JP2009170658A - Production process of semiconductor laser device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the output characteristics of a semiconductor laser and to avoid deterioration of the outgoing end face by restraining diffusion of impurities in a step of forming an embedded regrowth type end face window structure. <P>SOLUTION: The process comprises a step of carrying out crystal growth of a laminated structure including a first clad layer 12, a first light guide layer 13, an active layer 14, a second light guide layer 15, and a second clad layer 16 on a substrate 11, a step of forming an opening part by removing a part of the laminated structure by etching, a step of forming an embedding growth part 19b by carrying out embedding growth of crystals made from a material with a forbidden band width larger than that of the active layer in the opening part, a step of forming an optical waveguide, and a step of forming an outgoing end face by forming cleavage so that the cleavage plane passes along the embedding growth part. In the step of forming the embedding growth part, crystal growth is carried out on the condition that it progresses from the sidewall surface of the opening part and hardly progresses from the surface of the regions other than the opening part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a semiconductor laser device having a buried regrowth type window structure on a cavity end face, and more particularly to improvement of device characteristic deterioration caused by a buried regrowth process.

  The window structure (hereinafter referred to as “end window structure” or “window structure”) of the cavity end face in the edge emitting semiconductor laser is the light to be output or resonated by devising the light emitting end face of the semiconductor laser. Refers to a structure that prevents absorption near the end face. By applying this end face window structure, it is possible to improve the light output level at which optical destruction (COD) of the light exit end face of the resonator occurs, and as a result, improve the reliability of the element at a high temperature or high output state. And output performance can be improved.

  As an element structure in which such an end face window structure is devised, for example, the element structure disclosed in Patent Document 1 or Patent Document 2 is widely known.

  Patent Document 1 discloses a technique for expanding the band gap energy in the vicinity of an end face by adding an impurity such as zinc (Zn). An ion implantation method for adding an impurity is a method in which a part of an active layer is disordered by performing heat treatment after ion implantation of an impurity element. In the diffusion method, a disordered material that disorderes the active layer by mixing with the active layer is formed on the upper part of the portion that becomes the end face window portion, and then the disordered material is diffused by heat treatment to partially remove the active layer. It is a method of disordering.

  Patent Document 2 proposes a buried regrowth type end window structure that forms an end window structure using regrowth. A nitride semiconductor laser device using an aluminum indium gallium nitride (AlInGaN) -based material that has been attracting attention in recent years has been disclosed as shown in FIG.

This figure shows a cross section of the semiconductor laser device in the cavity direction. For example, a buffer layer 102, an n-type nitride semiconductor layer 103, an active layer 104, and a p-type nitride semiconductor layer 105 are sequentially stacked on the substrate 101 to form a semiconductor laser structure. Next, the outermost surface of the p-type nitride semiconductor layer 105 is covered with a protective film 106 such as SiO ₂ . Thereafter, a part of the protective film 106 is opened using photolithography. Next, the trench 107 is formed by etching from the p-type nitride semiconductor layer 105 to the n-type nitride semiconductor layer 103 through the opening of the protective film 106. The position of the groove 107 corresponds to one end of the resonator. Thereafter, the end face window structure 108 is formed by embedding the groove 107 by embedding regrowth using the protective film 106 as a mask. Further, the end face of the resonator having the end face window structure is formed by cleaving in a plane perpendicular to the paper surface at the position of the end face window structure 108.
JP 2001-210907 A JP 2003-60298 A T.A. Takazawa, J .; Shimizu, T .; Journal of ELECTRONIC MATERIALS, Volume 36, Issue 4, pp. Ueda; 403-408, 2007

  However, as a result of experiments conducted by the inventors, it was difficult to improve the output characteristics of the semiconductor laser and to suppress the degradation of the emission end face even in the case of the conventional method for forming the buried regrowth end face window structure. there were.

That is, Si is formed from a protective film 106 such as SiO ₂ formed so as not to be deposited on the p-type nitride semiconductor layer 105 in a region other than the region embedded as the end surface window at the time of embedding regrowth for forming the end surface window. This is because the crystals that are diffused as impurities and formed as end face window films become n-type semiconductors. As a result, it has been found that light absorption occurs due to the impurity level, and the function as the end face window structure cannot be obtained sufficiently, or a leak current flows through the end face window portion, which adversely affects the device.

  An object of the present invention is to solve the above-mentioned conventional problems, suppress impurity diffusion in the step of forming a buried regrowth type end face window structure, improve the output characteristics of the semiconductor laser, and deteriorate the emission end face. An object of the present invention is to provide a method of manufacturing a semiconductor laser device that can avoid the above-described problem.

  In order to solve the above problems, a method of manufacturing a semiconductor laser device of the present invention is a method of manufacturing a semiconductor laser device having a striped optical waveguide and an emission end face formed by at least one end of the optical waveguide. A step of crystal-growing a laminated structure including a first cladding layer, a first light guide layer, an active layer, a second light guide layer, and a second cladding layer on a substrate, and etching a part of the laminated structure Removing and forming an opening; embedding and growing a crystal made of a material having a larger forbidden band width than the active layer in the opening; and forming the optical waveguide; And cleaving the cleaved growth portion so that the cleaved surface passes, thereby forming the emission end face. In the step of forming the buried growth portion, the growth of the crystal is performed under the condition that it proceeds from the side wall surface of the opening and does not proceed from the surface of the region excluding the opening.

  According to the method for manufacturing a semiconductor laser device of the present invention, in the growth in which a material having a forbidden band width larger than that of the active layer is embedded, the growth direction proceeds from the side wall of the groove, and substantially from the bottom of the groove and the surface of the region other than the groove. Thus, the protective film that has been necessary in the past is not required. As a result, the window function deterioration due to the diffusion of impurities from the protective film and the leakage current problem through the end face window portion can be solved, and the output characteristics can be improved and a semiconductor laser device with excellent element life can be manufactured. It becomes possible.

  The manufacturing method of the semiconductor laser device of the present invention can take the following aspects based on the above configuration.

  That is, the side wall surface of the opening is a {10-10} plane, a {10-11} plane, a {10-12} plane, a {11-20} plane, a {11-21} plane, or The {11-22} plane can be used.

  Further, in the step of forming the buried growth portion, in the step of forming the optical waveguide, a high-density defect region is formed by a coupling portion of the front end surface of the crystal that grows starting from each of the side wall surfaces of the opening. The optical waveguide is formed to be shifted from the symmetry center of the buried growth portion in the resonator direction, and the cleavage in the step of forming the emission end face is performed at a position where the cleavage plane does not include the high-density defect region. Is preferred.

  Further, in the step of forming the buried growth portion, in the step of forming the optical waveguide, a high-density defect region is formed by a coupling portion of the front end surface of the crystal that grows starting from each of the side wall surfaces of the opening. The optical waveguide is preferably formed so that at least one end portion is located in a region not including the high-density defect region.

  When an optical waveguide is formed in a high-density defect region, light absorption occurs and leads to heat generation at the resonator end face. Thereby, the lifetime of the laser element is shortened. In other words, by setting the optical waveguide formation position to a region that does not include the high-density defect region existing in the joint portion of the end face window film, it is possible to suppress the heat generation of the end face window portion and avoid laser element degradation. Become.

  In the step of forming the buried growth portion, it is preferable that the crystal is grown using an organic nitrogen raw material.

In the step of forming the buried growth portion, the material represented by the general formula: Al _X In _Y Ga _(1-XY) N (0 ≦ X ≦ 1, 0 ≦ Y ≦ 1, X + Y = 1) It is preferable to form the buried growth portion made of the crystal.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
A method for manufacturing a semiconductor laser device according to the first embodiment of the present invention will be described with reference to the drawings. 2, 3 </ b> Aa to 3 </ b> Ga, and FIGS. 2 is a cross-sectional view, and FIGS. 3Aa to 3Ga are top views. 3Ab to 3Gb are cross-sectional views taken along line II (resonator direction) in FIGS. 3Aa to 3Ga, respectively.

  3Dc to 3Gc show cross sections along the II-II line (direction perpendicular to the resonator direction) in FIGS. 3Aa to 3Ga. 3Dd and 3Ed show cross sections along the line III-III (direction perpendicular to the resonator direction) in FIGS. 3Da and 3Ea.

  Note that, in the drawings, for convenience of illustration, only the structure of one unit semiconductor laser device is extracted and shown. In practice, a plurality of semiconductor laser devices are formed so as to repeat the same structure as a whole, and are separated into one semiconductor laser device at a predetermined stage of the manufacturing process.

First, as shown in FIG. 2, an n-type Al _0.05 layer having a thickness of 2 μm is formed on a substrate 11 made of n-GaN, for example, by metal organic chemical vapor deposition (MOCVD). A first cladding layer 12 made of GaN _0.95 N is grown. Next, the first light guide layer 13 made of n-type GaN having a thickness of 0.1 μm is grown.

Next, a quantum well structure in which an In _0.02 Ga _0.98 N barrier layer having a thickness of 7.5 nm and an In _0.10 Ga _0.9 N quantum well structure having a thickness of 3 nm are alternately grown for three periods. The active layer 14 and the second light guide layer 15 made of p-type GaN having a thickness of 0.1 μm are grown. Next, from a strained superlattice having a thickness of 0.48 μm, in which a p-type Al _0.1 Ga _0.9 N layer having a thickness of 1.5 nm and a p-type GaN layer having a thickness of 1.5 nm are alternately stacked for 160 periods. A second cladding layer 16 is grown. Finally, a contact layer 17 made of p-type GaN having a thickness of 0.05 μm is grown.

  As a method used for crystal growth, an MOCVD method, a molecular beam growth (MBE) method, a chemical beam growth (CBE) method, or the like can be used. The raw materials for the MOCVD method include, for example, trimethyl gallium as the Ga raw material, trimethyl indium as the In raw material, trimethyl aluminum as the Al raw material, ammonia as the N raw material, silane gas as the Si raw material for n-type impurities, and p-type. Biscyclopentadienylmagnesium can be used as the impurity Mg raw material.

Next, as shown in FIGS. 3Aa and 3Ab, an SiO ₂ protective film 18 having a thickness of 400 nm is formed on the contact layer 17 made of p-type GaN by, for example, plasma CVD using silane gas as a raw material. . Next, using photolithography, a part of the SiO ₂ protective film 18, that is, the region serving as the resonator end face is removed with hydrofluoric acid to form a rectangular opening 18a. The shape of the opening 18a is not limited to the quadrangular shape as in the present embodiment, and may be, for example, a circular shape or a polygonal shape.

Subsequently, using the SiO ₂ protective film 18 having the opening 18a as a mask, for example, inductively coupled plasma (ICP) dry etching using Cl ₂ gas is performed. Thereafter, the SiO ₂ protective film 18 is removed using hydrofluoric acid.

  By this dry etching, as shown in FIGS. 3Ba and 3Bb, the p-type contact layer 17, the second cladding layer 16, the second light guide layer 15, the active layer 14, the first light guide layer 13, and the first cladding layer. 12 is selectively removed, and an opening 19a exposing the substrate 11 is formed. The first cladding layer 12 may be left tens of nanometers and the substrate 11 may not be exposed. Alternatively, the first light guide layer 13 may be left several tens of nm so that the first cladding layer 12 is not exposed.

Next, as shown in FIGS. 3Ca and 3Cb, a single crystal made of a material having a larger forbidden band width than that of the active layer 14 is embedded and grown in the opening 19a formed by etching, for example, using the MOCVD method. An end face window film 19b made of a buried growth portion is formed. This buried growth is performed under the condition that the growth does not proceed in the {0001} plane direction and proceeds only from the side wall surface of the opening 19a and does not proceed from the surface of the region excluding the opening 18a. However, the case where the embedded growth does not proceed includes not only the case where it does not proceed at all, but also the case where there is substantially no progress of crystal growth that affects the characteristics of the device. According to this step, since the end face window film 19b can be formed without the SiO ₂ protective film for forming the mask, it is possible to prevent impurities from diffusing from the SiO ₂ protective film to the end face window film 19b.

In this step, in the growth using ammonia gas, which is a nitrogen source material generally used in the MOCVD method, crystals grow simultaneously in the {0001} plane direction as well as from the side wall surface of the opening 19a. However, for example, as shown in Non-Patent Document 1, if dimethylhydrazine ((CH ₃ ) ₂ N—NH ₂ ) is used as a nitrogen source material, a crystal can be grown only from the side wall surface of the opening 19a. Is possible. That is, since the surface of the region excluding the opening 18a, in other words, the surface of the p-type contact layer 17 around the opening 18a is a surface orthogonal to the side wall surface of the opening 19a, the crystal growth does not proceed. Absent. Similarly, substantially no crystal growth proceeds from the bottom of the opening 19a.

  In addition, when the peripheral part of the bottom part of the opening part 19a is not completely flat, for example, when a curved surface is formed at the peripheral edge and there is a surface having an angle with respect to the flat bottom surface, crystal growth is caused from the part. There is a possibility of progressing slightly. However, it can be considered that the growth that affects the characteristics of the end face window film 19b does not proceed and the crystal growth does not proceed substantially.

  In this manner, the end face window film 19b can be formed by crystal growth only from the side wall surface of the opening 19a, for example, the {10-10} plane and the {11-20} plane. In the burying growth using dimethylhydrazine as the nitrogen source material, the side wall surface of the opening 19a is {10-11} plane, {10-12} plane, {11-21} plane, or {11 Even an inclined surface of −22} plane can be embedded while maintaining the depth and plane orientation of the opening 19a.

  Further, when the end face window film 19b is formed, it is not necessary to completely embed the region if only the region contributing to the optical waveguide can be embedded.

  On the other hand, after the end face window film 19b is formed, a space 19c may remain at the interface between the surface of the laminated structure exposed at the bottom of the opening 19a and the end face window film 19b in the previous etching step. However, the space 19c does not adversely affect the device characteristics. Further, depending on the growth conditions, the space 19c may appear to disappear, but even in that case, the bottom of the end face window film 19b is chemically bonded to the surface of the substrate 11 on the upper side in the stacking direction. Absent.

Nitrogen source materials used for burying regrowth for forming the end face window film 19b include monomethyl hydrazine ((CH ₃ ) H—NH ₂ ) and tertiary butyl hydrazine (C (CH ₃ ) _{3, which} are the same organic nitrogen raw materials as dimethylhydrazine. HN—NH ₂ ), tertiary butylamine (C (CH ₃ ) ₃ NH ₂ ), ethyl azide (C ₂ H ₅ N ₃ ), or the like may be used.

  Further, dimethylhydrazine is known to exhibit high decomposition efficiency with respect to ammonia at 800 ° C. or lower. Therefore, regarding the formation temperature of the end face window film 19b, for example, when forming single crystal GaN, a film formation temperature of 900 ° C. or higher is necessary when ammonia is used, whereas by using dimethylhydrazine, 600 ° C. to Single crystal GaN can be deposited at 800 ° C. In other words, the end face window film 19b can be embedded at a temperature equal to or lower than the growth temperature of the active layer 14, and indium in the InGaN forming the active layer 14 can be suppressed.

By using the method as described above, it is possible to form the end face window film 19b having a forbidden band width larger than that of the active layer only from the side wall surface of the opening 19a without growing in the {0001} plane direction. . Therefore, it is not necessary to provide a protective film such as SiO _{2 in} a region other than the opening 19a. Since the protective film is not required, it is possible to solve the problem of light absorption accompanying the impurity diffusion from the protective film that occurs during the buried growth.

Note that the material of the end face window film 19b is Al _X In _Y Ga _(1-X—Y) N (0 ≦ X ≦ 1, 0 ≦ Y ≦ 1, X + Y = 1), which is more forbidden than the active layer. What is necessary is just to choose the value of X and Y so that a width | variety may become large.

In the next manufacturing process, an SiO ₂ film (not shown) having a thickness of 300 nm is formed on the contact layer 17 and the end face window film 19b by using a plasma CVD method. Thereafter, the SiO ₂ film is selectively removed by photolithography and etching using hydrofluoric acid to form a stripe-shaped SiO ₂ mask (not shown) having a width of 1.5 μm. Thereafter, ICP dry etching using Cl ₂ gas is performed to etch a region not covered with the striped SiO ₂ mask to a depth of 0.35 μm. As a result, as shown in FIGS. 3Da, 3Db, 3Dc, and 3Dd, a ridge stripe portion 20 having a width of 1.5 μm is formed. Thereafter, the SiO ₂ mask is removed with hydrofluoric acid. 3Dc shows a cross section of the end face window film 19b along the line II-II in FIGS. 3Da and 3Db. On the other hand, FIG. 3Dd shows a cross section of the resonator section along the line III-III in FIGS. 3Da and 3Db.

Next, by a plasma CVD method so as to cover the upper surface of the substrate 11, to form a SiO ₂ film having a thickness of 300 nm (not shown), using photolithography, exposing the SiO ₂ film on the contact layer 17 Then, the SiO ₂ film is selectively removed by dry etching or the like, and an insulating film 21 is formed as shown in FIGS. 3Ea, 3Eb, 3Ec, and 3Ed.

  3Ec shows a cross section of the end face window film 19b along the line II-II in FIGS. 3Ea and 3Eb. On the other hand, FIG. 3Ed shows a cross section of the resonator section along line III-III in FIGS. 3Ea and 3Eb.

  Thereafter, a p-side electrode 22 made of palladium (Pd) having a thickness of 35 nm and platinum (Pt) having a thickness of 40 nm is formed on the contact layer 17 using an EB vapor deposition method or the like. Subsequently, a wiring electrode 23 made of titanium (Ti) with a thickness of 50 nm, Pt with a thickness of 200 nm, and Ti with a thickness of 50 nm is formed by using photolithography and EB vapor deposition. . The wiring electrode 23 has a width in the direction parallel to the cleavage plane of 20 μm.

  Next, as shown in FIGS. 3Fa, 3Fb, and 3Fc, a film in which Ti having a thickness of 50 nm and Au having a thickness of 1000 nm are stacked is formed into a planar shape having a thickness of 550 μm in the resonator direction and 150 μm in the cleavage direction. , Photolithography, and EB deposition apparatus. Further, the thickness of Au is increased to 10 μm by electrolytic plating, and the pad electrode 24 is formed.

  Thereafter, the thickness of the substrate 11 is thinned to about 100 μm using a diamond slurry, and then, as shown in FIGS. 3Gb and 3Gc, Ti having a thickness of 5 nm as an n-side electrode 25 is formed on the back surface of the substrate 11. Is formed by using an EB vapor deposition apparatus with Pt having a thickness of 10 nm and Au having a thickness of 1000 nm.

  Next, in order to form a resonator end face, as shown in FIG. 3Ga, cleavage is performed at the AA plane and the BB plane for each resonator length, and separated into individual resonators as shown in FIG. 3Gb. . FIG. 3Gc shows a cross section of the end face window film 19b along the line II-II in FIG. 3Ga. On the other hand, FIG. 3Gd shows a cross section of the resonator section along line III-III in FIG. 3Ga.

  As described above, a semiconductor laser device including a material having a larger forbidden band width than that of the active layer on the end face of the resonator can be manufactured without the need for a protective film in the burying growth process. As a result, it is possible to avoid the diffusion of impurities from the protective film, improve the output characteristics of the semiconductor laser, and improve the device life.

  According to the manufacturing method of the present embodiment, an effect that the crystallinity of the end face window film 19b is good is also obtained. This will be described with reference to FIGS.

  FIG. 4A is a perspective view showing a process of forming the end face window film 19b by buried growth. The laminated film 30 is a simplified illustration of a plurality of films that form a resonator structure formed on the substrate 11. In this step, in the conventional crystal growth using ammonia as a group V source, the growth proceeds by taking over the defects extending in the (0001) direction from the substrate. This is because crystals grow from the bottom surface of the opening 19a.

  In contrast, in the present embodiment using, for example, dimethylhydrazine, which is an organic nitrogen raw material, crystals grow only from the side wall surface of the opening 19a, so that defects extending in the (0001) direction from the substrate are inherited. There is no. When the defects in the region serving as the end face window are reduced, light absorption due to the defects can be suppressed, and a semiconductor laser device with improved output characteristics and excellent life characteristics can be obtained. Although an example in which GaN is used as the substrate of the semiconductor laser device has been shown, when using a substrate such as sapphire, SiC, or Si, there are more substrate defects than when using a GaN substrate. The effect of reducing defects in the window region becomes significant.

  After a good end window film 19b is formed as shown in FIG. 4A, a ridge stripe is formed as shown in FIG. 4B. Although illustration is omitted, after further necessary elements are formed, as shown in FIG. 4C, the semiconductor laser device is separated into pieces by a cleavage process. At this time, since the end face window film 19b has a good crystallinity growing in the horizontal direction from the side wall surface of the opening 19a, a good cleavage surface is obtained, and a cleavage failure is unlikely to occur.

  In the structure of the above embodiment, the end face window film 19b does not have a structure for confining light. Therefore, since the optical waveguide shape by the end face reflection is different from the optical waveguide shape with optical confinement, the light coupling efficiency is lowered, which may adversely affect the threshold value and the laser characteristics. Therefore, the length of the end face window film 19b in the resonator direction is preferably 1 μm to 50 μm, and more preferably 1 μm to 10 μm.

  Further, the length of the end face window portion in the resonator direction after cleavage is half of the length of the end face window film 19b in the resonator direction. Therefore, the length of the end face window film 19b in the resonator direction may be 2 μm to 100 μm.

(Second Embodiment)
A manufacturing method of the semiconductor laser device according to the second embodiment will be described with reference to FIGS. 5A and 5B. FIG. 5A is a top view showing a ridge stripe forming step of the method of manufacturing the semiconductor laser device according to this embodiment. FIG. 5B is a cross-sectional view of the semiconductor laser device after completion, taken along line IV-IV in FIG. 5A.

  The manufacturing method of this embodiment differs from the manufacturing method of the first embodiment only in the ridge stripe forming method, and the other steps are the same. The same elements as those in the first embodiment are denoted by the same reference numerals, and the description will not be repeated.

  In the buried growth for forming the end face window film 19b, as shown in FIG. 5A, a coupling portion 26 (broken area in the figure) is formed at a position that bisects the end face window film 19b. It is an area. That is, when the end face window film 19b is formed by regrowth, crystals are formed from the {10-10} plane and the {11-20} plane, but the growth rate differs for each plane that is the starting point of growth. Therefore, as shown in FIG. 5A, the coupling portions 26 on each surface are formed, and high-density defects are generated.

  In the present embodiment, the ridge stripe portion 20 is shifted from the coupling portion 26 (high density defect region) at a position where the end face window film 19b is divided into two, and the low density defect region 27 (other than the broken line in the figure) of the end face window film 19b. Region). Thereafter, in the same manner as in the first embodiment, after forming an insulating film, an electrode, etc., cleavage is performed on the CC plane and the DD plane, and the semiconductor laser having the end face window structure as shown in FIG. Get the device. As a result, a high-density defect region is not included in the cleavage plane, and it is possible to obtain a semiconductor laser that is more excellent in output characteristics and life characteristics than in the first embodiment.

(Third embodiment)
A method for manufacturing a semiconductor laser device according to the third embodiment will be described with reference to FIGS. 6A and 6B. The manufacturing method of this embodiment is the same as the manufacturing method of the first and second embodiments, except that the ridge stripe forming method is different.

  As shown in FIG. 6A, since the burying growth occurs from each of the side wall surfaces of the opening 19a, the high-density defect region is not limited to the bonding portion 26 at the position where the end face window film 19b is divided into two, but also bonding portions of other portions. 28 also exists.

  In the present embodiment, as in the second embodiment, the ridge stripe portion 20 is formed at a position as shown in FIG. 6A so that the optical waveguide region does not cover the high-density defect region, and is the same as in the first embodiment. Then, the ridge stripe portion 20 is formed only in the low density defect region 27 as shown in FIG. 6B by forming an insulating film, electrodes, etc., and cleaving on the EE plane and the FF plane. Is possible. As a result, the output characteristics of the semiconductor laser and the device life can be improved further than in the second embodiment.

  In the first to third embodiments, an example in which GaN is used as the substrate of the semiconductor laser device has been described. However, the present invention is also applied to the case where other substrates such as sapphire, SiC, and Si are used. Can do.

  In the above embodiment, the manufacturing method of the present invention has been shown by way of example in the case of manufacturing a semiconductor laser device having a ridge waveguide type optical waveguide. However, the present invention is also applied to a method of manufacturing a buried laser device. Applicable.

  The method for manufacturing a semiconductor laser device of the present invention can avoid characteristic deterioration due to impurity diffusion during buried regrowth, and is useful for manufacturing a nitride-based semiconductor laser device used for a high-density optical disk device.

Sectional drawing which shows the semiconductor laser apparatus which has an end face window structure of the buried regrowth type of a prior art example Sectional drawing which shows the process of the manufacturing method of the semiconductor laser apparatus concerning the 1st Embodiment of this invention A top view showing a process of a manufacturing method of the semiconductor laser device according to the same embodiment II sectional view in FIG. 3Aa A top view showing a process of a manufacturing method of the semiconductor laser device according to the same embodiment II sectional view in FIG. 3Ba A top view showing a process of a manufacturing method of the semiconductor laser device according to the same embodiment II sectional view in FIG. 3Ca A top view showing a process of a manufacturing method of the semiconductor laser device according to the same embodiment II sectional view in FIG. 3Da II-II sectional view in FIG. 3Da III-III sectional view in FIG. 3Da A top view showing a process of a manufacturing method of the semiconductor laser device according to the same embodiment II sectional view in FIG. 3Ea II-II sectional view in FIG. 3Ea III-III sectional view in FIG. 3Ea A top view showing a process of a manufacturing method of the semiconductor laser device according to the same embodiment II sectional view in FIG. II-II sectional view in FIG. A top view showing a process of a manufacturing method of the semiconductor laser device according to the same embodiment Sectional drawing corresponding to the cross section along the II line in FIG. 3Ga II-II sectional view in FIG. 3Gb III-III sectional view in FIG. 3Gb The perspective view which shows the process of forming an end surface window film | membrane by the embedding growth in the manufacturing method of the semiconductor laser apparatus concerning embodiment of this invention. The perspective view which shows the ridge stripe formation process Perspective view of the main part showing the cleavage process The top view which shows the ridge stripe formation process in the manufacturing method of the semiconductor laser apparatus concerning the 2nd Embodiment of this invention Sectional drawing of the semiconductor laser apparatus after completion along line IV-IV in FIG. 5A The top view which shows the ridge stripe formation process in the manufacturing method of the semiconductor laser manufacture concerning the 3rd Embodiment of this invention Sectional drawing of the semiconductor laser apparatus after completion along the VV line in FIG. 6A

Explanation of symbols

11 substrate 12 first cladding layer 13 first optical guiding layer 14 active layer 15 and the second optical guide layer 16 and the second clad layer 17 contact layer 18 SiO ₂ protective film 18a opening 19a groove opening 19b Tanmenmadomaku 19c space 20 Ridge Stripe portion 21 Insulating film 22 P-type electrode 23 Wiring electrode 24 Pad electrode 25 N-type electrode 26 Coupling portion (high-density defect region)
27 Low-density defect region 28 Bonding portion (high-density defect region)
30 laminated film 101 substrate 102 buffer layer 103 n-type nitride semiconductor layer 104 active layer 105 p-type nitride semiconductor layer 106 protective film 107 cutting groove 108 end face window

Claims (6)

A manufacturing method of a semiconductor laser device having a stripe-shaped optical waveguide and an emission end face formed by at least one end of the optical waveguide,
Crystal growth of a laminated structure including a first cladding layer, a first light guide layer, an active layer, a second light guide layer, and a second cladding layer on a substrate;
Removing a part of the laminated structure by etching to form an opening;
A step of embedding and growing a crystal made of a material having a larger forbidden band width than the active layer in the opening to form a buried growth portion;
Forming the optical waveguide;
Forming the emission end face by cleaving so that a cleaved surface passes through the buried growth portion, and
In the step of forming the buried growth portion, the growth of the crystal is performed under a condition that proceeds from the side wall surface of the opening and does not proceed from the surface of the region excluding the opening. Production method.   The side wall surface of the opening is a {10-10} plane, a {10-11} plane, a {10-12} plane, a {11-20} plane, a {11-21} plane, or a {11 2. The method of manufacturing a semiconductor laser device according to claim 1, wherein the semiconductor laser device is a -22} plane. In the step of forming the buried growth portion, a high-density defect region is formed by a joint portion of the front end face of the crystal that grows starting from each of the side wall surfaces of the opening,
In the step of forming the optical waveguide, the optical waveguide is formed by being shifted from the symmetry center in the resonator direction of the buried growth portion,
The method of manufacturing a semiconductor laser device according to claim 1, wherein the cleavage in the step of forming the emission end face is performed at a position where the cleavage face does not include the high-density defect region. In the step of forming the buried growth portion, a high-density defect region is formed by a joint portion of the front end face of the crystal that grows starting from each of the side wall surfaces of the opening,
The method of manufacturing a semiconductor laser device according to claim 1, wherein in the step of forming the optical waveguide, the optical waveguide is formed so that at least one end portion is located in a region not including the high-density defect region.   The method of manufacturing a semiconductor laser device according to claim 1, wherein in the step of forming the buried growth portion, the crystal is grown using an organic nitrogen raw material. In the step of forming the burying growth part, materials of the general formula expressed by _{Al X In Y Ga (1-} X-Y) N (0 ≦ X ≦ 1,0 ≦ Y ≦ 1, X + Y = 1) crystal The method of manufacturing a semiconductor laser device according to claim 1, wherein the buried growth portion is formed.

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