the lower electrode 21 is formed on the lower portion of the substrate 11. Further, the p-guide layer 16 formed on the active layer 15 on the side where the p-type cladding is laminated, the p-cladding layer 17 formed on the side where the active layer 15 is laminated with the p-type cladding, and the active layer The p-contact layer 18 formed for injecting holes into the semiconductor layer is doped with C as an impurity. As shown in FIGS. 2-1 and 2-2, the semiconductor laser device 1 has a ridge structure that narrows the current injected into the active layer 15 in a stripe shape and functions as an optical waveguide along the stripe. The mesa shape in which the upper layer of the p-cladding layer 17 and the layer region including the p-contact layer 18 are narrowed in the direction perpendicular to the laser beam emission direction is processed. The semiconductor laser element 1 is provided with a window region 23 that absorbs less laser light than the non-window region 24 on the light emitting end face. The window region 23 includes a mixed crystal portion formed by diffusion of group III vacancies, and the non-window region 24 includes an active layer 15 having a quantum well structure and does not include a mixed crystal portion. In the window region 23, the absorption of laser light is suppressed by increasing the energy band gap of the window region 23 so that the difference from the energy band gap of the non-window region 24 becomes, for example, 50 meV or more. , COD generation is prevented.

  The substrate 11 includes n-GaAs as a material. The n-buffer layer 12 is a buffer layer necessary for growing a stacked structure of high-quality epitaxial layers on the substrate 11, and includes n-GaAs as a layer material. The n-cladding layer 13 and the n-guide layer 14 have a refractive index and a thickness determined so as to realize an arbitrary optical confinement state with respect to the stacking direction, and include n-AlGaAs as a layer material. The Al composition of the n-guide layer 14 is desirably 20% or more and less than 40%. The Al composition of the n-cladding layer 13 is generally made smaller than the Al composition of the n-guide layer 14 to reduce the refractive index. In the high-power horizontal multimode oscillation element in which the window region is formed in the present invention, the thickness of the n-guide layer 14 is desirably 200 nm or more, for example, about 400 nm. The thickness of the n-cladding layer 13 is preferably about 1 μm or more and about 3 μm. The n-guide layer 14 may be a high-purity layer that is not intentionally doped. However, when the thickness of the n-guide layer 14 is set to 100 nm or more, the influence of residual impurities is large, and doping is not recommended. It is better to apply.

  The active layer 15 includes a lower barrier layer 15a, a quantum well layer 15b, and an upper barrier layer 15c. The lower barrier layer 15a and the upper barrier layer 15c have a barrier function of confining carriers in the quantum well layer 15b, and contain high-purity AlGaAs that is not intentionally doped as a material. The quantum well layer 15b includes, as a material, high-purity InGaAs that is not intentionally doped. The emission recombination energy of the confined carriers is determined by the structure of the potential well determined by the In composition and film thickness of the quantum well layer 15b and the compositions of the lower barrier layer 15a and the upper barrier layer 15c. Although the above has described the configuration of a single quantum well layer (SQW), a multi-stage quantum well layer (MQW) in which a desired number of stacked layers of the quantum well layer 15b, the lower barrier layer 15a, and the upper barrier layer 15c are repeated. It may have the structure of. In the above description, the structure of the high-purity layer not intentionally doped has been described. However, a donor or acceptor may be intentionally added to the quantum well layer 15b, the lower barrier layer 15a, and the upper barrier layer 15c. Further, since the lower barrier layer 15a and the n-guide layer 14 may have the same composition, and the upper barrier layer 15c and the p-guide layer 16 may have the same composition, the lower barrier layer 15a, The upper barrier layer 15c is not necessarily configured.

  The p-guide layer 16 and the p-cladding layer 17 are paired with the n-cladding layer 13 and the n-guide layer 14 described above, and the refractive index and thickness are determined so as to realize an arbitrary optical confinement state in the stacking direction. Is done. The p-guide layer 16 and the p-cladding layer 17 contain p-AlGaAs as a layer material. The Al composition of the p-guide layer 16 is generally 20% or more, and preferably 30% or more. This is because, in the window region 23, the energy shift, which is the amount of change in the energy band gap changed by the mixing process, becomes large, and the mixed crystallizing in the window region 23 is appropriately performed with high selectivity. It is because it is obtained. The Al composition of the p-cladding layer 17 is normally about 40 to 50%. Compared with the n-cladding layer 13 in order to reduce the waveguide loss by shifting the optical field in the layer in the direction of the n-cladding layer 13. -The Al composition of the cladding layer 17 is set slightly larger. The Al composition of the p-guide layer 16 is set smaller than the Al composition of the p-cladding layer 17. In the high-power horizontal multimode oscillation element in which the window region is formed in the present invention, the thickness of the p-guide layer 16 is desirably 200 nm or more, for example, about 400 nm. The thickness of the p-cladding layer 17 is preferably about 1 to 2 μm. The n-guide layer 14 may be a high-purity layer that is not intentionally doped. However, when the thickness of the guide layer is set to 100 nm or more, the influence of the conductivity variation due to residual impurities is large. Therefore, it is better to intentionally perform doping in order to improve manufacturing reproducibility.

Here, the p-cladding layer 17 and the p-guide layer 16 are doped with carbon (C) as an acceptor impurity. The C concentration of the p-guide layer 16 is set to 0.1 to 1.0 × 10 ¹⁷ cm ⁻³ and is preferably about 0.5 to 1.0 × 10 ¹⁷ cm ⁻³ . The p-cladding layer 17 is set to 1.0 × 10 ¹⁷ cm ⁻³ or more.

  The p-contact layer 18 is for ohmic contact between the p-cladding layer 17 and the upper electrode 20. The p-contact layer 18 includes p-GaAs as a layer material. The p-contact layer 18 is doped with a high concentration of C, thereby realizing ohmic contact.

  Next, a method for manufacturing the semiconductor laser element 1 will be described with reference to FIGS. First, as shown in FIG. 3A, an n-buffer layer 12, an n-cladding layer 13, an n-guide layer 14, an active layer 15, a p-guide layer 16, and a p- A clad layer 17 and a p-contact layer 18 are formed. The p-guide layer 16, the p-cladding layer 17, and the p-contact layer 18 are doped with C as an impurity.

  Then, SiN is deposited, for example, to 100 nm on the p-contact layer 18 by using a catalytic CVD (Chemical Vapor Deposition) method. This SiN has a higher N ratio than the stoichiometric composition, and is formed in a state where the flow rates of the raw material silane and ammonia gas are made rich in ammonia. Thereafter, the photolithography process and the etching process are performed to remove SiN other than the region corresponding to the window region 23, thereby forming the accelerating film 25 as shown in FIG. The promotion film 25 is a sparse film because it is SiN formed under N-rich conditions. The accelerating film 25 needs to be formed so as to include the end face from which the laser beam is emitted, and in the plane of the semiconductor laser device 1, a lattice pattern or stripe is formed so as to cover the active layer 15 when viewed from the laser beam emitting side. It forms so that it may become a shape. Then, a suppression film 26 is formed by depositing, for example, 30 nm of SiN formed on the p-contact layer 18 and the promotion film 25 using the catalytic CVD method under Si-rich conditions. This SiN has a higher Si ratio than the stoichiometric composition. Since the suppression film 26 is formed by the catalytic CVD method, it becomes a dense film. Note that the promotion film 25 may be formed after forming the suppression film 26 by forming SiN that forms the suppression film 26 before the promotion film 25 and removing SiN corresponding to the window region 23.

  Next, for example, rapid thermal annealing (RTA) is performed at 915 ° C. for 30 seconds. Since the accelerating film 25 is a sparse film, it can absorb the diffused Ga. For this reason, Ga of each layer located below the promotion film 25 is absorbed by the promotion film 25 by this RTA, and vacancies are generated on the surface of the p-contact layer 18 that contacts the lower part of the accelerating film 25. It diffuses into the active layer 15. And the quantum well layer 15b located under the promotion film | membrane 25 is mixed, and as shown to FIGS. 3-3, the window area | region 23 is formed. As described above, the accelerating film 25 has a function of accelerating the crystallization of the window region 23 by absorbing Ga and promoting the diffusion of vacancies. On the other hand, in the region where the promotion film 25 is not formed, the suppression film 26 is formed so as to be in contact with the p-contact layer 18. Since the suppression film 26 is a dense film, it does not absorb Ga and suppresses the diffusion of Ga. As a result, in the region where the accelerating film 25 is not formed, no vacancies are generated, so that no mixed crystallization is performed and the non-window region 24 does not include a mixed crystal portion. In this way, the suppression film 26 has a function of suppressing mixed crystallization in the non-window region 24.

  Then, after the promotion film 25 and the suppression film 26 are removed, as shown in FIG. 3-4, a photolithography process and an etching process are performed, and the p-contact layer 18 and the p- The upper layer of the clad layer 17 is removed to form a ridge structure. After forming the insulating layer 19, a photolithography process and an etching process are performed to remove the insulating layer 19 other than the region in contact with the upper electrode 20, as shown in FIG. 3-5. Then, after the upper electrode 20 and the lower electrode 21 are formed, the semiconductor wafer is cleaved, the high reflection film 2 and the low reflection film 3 are formed on the cleaved surface, and then the semiconductor laser element 1 is cut to obtain a final result. The semiconductor laser element 1 is obtained.

  As described above, in the semiconductor laser device 1 according to the first embodiment, the p-guide layer 16 that is the layer near the active layer 15, the p-cladding layer 17 that is the upper layer of the p-guide layer 16, and The p-contact layer 18 is doped with C as an impurity.

  Here, in the semiconductor laser device according to the prior art, the p-guide layer, the p-cladding layer, and the p-contact layer are doped with Zn occupying a group III site as an impurity. Zn has a large diffusion constant and is easy to self-diffusion, and easily generates interstitial atoms, and has a large diffusion rate of the generated interstitial atoms. Here, when the promoting function of the promoting film 25 functions appropriately, the group III holes 31a generated by the diffusion of Ga occupying the group III reach the active layer 15 as indicated by the arrow Y0 in FIG. Thus, a window region is formed. However, as indicated by the arrow Y2 in FIG. 4, the generated interstitial Zn30b may recombine with the group III vacancies 31b. Since the interstitial Zn30b and the group III vacancies 31b are all group III, they tend to recombine easily. In particular, Zn is likely to generate interstitial atoms, and the diffusion rate of the generated interstitial atoms is large. Therefore, it is considered that the interstitial Zn and the group III vacancies are recombined in a large amount. In this case, the vacancy concentration decreases and sufficient vacancies do not reach the active layer 15. As a result, the accelerating function of the accelerating film 25 deteriorates, and a large energy band gap cannot be obtained in the window region 23.

  Further, since Zn easily diffuses, as shown by an arrow Y1 in FIG. 4, the generated interstitial Zn30a may reach the active layer 15 by RTA in the IFVD method. In this case, the laser oscillation performance of the quantum well layer 15b in the active layer 15 is hindered. Further, the generation of interstitial Zn 30a causes deterioration of the function of suppressing the crystallization by the suppression film 26, and the energy band gap of the non-window region 24 is increased. Thus, in the prior art, the difference between the energy band gap of the window region and the energy band gap of the non-window region cannot be sufficiently obtained.

  As a result, in the prior art, when the wavelength change of the light absorption amount shifts to the longer wavelength side than the setting in the window region as shown by the curve lsp in FIG. 5 showing the wavelength change of the light absorption amount in the window region. In some cases, light near the wavelength of the oscillated laser beam is absorbed. Further, as shown by the curve ldp in FIG. 5 showing the wavelength change of the light absorption amount in the non-window region, the wavelength change of the light absorption amount is shorter than the set wavelength of the laser light in the non-window region. May shift to

For this reason, as shown in FIG. 5, in the prior art, the wavelength difference Δλ _p of the absorbed light between the window region and the non-window region becomes a small value, and the laser light is absorbed in the window region. Deterioration of the element sometimes occurred. In particular, when the semiconductor laser device is driven under harsh conditions, the second quantum having a wavelength shorter than the wavelength λ ₁ corresponding to the first quantum level, which is the set wavelength of the laser beam. In some cases, laser light having a wavelength λ ₂ corresponding to the level is oscillated. In the prior art, as indicated by the curve lsp, the laser light of this wavelength λ ₂ is absorbed in the window region, and COD is generated. In the window region, not only the wavelength λ ₂ but also a wavelength shorter than the wavelength λ ₁ corresponding to the first quantum level and corresponding to higher-order energy oscillation caused by light holes or the like. Even when laser light was oscillated, light of this wavelength was absorbed. As a result, in the prior art, as shown in the time dependence of the laser beam intensity (Pf) variation in FIG. 6, the laser beam intensity decreases in a short time, and the high reliability is maintained. There is a problem that a semiconductor laser element having a lifetime cannot be obtained.

On the other hand, in the semiconductor laser device 1 according to the first embodiment, the p-guide layer 16, the p-cladding layer 17, and the p-contact layer 18 are doped with C that occupies a group V site as an impurity. Yes. This C has a very small diffusion constant. In other words, C does not self diffuse. For this reason, C does not move to the active layer 15 as illustrated by the arrow Y5 in FIG. 7 even when RTA is performed. For this reason, the laser oscillation function of the quantum well layer 15b and the suppression function of the suppression film 26 are not inhibited. Therefore, in the non-window region, an increase in the energy band gap is appropriately suppressed.

  C is a group IV atom, but enters a group V site and becomes an acceptor in a group III-V compound semiconductor. C occupies a group V site in GaAs, which is a group different from Ga occupying group III absorbed by the promoting film 25. For this reason, C occupying the group V site is difficult to recombine with the group III holes 31 c and 31 d generated by the diffusion of Ga into the promotion film 25. Therefore, in the region corresponding to the window region, the vacancy concentration does not decrease due to recombination, and the generated group III vacancies 31c and 31d smoothly reach the active layer 15 as indicated by arrows Y6 and Y7. The window region is appropriately formed. As a result, since the promoting function of the promoting film 25 is not hindered by C used as an impurity, a large energy band gap can be obtained in the window region 23.

FIG. 8 is a diagram showing a change in the wavelength of light absorption in the window region and the non-window region of the semiconductor laser element 1. In FIG. 8, a curve ldn indicates a change in wavelength of the light absorption amount in the non-window region, and a curve lsn indicates a change in wavelength of the light absorption amount in the window region. In the first embodiment, as a result of using C as an impurity, the promotion function of the promotion film 25 functions appropriately, the mixed crystallization in the window region is sufficiently performed, and the suppression function of the suppression film 26 also appropriately. Function. As a result, the wavelength difference Δλ _n of the absorbed light between the window region and the non-window region can be larger than that in the prior art. In other words, in the semiconductor laser device 1, a sufficient difference between the energy band gap of the window region and the energy band gap of the non-window region can be obtained. Further, as shown by the curve lsn, in the window region, absorption of laser light having a wavelength corresponding to higher-order energy oscillation such as the wavelength λ ₂ corresponding to the second quantum level does not occur. Therefore, even when driven under severe conditions and high-order energy oscillation occurs, the window region does not absorb laser light having a wavelength corresponding to this high-order energy oscillation and generates COD. There is nothing. In addition, since the suppression function of the suppression film 26 also functions properly, the non-window region exhibits absorption characteristics as set as indicated by the curve ldn, and the laser beam having the set wavelength is oscillated with high accuracy. Can do.

  Actually, the energy band gap in the window region and the non-window region of the semiconductor laser element 1 will be described. FIG. 9 is a diagram showing the relationship between the heat treatment temperature of RTA and the amount of energy shift performed for mixed crystallization in the window region and the non-window region of the semiconductor laser element 1. The amount of energy shift is the amount of change in the energy band gap that has changed due to the mixed crystallization process.

  When the crystallization is appropriately promoted, the energy band gap becomes larger after the crystallization in the window region than before the crystallization, so that a large energy shift amount is shown. As described above, in the present first embodiment, the mixing of crystals in the window region can be appropriately promoted by doping C as an impurity. As shown in FIG. 9, in the window region, when RTA is performed at a heat treatment temperature of 900 ° C. or higher, the energy shift amount is 60 meV or higher, and the energy band gap can be increased.

  On the other hand, when mixed crystallization is appropriately suppressed, in the non-window region, a large change in the energy band gap before and after mixed crystallization does not occur, and therefore, a small amount of energy shift is shown. As described above, in the first embodiment, doping with C as an impurity can appropriately suppress mixed crystallization in the non-window region. For this reason, as shown in FIG. 9, in the non-window region, when the RTA heat treatment temperature is 900 ° C., almost no energy shift is observed, and even when the RTA heat treatment temperature is as high as 950 ° C., 20 meV. It only shows the amount of energy shift.

In addition, if the difference between the energy band gap of the window region and the energy band gap of the non-window region is 50 meV or more, absorption of laser light in the window region can be suppressed and generation of COD can be prevented. By the way, even when the light absorption of the end face is suppressed by adopting a window structure, the end face area is an area where local temperature rise is likely to occur, and partial temperature rise due to increase in emission intensity is unavoidable There are many. As the temperature rises, the energy band gap of the semiconductor becomes small at about −0.5 meV / ° C., so that the difference between the energy band gap of the built-in window structure and the energy band gap of the non-window structure is offset. For this reason, if the difference between the energy band gap of the window structure and the energy band gap of the non-window structure can be set to 70 meV, if the temperature difference between the non-window region and the window region is ΔTw, ΔTw
Is acceptable even if it is about 20 ° C. Further, if the difference between the energy band gap of the window structure and the energy band gap of the non-window structure can be set to 100 meV, even if ΔTw is as large as about 50 ° C., it is acceptable. Therefore, it is possible to realize an element with high output so that the difference between the energy band gap of the window structure and the energy band gap of the non-window structure can be set large. Thus, the difference between the energy band gap of the window structure and the energy band gap of the non-window structure needs to be 50 meV or more, more preferably 70 meV, and even more preferably 100 meV. . As shown in FIG. 9, in the semiconductor laser element 1, the difference between the energy band gap of the window region and the energy band gap of the non-window region is set to 50 meV or more by performing RTA at a heat treatment temperature of 900 ° C. or more. be able to. Further, it can be seen that the heat treatment temperatures corresponding to the energy difference of the energy band gap of 70 meV and 100 meV are realized by the heat treatment of about 905 ° C. and 925 ° C., respectively, in the example of FIG.

  Therefore, in the first embodiment, by performing RTA at 900 ° C. or higher, the difference between the energy band gap of the window region of 50 meV or more and the energy band gap of the non-window region can be obtained, and the generation of COD is prevented. Can be prevented.

  As described above, in the first embodiment, the layer formed on the side where the p-type cladding is laminated with respect to the active layer is doped with C as an impurity instead of Zn, thereby promoting the mixed crystallization in the window region. In addition, it is possible to appropriately suppress mixed crystallization in the non-window region. As a result, in the first embodiment, it is possible to realize a highly reliable semiconductor laser element that prevents the generation of COD even when driven under severe conditions.

  Although the semiconductor laser device 1 having a so-called ridge structure has been described as the first embodiment, the present invention is not limited to this, and a semiconductor laser device including a layer having a current confinement function may be used. In this case, as shown in FIG. 10, a current non-injection layer 139 is provided between the p-first contact layer 138a and the p-second contact layer 138b doped with C as an impurity. Then, on the p-first contact layer 138a and the current non-injection layer 139, a p-second contact layer 138b doped with C at a higher concentration than the p-first contact layer 138a and the upper electrode 20 are formed. ing. The p-first contact layer 138a and the p-second contact layer 138b include p-GaAs as a layer material. The current non-injection layer 139 narrows the current injected from the outside through the upper electrode 20 and improves the carrier density in the quantum well layer 15b in the horizontal direction. In order to prevent the current injected from the upper electrode 20 from passing through the inside, the current non-injection layer 139 includes n-GaAs whose conductivity type is n-type in the layer material.

  As shown in FIG. 10, in the case of a semiconductor laser device having a layer having a current confinement function, C, not Zn, is applied to the layer formed on the active layer 15 on the side where the p-type cladding is laminated. Doping as an impurity can appropriately promote mixed crystallization in the window region and suppress mixed crystallization in the non-window region. As a result, as shown in FIG. 11, a large energy shift amount can be obtained in the window region 23, and the energy shift amount can be reduced in the non-window region 24. In this case, as shown in FIG. 11, by performing RTA at 915 ° C. or more, a difference between the energy band gap of the window region 23 and the energy band gap of the non-window region 24 of 50 meV or more is obtained. Similarly, it is possible to realize a highly reliable semiconductor laser element that prevents the generation of COD. The energy difference between the energy band gaps needs to be 50 meV or more, more preferably 70 meV, and even more preferably 100 meV. In the example of FIG. 11, an energy difference of 70 meV is realized near 930 ° C., and an energy difference of 100 meV is realized near 940 ° C. However, in the example of FIG. 11, an energy difference of 100 meV is realized near 940 ° C., but the shift amount of the non-window region reaches 20 meV, and the device performance may be slightly deteriorated.

Here, with reference to FIGS. 12-1 to 12-5, a method of manufacturing the semiconductor laser device shown in FIG. 10 will be described. First, as shown in FIG. 12A, an n-buffer layer 12, an n-cladding layer 13, an n-guide layer 14, an active layer 15, a p-guide layer 16, and a p- An n-GaAs layer for forming the cladding layer 17, the p-first contact layer 138a, and the current non-injection layer 139 is formed. Then, after forming the SiO ₂ film 140, to remove the SiO ₂ layer 140 except the region corresponding to the current non-injection layer 139 performs a photolithography process and an etching process, as shown in FIG. 12-2, SiO ₂ film An etching process is performed using 140 as an etching mask to form a current non-injection layer 139. Note that the etching mask is not necessarily an SiO ₂ film, and the acceleration film 25 formed in the next step may be used as an etching mask. Alternatively, the resist may be formed by etching without forming the SiO ₂ film. Thereafter, as shown in FIG. 12-3, the promotion film 25 and the suppression film 26 are formed in the same way as in the method shown in FIGS. 24. Then, as shown in FIG. 12-4, after the promotion film 25 and the suppression film 26 are removed and the surface of the p-first contact layer 138a and the current non-injection layer 139 is subjected to surface cleaning treatment, As shown in 12-5, p-GaAs is regrown to form the p-second contact layer 138b, and the upper electrode 20 and the lower electrode 21 are formed. A GaAs thin film layer may be provided at the regrowth interface to prevent surface oxidation after etching in the current non-injection layer 139. The formation of the promotion film 25, the formation of the suppression film 26, the RTA treatment, and the removal process of the promotion film 25 and the suppression film 26 shown in FIG. This may be performed after the n-GaAs layer is formed, or after the p-second contact layer 138b is formed. The process described above is before the upper electrode 20 is formed, and it is sufficient if it is a timing at which the active layer 15 can be mixed.

  In FIG. 10, a semiconductor laser device having a horizontal light mode of multimode (hereinafter referred to as “multimode”) is described as a semiconductor laser device having a layer having a current confinement function. As shown, a semiconductor laser device in which the horizontal light mode is a single mode (hereinafter referred to as “single mode”) may be used. In this case, as shown in FIG. 13, a current non-injection layer 139 is provided between the p-first cladding layer 147a doped with C and the p-second cladding layer 147b doped with C. Similarly, in the case of the single mode type semiconductor laser device shown in FIG. 13, the energy band of the window region 23 is obtained by doping C into the layer formed on the active layer 15 on the side where the p-type cladding is laminated. A sufficient difference between the gap and the energy band gap of the non-window region 24 can be obtained, and a highly reliable semiconductor laser device in which the generation of COD is prevented can be realized.

(Embodiment 2)
Next, a second embodiment will be described. In the semiconductor laser device according to the second embodiment, C is doped in the layer near the active layer, and Zn is doped in the layer formed on the upper electrode side of the layer doped with C.

  FIG. 14 is a cross-sectional view of the semiconductor laser according to the second embodiment. As shown in FIG. 14, the semiconductor laser device 201 according to the second embodiment is a semiconductor laser device including a layer having a current confinement function, and is formed on the p-first contact layer 138a and the current non-injection layer 139. A p-second contact layer 238b doped with Zn as an impurity is formed. In the semiconductor laser device 201, the current non-injection layer 139 is formed by using a method similar to the method shown in FIGS. 12-1 and 12-2. Thereafter, the p-first contact layer 138a and the current non-injection layer 139 are subjected to surface cleaning treatment, and then p-GaAs is regrown to form a p-second contact layer 238b doped with Zn. The And the window area | region 23 and the non-window area | region 24 are formed using the method similar to the method shown to FIGS. 12-3 and 12-4. Thereafter, the upper electrode 20 and the lower electrode 21 are formed.

  As described above, in the semiconductor laser device 201 shown in FIG. 14, the p-second contact layer 238b doped with Zn as an impurity is formed instead of the p-second contact layer 138b in the semiconductor laser device shown in FIG. It has a structure.

Incidentally, in the semiconductor laser device shown in FIG. 10, the p-second contact layer 138b doped with C as an impurity is regrown on the p-first contact layer 138a and the current non-injection layer 139. . In this case, C is doped into GaAs by adding halogenated carbon such as CCl ₄ or CBr ₄ or using organic metal-derived carbon as a semiconductor constituent material such as TMGa or TMAs. Here, in order to achieve ohmic contact with the upper electrode, the p-second contact layer 138b needs to be doped with high-concentration C. For example, the carrier concentration of the p-first contact layer 138a is 1 × 10 ¹⁸ cm ⁻³ , whereas the carrier concentration of the p-second contact layer 138b is 1 × 10 ¹⁹ cm ⁻³ . In order to smoothly dope GaAs with such a high concentration of C, it is necessary to perform regrowth in a relatively low temperature range of about 600 ° C. or lower to form the p−second contact layer 138b.

  However, in the case of a semiconductor laser device having a layer having a current confinement function, the process of forming the current non-injection layer 139 is performed, so that the impurity 230 tends to remain at the regrowth interface as shown in FIG. It is easy to get worse. Furthermore, the regrowth in a low temperature region of 600 ° C. or less tends to include point defects 231 caused by antisites and clusters. Due to this point defect 231, the crystal quality of the regrowth interface that is the interface between the p-first contact layer 138 a and the p-second contact layer 138 b may become unstable. For this reason, the absorption of Ga by the accelerating film 25 and the diffusion of vacancies into the active layer 15 are hindered, and the window region 23 may not be formed smoothly. Furthermore, in addition to the point defect 231, there are cases where vacancies are generated at the regrowth interface, and the function of suppressing mixed crystallization in the suppression film 26 does not function properly due to diffusion of the generated vacancies into the active layer 15. There is.

  On the other hand, in the semiconductor laser device 201 according to the second embodiment, the p−second contact layer 238b is formed by doping GaAs with a high concentration of Zn. Here, when Zn is doped, regrowth is performed in a higher temperature range than when C is doped, for example, at a high temperature range of 650 ° C. or higher. In the semiconductor laser element 201, since regrowth is performed in a high temperature region, it is considered that the occurrence of point defects is suppressed. For this reason, in the semiconductor laser element 201, it is considered that the deterioration of the acceleration function of the acceleration film 25 and the deterioration of the suppression function of the suppression film 26 due to point defects are low. Zn has a characteristic that it is more easily diffused than C. However, the semiconductor laser device 201 includes the p-guide layer 16, the p-cladding layer 17, and the p-first contact layer 138 a between the p-second contact layer 238 b doped with Zn and the active layer 15. In particular, the p-cladding layer 17 is formed with a film thickness as thick as 1 μm to 2 μm. Therefore, in the semiconductor laser device 201, there is a distance between the p-second contact layer 238b and the active layer 15 so that Zn does not reach the active layer 15 even when Zn is diffused by RTA. Is provided. Therefore, even when RTA is performed, Zn does not reach the active layer 15, and the laser oscillation performance of the quantum well layer 15b in the non-window region 24 is considered not to be hindered.

  Actually, the energy band gap difference between the window region and the non-window region of the semiconductor laser element 201 will be described. FIG. 16 is a diagram showing the relationship between the RTA heat treatment temperature and the energy shift amount in the window region and the non-window region of the semiconductor laser element 201. As shown in FIG. 16, by performing RTA at 900 ° C., a difference between the energy band gap of the window region 23 and the energy band gap of the non-window region 24 of 50 meV or more can be obtained. Further, even when the heat treatment temperature of the RTA is 900 ° C. or higher, for example, 940 ° C., the energy shift amount in the non-window region 24 is suppressed to a low level, and the window region 23 has a large energy shift. The amount is obtained. In the semiconductor laser device 201, the p-guide layer 16, the p-cladding layer 17, and the p-first contact layer 138a are formed between the active layer 15 and the p-second contact layer 238b. Even if Zn diffuses from the p-second contact layer 238b, it is considered that the diffused Zn does not reach the active layer 15. In other words, in the semiconductor laser device 201, Zn diffused from the p-second contact layer 238b cannot reach the active layer 15 by the distance between the active layer 15 and the p-second contact layer 238b doped with Zn. The distance is set. In particular, since the p-cladding layer 17 has a thickness of 1 μm to 2 μm, it is considered that Zn diffused from the p-second contact layer 238 b cannot reach the active layer 15. The energy difference between the energy band gaps needs to be 50 meV or more, more preferably 70 meV, and even more preferably 100 meV. It can be seen that the heat treatment temperatures corresponding to the energy difference, 50 meV, 70 meV, and 100 meV are realized by heat treatment at about 905 ° C., 912 ° C., and 930 ° C., respectively, in the example of FIG.

  As described above, in the second embodiment, Zn is selected as an impurity by setting the distance between the active layer 15 and the Zn-doped layer to be equal to or greater than the Zn diffusion distance corresponding to the heat treatment temperature of RTA. Even in this case, a highly reliable semiconductor laser element that prevents the generation of COD is realized. In the second embodiment, since the distance between the active layer 15 and the Zn-doped layer is set corresponding to the diffusion distance of Zn at the time of RTA, Zn can be selected as an impurity. The selectivity of the impurity to be doped can be widened.

  As described above, in the semiconductor laser device 1 in which the p-second contact layer 138b is formed by performing regrowth in a low temperature range of about 600 ° C. or less because of C doping, the p-first contact layer 138a and There is a risk that the crystal quality may become unstable at the regrowth interface with the p-second contact layer 138b. However, it seems that destabilization of the crystal quality at the regrowth interface can be prevented by performing the surface cleaning treatment before the regrowth of the p-second contact layer 138b in a high temperature region. For example, the surface cleaning treatment in arsine is performed in a high temperature range of 650 ° C. or higher to prevent impurities from remaining and stabilize the crystal quality of the regrowth interface. As a result, the absorption function of Ga by the accelerating film 25, the diffusion of vacancies into the active layer 15, and the mixed crystal suppression function by the suppression film 26 are appropriately performed, and a more reliable semiconductor laser device can be realized. Conceivable.

  In the second embodiment, the multi-mode type semiconductor laser device 201 has been described. Of course, a single-mode type semiconductor laser device may be used as shown in FIG. The semiconductor laser element shown in FIG. 17 has a p-contact layer 248 doped with Zn as an impurity instead of the p-contact layer 18 in the semiconductor laser element shown in FIG. Also in this case, the distance between the active layer 15 and the Zn-doped p-contact layer 248 is adjusted by adjusting the film thicknesses of the p-guide layer 16, the p-first cladding layer 147a and the p-second cladding layer 147b. May be equal to or longer than the Zn diffusion distance corresponding to the heat treatment temperature of RTA. In particular, it is considered that Zn diffused from the p-contact layer 248 cannot reach the active layer 15 by setting the total film thickness of the p-first cladding layer 147a and the p-second cladding layer 147b to 1 μm to 2 μm. It is done.

  When the distance between the active layer 15 and the Zn-doped layer is set to be equal to or longer than the Zn diffusion distance corresponding to the RTA heat treatment temperature, as shown in FIG. 18, the semiconductor laser device shown in FIG. Instead of the p-first contact layer 138a in 201, a p-first contact layer 238a doped with Zn as an impurity may be formed. In this case, since the thickness of the p-cladding layer 17 is 1 μm to 2 μm, Zn diffused from the p-first contact layer 238 a and the p-second contact layer 238 b cannot reach the active layer 15. it is conceivable that.

  In addition to the multimode type semiconductor laser device, as shown in FIG. 19, a p-second cladding doped with Zn as an impurity instead of the p-second cladding layer 147b in the semiconductor laser device shown in FIG. It may be a single mode type semiconductor laser element in which the layer 247b is formed. In this case, the thicknesses of the p-guide layer 16 and the p-first cladding layer 147a are adjusted, and the distance between the active layer 15 and the p-second cladding layer 247b doped with Zn depends on the heat treatment temperature of the RTA. What is necessary is just to set it as more than the diffusion distance of Zn. For example, it is considered that the diffused Zn cannot reach the active layer 15 by setting the film thickness of the p-first cladding layer 147a to 1 μm to 2 μm.

  Further, as shown in FIG. 20, the present invention is not limited to a semiconductor laser element having a layer having a current confinement function, and may be applied to a semiconductor laser element having a ridge structure. For example, instead of the p-contact layer 18 in the semiconductor laser device 1, a p-contact layer 248 doped with Zn as an impurity is formed. In this case, the thicknesses of the p-guide layer 16 and the p-cladding layer 17 are adjusted so that the distance between the active layer 15 and the p-contact layer 248 and p-cladding layer 257 doped with Zn is equal to the heat treatment temperature of the RTA. What is necessary is just to set more than the diffusion distance of corresponding Zn. For example, it is considered that the diffused Zn cannot reach the active layer 15 by setting the film thickness of the p-cladding layer 17 to 1 μm to 2 μm. Furthermore, as shown in FIG. 20, instead of the p-cladding layer 17 in the semiconductor laser device 1, a p-cladding layer 257 doped with Zn as an impurity is formed. In this case, in addition to the adjustment of the thickness of the p-guide layer 16, the temperature of the RTA heat treatment is reduced, the time of the RTA heat treatment is shortened, and the Zn concentration distribution is adjusted to adjust the p doped with the active layer 15 and Zn. The distance between the contact layer 248 and the p-cladding layer 257 is set to be equal to or longer than the Zn diffusion distance corresponding to the RTA heat treatment temperature. As described above, in the semiconductor laser device according to the second embodiment, the distance between the active layer 15 and the Zn-doped layer is set to be equal to or longer than the Zn diffusion distance corresponding to the RTA heat treatment temperature. By adopting a structure in which the adjacent layer is doped with C, it is considered that the generation of COD can be prevented even when Zn is selected as an impurity.

  Further, although the case where the p-type semiconductor film layer doped with C as an impurity is formed on the active layer has been described, when the n-type semiconductor film layer is formed on the active layer, for example, as shown in FIG. It is preferable to dope Se with impurities. Se is a group VI atom, and enters a group V site and becomes a donor in a group III-V compound semiconductor. In GaAs, Se occupies a group V site that is a group different from Ga occupying group III absorbed by the promoting film 25. Furthermore, since Se has a very small diffusion constant like C, even when RTA is performed, the occurrence of the deterioration of the promoting function of the promoting film and the deterioration of the restraining function of the restraining film is reduced. Conceivable. In the semiconductor laser device shown in FIG. 21, the substrate 311, the p-buffer layer 312, the p-cladding layer 313, the p-guide layer 314, the lower barrier layer 315a, the upper barrier layer 315c, the n-guide layer 316, and the n-cladding. The layer 317 and the n-contact layer 318 are the substrate 11, the n-buffer layer 12, the n-cladding layer 13, the n-guide layer 14, the lower barrier layer 15a, the upper barrier layer 15c, and the p-guide shown in FIG. 16, the p-cladding layer 17 and the p-contact layer 18 are formed of the same layer and a layer material whose n-type or p-type is opposite to each other in the stacking direction. The n-guide layer 316, the n-cladding layer 317, and the n-contact layer 318 are doped with Se.

1 is a perspective view of a semiconductor laser element according to a first embodiment. FIG. 2 is a transverse sectional view of the semiconductor laser element shown in FIG. 1. It is a longitudinal cross-sectional view of the semiconductor laser element shown in FIG. FIG. 6 is a diagram for explaining the method of manufacturing the semiconductor laser element according to the first embodiment. FIG. 6 is a diagram for explaining the method of manufacturing the semiconductor laser element according to the first embodiment. FIG. 6 is a diagram for explaining the method of manufacturing the semiconductor laser element according to the first embodiment. FIG. 6 is a diagram for explaining the method of manufacturing the semiconductor laser element according to the first embodiment. FIG. 6 is a diagram for explaining the method of manufacturing the semiconductor laser element according to the first embodiment. It is a figure explaining the spreading | diffusion of the void | hole and interstitial Zn in the semiconductor laser element concerning a prior art. It is a figure which shows the wavelength change of the light absorption amount in the window area | region and non-window area | region of the semiconductor laser element concerning a prior art. It is a figure which shows the time dependence of the intensity | strength change amount of the laser beam in the semiconductor laser element concerning a prior art. 4 is a diagram for explaining diffusion of vacancies and interstitial Zn in the semiconductor laser element according to the first embodiment; FIG. FIG. 6 is a diagram showing a change in the wavelength of light absorption in the window region and the non-window region of the semiconductor laser element according to the first embodiment. FIG. 3 is a diagram showing a relationship between an RTA heat treatment temperature and an energy shift amount in a window region and a non-window region of the semiconductor laser device according to the first embodiment; FIG. 6 is a diagram showing another example of a cross-sectional view of the semiconductor laser element according to the first embodiment. It is a figure which shows the relationship between the heat processing temperature of RTA and the amount of energy shifts in the window area | region and non-window area | region of the semiconductor laser element shown in FIG. It is a figure explaining the manufacturing method of the semiconductor laser element shown in FIG. It is a figure explaining the manufacturing method of the semiconductor laser element shown in FIG. It is a figure explaining the manufacturing method of the semiconductor laser element shown in FIG. It is a figure explaining the manufacturing method of the semiconductor laser element shown in FIG. It is a figure explaining the manufacturing method of the semiconductor laser element shown in FIG. FIG. 6 is a diagram showing another example of a cross-sectional view of the semiconductor laser element according to the first embodiment. FIG. 6 is a transverse sectional view of a semiconductor laser element according to a second embodiment. It is a figure explaining the state of the regrowth interface in the semiconductor laser element shown in FIG. It is a figure which shows the relationship between the heat processing temperature of RTA, and the amount of energy shifts in the window area | region and non-window area | region of the semiconductor laser element shown in FIG. FIG. 10 is a diagram showing another example of a cross-sectional view of the semiconductor laser element according to the second embodiment. FIG. 10 is a diagram showing another example of a cross-sectional view of the semiconductor laser element according to the second embodiment. FIG. 10 is a diagram showing another example of a cross-sectional view of the semiconductor laser element according to the second embodiment. FIG. 10 is a diagram showing another example of a cross-sectional view of the semiconductor laser element according to the second embodiment. FIG. 10 is a diagram showing another example of a cross-sectional view of the semiconductor laser element according to the first and second embodiments.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,201 Semiconductor laser element 2 High reflection film 3 Low reflection film 4 Laser beam 11 Substrate 12 n-buffer layer 13 n-cladding layer 14 n-guide layer 15 Active layer 15a Lower barrier layer 15b Quantum well layer 15c Upper barrier layer 16 p-guide layer 17 p-cladding layer 18 p-contact layer 19 insulating layer 20 upper electrode 21 lower electrode 23 window region 24 non-window region 25 promotion film 26 suppression film 116 p-guide layer 117 p-cladding layer 118 p-contact Layer 138a p-first contact layer 138b p-second contact layer 139 current non-injection layer 140 SiO ₂ film 147a p-first cladding layer 147b p-second cladding layer 238a p-first contact layer 238b p-second Contact layer 247b p-second cladding layer 248 p-contact layer 257 p-cladding layer

Claims (13)

Equipped with a window region containing a mixed crystal formed by diffusion of group III vacancies and a non-window region having an active layer with a quantum well structure, which absorbs predetermined atoms and promotes diffusion of group III vacancies In the semiconductor laser device for forming the mixed crystal portion by providing an accelerating film on the window region,
A semiconductor laser device, wherein a layer in the vicinity of the active layer is doped with an impurity occupying a group V site.   The semiconductor laser device according to claim 1, wherein the impurity does not self-diffusion.   3. The semiconductor laser device according to claim 1, wherein C is doped in a layer near the active layer.   C is formed on the guide layer formed on the side where the p-type cladding is laminated with respect to the active layer and on at least the active layer side of the clad layer formed on the side where the p-type cladding is laminated with respect to the active layer. The semiconductor laser device according to claim 3, wherein the semiconductor laser device is doped.   5. The semiconductor laser device according to claim 3, wherein C is doped on at least the active layer side of a contact layer formed to inject holes into the active layer.   6. The semiconductor laser device according to claim 1, wherein the semiconductor laser device has a ridge structure. A current non-injection layer provided between the clad layer or the contact layer and confining a current injected from the outside to supply the active layer;
The cladding layer or the contact layer includes a first layer on which a current confinement layer is formed, and a second layer that is regrown after performing a surface cleaning process at 650 ° C. or higher after the formation of the current confinement layer, or And a second layer formed by regrowth in a temperature region of 650 ° C. or higher.   The semiconductor laser device according to claim 1, wherein a difference between an energy band gap in the window region and an energy band gap in the non-window region is 50 meV or more. In a method for manufacturing a semiconductor laser device comprising a window region including a mixed crystal portion formed by diffusion of a group III vacancy and a non-window region having an active layer of a quantum well structure,
An accelerating film forming step of forming an accelerating film on the window region that absorbs predetermined atoms and promotes diffusion of the group III vacancies;
An impurity-containing layer forming step of forming a layer doped with an impurity occupying a group V site in the vicinity of the active layer;
A method for manufacturing a semiconductor laser device, comprising:   10. The method of manufacturing a semiconductor laser device according to claim 9, wherein the impurity-containing layer forming step forms a layer doped with C.   The impurity-containing layer forming step includes at least the active layer of a guide layer provided on a side where a p-type clad is laminated with respect to the active layer and a clad layer provided on a side where a p-type clad is laminated with respect to the active layer. The layer on either the layer side or at least the layer on the active layer side of the contact layer formed for injecting holes into the active layer is formed. The manufacturing method of the semiconductor laser element as described in any one of Claims 1-3. A current non-injection layer forming step of forming a current non-injection layer provided between the clad layer or the contact layer and confining a current injected from the outside to supply the active layer;
The impurity-containing layer forming step includes
A first layer forming step of forming a first layer of the cladding layer provided with a current non-injection layer or a first layer of the contact layer provided with a current non-injection layer;
After the current non-injection layer forming step, a regrowth process after a surface cleaning process of 650 ° C. or higher or a regrowth process in a temperature range of 650 ° C. or higher is performed, and the second layer of the cladding layer or the second layer of the contact layer A second layer forming step of forming
The method for manufacturing a semiconductor laser device according to claim 9, comprising: 13. The semiconductor laser device according to claim 9, further comprising a heat treatment step of diffusing the group III vacancies at a heat treatment temperature of 900 ° C. or more to crystallize the window region. Manufacturing method.

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