JP6520527B2 - Semiconductor laser device manufacturing method - Google Patents

Description

  The present invention relates to a method of manufacturing a semiconductor laser device.

  As a method of manufacturing a semiconductor laser device, there is a method of forming a groove for assisting cleavage in a semiconductor layer and cleaving the wafer along the groove (for example, Patent Documents 1 and 2). Further, there is a structure in which grooves are provided on both sides of an optical waveguide region of a semiconductor laser device in order to suppress the occurrence of ripples in a far field pattern (FFP) of the semiconductor laser device (for example, Patent Document 3) ). Such a groove reflects or scatters the stray light in the semiconductor laser device, thereby reducing the ripple of the FFP in the horizontal direction (the surface direction of the semiconductor layer).

Unexamined-Japanese-Patent No. 2009-200478 JP 2011-211244 A JP, 2010-003806, A

  However, there is still room for improvement to further improve the yield. For example, when cleavage is performed using a groove that assists cleavage, although it is likely to be broken along the line connecting the ends of the groove, since the groove has a width, the line connecting the ends of the grooves coincides with the cleavage plane It is not always the case. Therefore, there is a possibility that a crack may occur in a direction other than the cleavage plane, or cutting may occur in a direction deviated from the cleavage plane. Further, since the ripple reduction groove is provided near the cleavage position, it has an adverse effect on cleavage, and depending on the position to be formed, it becomes difficult to obtain a stable cleavage facet.

The present disclosure includes the following inventions.
Preparing a wafer having a semiconductor laminate having an active layer formed on a substrate;
In the semiconductor laminate, a ridge extending in the X direction, a plurality of first recesses spaced apart from the ridge and extending in the Y direction intersecting the X direction, and the ridge closer to the ridge than the first recess Forming a plurality of second recesses to be arranged;
Cleaving the wafer to form a light emitting surface by cleaving the wafer along the plurality of first recesses;
A method of manufacturing a semiconductor laser device comprising
The second recess is formed in the vicinity of the light exit surface,
The length in the Y direction of the second recess is L, and the length in the Y direction of a portion of the second recess where the Y coordinate, which is the coordinate in the Y direction, matches the first recess is L _a (0 <when the _{L a),} a method of manufacturing a semiconductor laser element to satisfy the relation of _{L a <(L-L a} ).

  According to the above manufacturing method, a good cleavage plane can be obtained, and the ripple of FFP of the obtained semiconductor laser device can be reduced.

FIG. 1A is a schematic plan view illustrating a method of manufacturing a semiconductor laser device according to an embodiment of the present invention. FIG. 1B is a cross-sectional view taken along a line AA of FIG. 1A. FIG. 2A is a schematic plan view illustrating a method of manufacturing a semiconductor laser device according to an embodiment of the present invention. FIG. 2B is a cross-sectional view taken along line B-B of FIG. 2A. FIG. 2C is a cross-sectional view taken along the line C-C of FIG. 2A. FIG. 3A is a schematic plan view illustrating a method of manufacturing a semiconductor laser device according to an embodiment of the present invention. FIG. 3B is a cross-sectional view taken along the line D-D of FIG. 3A. FIG. 4 is a schematic plan view illustrating a method of manufacturing a semiconductor laser device according to an embodiment of the present invention. FIG. 5A is a schematic plan view illustrating a method of manufacturing a semiconductor laser device according to an embodiment of the present invention. FIG. 5B is a cross-sectional view taken along line EE of FIG. 5A. FIG. 6 is a graph showing the dispersion of the FFP optical axis misalignment angle in the horizontal direction in the semiconductor laser device groups of the example and the comparative example. FIG. 7 is a graph showing the dispersion of the FFP optical axis misalignment angle in the vertical direction in the semiconductor laser device groups of the example and the comparative example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments shown below illustrate methods for embodying the technical idea of the present invention, and the present invention is not specified in the following embodiments. Further, in the following description, the same names and reference numerals indicate the same or the same members, and the detailed description will be appropriately omitted.

  1A to 5B are schematic views for explaining a method of manufacturing a semiconductor laser device according to the present embodiment. 1A, 2A, 3A, 4 and 5A are top views of the wafer. 2A and 3A are enlarged views of a part of the wafer 1 as in FIG. 1A. FIG. 1B is a cross-sectional view taken along line AA of FIG. 1A. 2B is a cross-sectional view taken along the line B-B of FIG. 2A, and FIG. 2C is a cross-sectional view taken along the line C-C of FIG. 2A. FIG. 3B is a cross-sectional view taken along the line DD of FIG. 3A. FIG. 5B is a cross-sectional view taken along the line EE of FIG. 5A.

As shown in FIGS. 1A to 5B, the method of manufacturing a semiconductor laser device 100 according to this embodiment includes the steps of preparing a wafer 1 on which a semiconductor laminate 20 having an active layer 22 is formed on a substrate 10; In the semiconductor laminate 20, the ridge 20a extending in the X direction, the plurality of first recesses 31 extending in the Y direction separated from the ridge 20a and intersecting the X direction, and the ridge 20a closer to the ridge 20a than the first recess 31 And forming a light emitting surface 71 by cleaving the wafer 1 along the plurality of first recesses 31. As shown in FIG. The second concave portion 32 is formed to be located in the vicinity of the light emitting surface 71. The length in the Y direction of the second recess 32 is L, and the length in the Y direction of the portion where the Y coordinate of the second recess 32 in the Y direction coincides with the first recess 31 is L _a (0 <L _a ) and was at the _time, satisfy the relationship of _{L a <(L-L a} ). The details will be described below.

(Step 1)
First, as shown in FIGS. 1A and 1B, the wafer 1 is prepared. The wafer 1 has a substrate 10 and a semiconductor laminate 20 formed on the substrate 10. The semiconductor stack 20 includes at least an active layer 22. For example, the n-side semiconductor layer 21, the active layer 22, and the p-side semiconductor layer 23 are formed in this order from the substrate 10 side. In order to cleave the wafer 1 in a process to be described later, it is preferable to use a material having cleavage properties for the substrate 10. As the substrate having cleavage property, for example, a nitride semiconductor substrate such as GaN can be used that has the same crystal structure as that of the semiconductor stacked body 20. The n-side semiconductor layer 21, the active layer 22, and the p-side semiconductor layer 23 are formed using, for example, a nitride semiconductor such as GaN, InGaN, or AlGaN. The n-side semiconductor layer 21 includes an n-type semiconductor layer and may include an undoped layer. The p-side semiconductor layer 23 includes a p-type semiconductor layer and may include an undoped layer. The active layer 22 can have a multiple quantum well structure or a single quantum well structure. The semiconductor laminate 20 includes, for example, an n-side cladding layer, an n-side light guide layer, an active layer 22, a p-side electron confinement layer, a p-side light guide layer, a p-side cladding layer, and a p-side contact layer in this order from the substrate 10 side. Have.

(Step 2)
Next, as shown in FIGS. 2A to 2C, a ridge 20 a extending in the X direction, a first recess 31, and a second recess 32 are formed in the semiconductor stack 20. Here, the ridge 20 a can be obtained by removing a part of the p-side semiconductor layer 23 from the upper side of the wafer 1 while leaving a part to be a ridge later. In addition, the p-side semiconductor layer 23, the active layer 22, and a portion of n from the upper side of the wafer 1 except for the portions to be the first and second recesses after the first recess 31 and the second recess 32 respectively. It can be obtained by removing the side semiconductor layer 21.

  When the wafer 1 is viewed from above, the first recess 31 and the second recess 32 are formed apart from the ridge 20 a, and the first recess 31 extends in the Y direction intersecting the X direction. Are disposed closer to the ridge 20 a than the first recess 31. The first recess 31 is formed at a cleavage cleavage position in order to cleave the first recess 31 as a guide as described later. The second recess 32 is formed in the vicinity of the light emitting surface of each of the semiconductor laser elements to be obtained later. Although the wafer 1 can be divided and singulated in a direction perpendicular to the cleavage direction as described later, the third concave portion 33 may be formed at the dividing position in the wafer 1. The third recess 33 is a linear recess extending in a direction parallel to the ridge 20a.

When the length in the Y direction of the second recess 32 is L and the length in the Y direction of the portion where the Y coordinate of the second recess 32 matches the first recess 31 is L _a (0 <L _a ), L The relationship of _a <(L−L _a ) is satisfied. That is, the length of the portion where the Y coordinate of the second recess 32 coincides with the first recess 31 (the length of the portion where the second recess 32 overlaps the first recess 31 in the direction perpendicular to the Y direction) It is preferable that it is half or less of the length of 2 concave part 32.

The separation distance of the first recess 31 from the ridge 20a is larger than the separation distance of the second recess 32 from the ridge 20a. Therefore, the distance between the two first recesses 31 sandwiching the ridge 20 a can be increased by arranging the first recesses 31 used for cleavage so as to reduce the overlap with the second recesses 32. Thereby, it becomes easy to cut along the cleavage plane (typically, the cleavage plane of the substrate 10) of the crystal constituting the wafer 1. This is because the first concave portion 31 has a fixed width, so the surface that is actually broken does not necessarily coincide with the cleavage surface. Therefore, by separating the first recesses 31 adjacent to each other across the ridge 20a, it is possible to reduce the deviation between the surface that is actually broken and the cleavage surface. In addition, if there is a portion where the first concave portion 31 and the Y coordinate coincide with each other, the second concave portion 32 adversely affects the cleavage and a step is generated on the cleavage end surface, or between the first concave portion 31 and the second concave portion 32. Cracks may occur. By setting L _a <(L−L _a ), this can be suppressed. As described above, an abnormality with a step is less likely to occur on the cleavage surface, and it becomes possible to obtain a flat cleavage facet, so that the optical axis deviation in the vertical direction can be reduced, and the light emission efficiency is improved. be able to. Further, the optical axis deviation of the FFP in the horizontal direction can be reduced by stably and substantially vertically splitting the ridge 20a in the top view.

Specifically, the distance D ₁ of the between the first recess 31 adjacent in the Y direction across the ridge 20a is preferably larger than the length L ₁ of the first recess 31. Furthermore, it is preferable that the distance D ₁ be larger than twice the length L ₁ of the first recess 31. In order to make the first concave portion 31 have a role of a cleavage guide, the distance D ₁ is set such that at least one, preferably two, of the first concave portions 31 are included in one direction in a region to be one semiconductor laser device. It is preferable to do. In this case, the upper limit of the distance D ₁ may be a degree less than the length of the Y direction of one semiconductor laser element. The distance _{D 1} is preferably not less than 130 .mu.m. Also, Y-direction length L ₁ of the first recess 31 is preferably smaller than the Y-direction of the length L ₂ of the second recess. The length L ₁ can be, for example, 2 μm or more. It is preferable that the first recess 31 be in the shape of a groove, and the shape in a plan view thereof be a shape extended in the Y direction. As such a shape, for example, a rectangle having a side along the Y direction as a long side can be mentioned. The width (length in the X direction) of the first recess 31 is, for example, about 0.5 μm to 2 μm. It is preferable that the end of the first recess 31 on the side far from the ridge 20a be located in a portion that is to be a side surface of the semiconductor laser device (a side extending in the Y direction in top view). When providing the 3rd recessed part 33 as shown to FIG. 2A, it is preferable that the 1st recessed part 31 and the 3rd recessed part 33 are connected. Thus, easily increase the distance D _1. At this time, the length from one end to the other end of two adjacent first recesses 31 with the third recess 33 interposed therebetween (in the example shown in FIG. 2A, twice the length L ₁ of the first recess 3 plus the width of the recess 33), it is preferable to increase the distance D ₁ of about smaller than the length L ₂ of the second recess 32. The Y direction is preferably a direction substantially perpendicular to the X direction.

In addition, if the first concave portion 31 moves away from the ridge 20a by increasing the distance between the first concave portions 31 and a gap where there is no concave portion between the ripple reduction groove and the light emitting surface, a horizontal FFP is generated. It was confirmed that ripples occur. This is considered to be due to stray light leaking from the gap where there is no recess. For this reason, it is preferable that the length L _{a of the} portion where the Y coordinate of the second concave portion 32 matches the first concave portion 31 be 0 <L _a . As a result, leakage of light from the optical waveguide region (ridge 20 a) of the semiconductor laser device can be suppressed by both the first recess 31 and the second recess 32, so that ripples can be reduced.

By making the length L _a greater than 0, light leakage can be suppressed more reliably. On the other hand, if the length L _a is large, a step or shift is easily generated on the cleavage end face, and therefore, the length L ₂ (L) and the length L _a of the second concave portion 32 satisfy L _a <(L ₂ −L _a It is preferable to satisfy the relationship of Moreover, it is preferable that length _La is 10 micrometers or less. The ratio of the length L _{a to} the length L ₂ is preferably 14% or less.

  In order to effectively reduce the ripple of FFP, it is desirable to arrange the second recess 32 in the vicinity of the light exit surface. Therefore, the distance between the first recess 31 and the second recess 32 (the shortest distance in the X direction) is preferably 30 μm or less, and more preferably 10 μm or less. The distance between the first recess 31 and the second recess 32 can be, for example, 0.5 μm or more. As shown in FIG. 2A, the second recess 32 may be shaped such that the end on the side far from the ridge 20a is located farther from the first recess 31 compared to the other portions. The second concave portion 32 is more likely to affect the cleavage end face as the distance to the first concave portion 31 becomes shorter, but such a shape can reduce the influence on the cleavage end face. Further, the end of the second recess 32 on the side far from the ridge 20a may be located at a portion that is to be a side surface of the semiconductor laser device (a side extending in the Y direction in top view). When providing the 3rd recessed part 33 as shown to FIG. 2A, the 2nd recessed part 32 and the 3rd recessed part 33 may be connected.

  Further, in order to reduce the ripple more effectively, it is preferable to provide the second recess 32 in the vicinity of the ridge 20a. It is desirable that the shortest distance between the second recess 32 and the ridge 20a is 15 μm or less, more preferably 10 μm or less, and still more preferably 2 μm or less. The second recess 32 may be in contact with the ridge 20a, but the distance between the second recess 32 and the ridge 20a may be, for example, 0.5 μm or more. The width of the second recess 32 is, for example, about 0.5 μm to 2 μm.

  The shape of the second concave portion 32 in plan view is preferably a shape which easily scatters / refracts light leaking from the optical waveguide region and guided in the semiconductor laser device in a direction different from the main beam of the laser device. Specifically, it is preferable that the direction of the tangent line is a circular or elliptical shape that changes continuously, or a shape having a side that is inclined with respect to the light emission surface. The second recess 32 is preferably a continuous groove so as to easily suppress the stray light leakage. For example, as shown in FIG. 2A, the second recess 32 can be formed as a groove whose plan view shape is a wavy line. In the case of such a wavy groove, a crack is likely to occur between the apex of the corner closest to the first recess 31 and the first recess 31. Therefore, it is preferable to suppress the number of such corner portions provided in the portion where the first concave portion 31 and the Y coordinate coincide. For example, as shown in FIG. 2A, it is 2 or less. Further, the second recess 32 can be shaped and disposed in line symmetry with respect to the ridge 20a. The second recess 32 may be provided not only in the vicinity of the light emission surface but also in the vicinity of the light reflection surface.

  Preferably, the depth of the second recess 32 is such that it can scatter light leaked from the optical waveguide. The same depth is preferable for the first recess 31 as well. The first recess 31 and the second recess 32 can be formed, for example, by removing the p-side semiconductor layer 23 and a part of the active layer 22 to expose the n-side semiconductor layer 21. The second concave portion 32 can effectively scatter the light leaked in the lateral direction from the active layer 22 by setting the bottom surface to a depth at least reaching the n-side semiconductor layer 21. In particular, in the case of a split light confinement type (SCH type) semiconductor laser device, it is preferable that the bottom surface of the second recess 32 reaches below the lower surface of the n-side light guide layer. The depth of the second recess 32 is preferably such that the second recess 32 does not reach the substrate 10. The depth of the second recess 32 can be, for example, about 0.5 μm to 10 μm, and further, can be about 1 μm to 5 μm.

  The second recess 32 is preferably formed by etching using a patterned mask. Specifically, a mask having an opening at a position where the second recess 32 is to be formed can be formed on the semiconductor stack 20, and etching such as dry etching can be performed. The same is applied to the first recess 31, which makes it possible to form the recess more accurately than in the case where the groove is formed by laser processing.

  The ridge 20 a is formed, for example, by removing a part of the p-side semiconductor layer 23. For example, the p-side contact layer and a part of the p-side cladding layer are etched away leaving a ridge-like portion, to form a ridge 20a for forming an optical waveguide. The width of the ridge 20a can be about 1 μm to 100 μm, and can be about 1 μm to 3 μm, for example. The height of the ridge 20a (depth removed by etching or the like) is, for example, 0.1 μm to 2 μm. The length (length in the X direction) of the ridge 20 a in the resonator direction is preferably set to about 100 μm to 2000 μm.

  Although the formation order of the ridge 20a, the first concave portion 31 and the second concave portion 32 does not matter, if the first concave portion 31 and the second concave portion 32 are formed collectively, it is possible to suppress an increase in the number of processes. In this case, the first recess 31 and the second recess 32 have the same depth.

  Before performing the cleavage process described later, each member necessary for the semiconductor laser device may be appropriately formed. For example, as shown in FIGS. 3A and 3B, the insulating film 40, the p electrode 51, the pad electrode 52, the n electrode 60, and the like can be formed. In FIG. 3A, each member is shown in a state of being transmitted through the insulating film 40. The insulating film 40 can be formed, for example, on substantially all of the surface of the semiconductor stack 20 except for the top surface of the ridge 20a. The insulating film 40 may be formed inside the first recess 31 and the second recess 32, but may be formed in a region other than the first recess 31 and the second recess 32. Preferably, no electrode is formed inside the first recess 31 and the second recess 32. The p electrode 51 can be formed, for example, to be in contact with the surface of the ridge 20 a exposed from the insulating film 40. A pad electrode 52 can be formed on the p electrode 51. An n electrode 60 can be formed on the back surface of the substrate 10. In the present embodiment, the substrate 10 is described as an n-type semiconductor, but the present invention is not limited to this.

(Third step; cleavage step)
Next, as shown in FIG. 4, the light emitting surface 71 is formed by cleaving the wafer 1 along the plurality of first recesses 31. The wafer 1 is cleaved into, for example, bar-like pieces. A surface opposite to the light emitting surface 71 is a light reflecting surface 72.

  Cleavage forms, for example, a groove (for example, a groove formed by laser irradiation) along the cleavage surface in the first recess 31 or at the end of the wafer, and presses the pressing member against the lower surface of the substrate 10 to apply pressure. By doing. A blade (blade) or a roller can be used as the pressing member. A mirror such as a dielectric multilayer film can be formed on the light emitting surface 71 and the light reflecting surface 72.

(The 4th process; individualization process)
Next, as shown in FIGS. 5A and 5B, the small pieces of the wafer obtained by cleavage are divided in a direction substantially perpendicular to the cleavage plane (a direction substantially parallel to the extending direction of the ridge 20a) to form individual semiconductor laser devices Separate into 100 pieces. Such division is performed by, for example, laser scribing or cutter scribing and breaking small pieces of the wafer. The order of the third and fourth steps can be interchanged. That is, cleavage may be performed after being divided in a direction substantially parallel to the extending direction of the ridge 20a. When forming a mirror, it is preferable to form in the state of a bar-like small piece. Therefore, it is preferable to further include a singulation step of cleaving the wafer 1 in the cleaving step to obtain bar-shaped pieces and thereafter separating the pieces in the X direction.

  According to the manufacturing method of the embodiment described above, since the first recess 31 used for cleavage is provided away from the ridge 20 a to such an extent that the overlap with the second recess 32 becomes small, cleavage of crystals constituting the wafer 1 It is easy to be cut along the surface, and a good cleavage surface can be obtained. In addition, since stray light inside the semiconductor laser device 100 can be prevented from being extracted to the outside by the second concave portion 32, ripples of FFP of the obtained semiconductor laser device 100 can be reduced.

The semiconductor laser device of the example was manufactured as follows.
First, prepare a wafer. The wafer has an n-type GaN substrate, on which an n-side GaN-based semiconductor layer, an active layer, and a p-side GaN-based semiconductor layer are sequentially stacked.
Next, a ridge, a first recess, and a second recess are formed. The second recess is wavy as shown in FIG. 2A, and is disposed so that the Y coordinate, which is the coordinate in the Y direction, partially coincides with the first recess when the extending direction of the ridge is the X direction. ing. The length of the first recess is 10 μm, and the length of the second recess is 72 μm. The length of the portion where the first recess of the second recess and the Y coordinate coincide is 10 μm, that is, occupies about 14% of the entire length of the second recess. The shortest distance between the first recess and the second recess is 0.5 μm. The distance between the first recesses is 130 μm.
Next, the wafer is cleaved along the first recess. Among the cleavage facets obtained by cleavage, the side provided with the second recess is the light emission surface, and the opposite side is the light reflection surface. Thereafter, the semiconductor laser element is cut in a direction substantially perpendicular to the cleavage plane to obtain a singulated semiconductor laser device.

  As a comparative example, the length of the first recess is 60 μm, the distance between the first recesses is 10 μm, the length of the second recess is 27 μm, and the length at which the Y coordinate of the second recess matches the first recess is The same semiconductor laser device as that of the example was manufactured except that it was 25 μm.

  The characteristics of the semiconductor laser devices of the example and the comparative example obtained as described above are shown in FIG. 6 and FIG. FIGS. 6 and 7 respectively measure FFP for a plurality of semiconductor laser devices obtained from one wafer, and plot the vertical axis as the optical axis offset angle in FFP and the horizontal axis as cumulative distribution probability. That is, from FIGS. 6 and 7, it is possible to read the degree of variation of the optical axis misalignment angle for a plurality of semiconductor laser devices obtained from one wafer. FIG. 6 shows the optical axis misalignment angle in the horizontal direction FFP, and FIG. 7 shows the optical axis misalignment angle in the vertical direction FFP. In FIG. 6 and FIG. 7, the semiconductor laser device group of the example is shown by black circles, and the semiconductor laser device group of the comparative example is shown by gray triangles.

  As shown in FIG. 6, with respect to the optical axis deviation in the horizontal direction, many semiconductor laser element groups of the embodiment are closer to 0 ° than the semiconductor laser element group of the comparative example. It is considered that this is because cleavage was performed at an angle closer to the perpendicular to the extending direction of the ridge. When a plurality of semiconductor laser device groups were extracted from each semiconductor laser device group and the angle of the light emitting surface with respect to the ridge was measured, the semiconductor laser device of the comparative example varied between 85 ° and 87 °. It could be confirmed that it was within between 90 ° and 90 °.

  Further, in FIG. 7, an approximation line was drawn for each semiconductor laser element group, and the inclination and the intercept were obtained. The semiconductor laser device group of the example had an inclination of 0.40 and an intercept of +0.34, and the semiconductor laser device group of the comparative example had an inclination of 0.61 and an intercept of −0.23. It can be seen that the variation of the semiconductor laser device group of the example is smaller than that of the semiconductor laser device group of the comparative example. The optical axis misalignment angle in the FFP in the vertical direction has a large variation due to the occurrence of a step or the like on the cleavage facet. Therefore, by using the manufacturing method of the embodiment, it is possible to suppress the occurrence of a step or the like at the cleavage facet, and as a result, it is considered that the variation of the optical axis deviation in the FFP in the vertical direction can be reduced.

DESCRIPTION OF SYMBOLS 1 wafer 10 substrate 20 semiconductor laminated body 20a ridge 21 n side semiconductor layer 22 active layer 23 p side semiconductor layer 31 1st recessed part 32 2nd recessed part 33 3rd recessed part 40 insulating film 51 p electrode 52 pad electrode 60 n electrode 71 light emission Face 72 light reflecting face 100 semiconductor laser element

Claims (6)

Preparing a wafer having a semiconductor laminate having an active layer formed on a substrate;
In the semiconductor laminate, a ridge extending in the X direction, a plurality of first recesses spaced apart from the ridge and extending in the Y direction intersecting the X direction, and the ridge closer to the ridge than the first recess Forming a plurality of second recesses to be arranged;
Cleaving the wafer to form a light emitting surface by cleaving the wafer along the plurality of first recesses;
A method of manufacturing a semiconductor laser device comprising
The second recess is formed in the vicinity of the light exit surface,
The length in the Y direction of the second recess is L, and the length in the Y direction of the portion of the second recess where the Y coordinate, which is the coordinate in the Y direction, matches the first recess is La (0 < when the La), meet the relationship of La <(L-La),
The second recess is provided continuously from the end on the ridge side to the end on the side far from the ridge,
A method of manufacturing a semiconductor laser device, wherein a terminal end far from the ridge is arranged to be farther from the first recess as compared with the other portion of the second recess .   The method for manufacturing a semiconductor laser device according to claim 1, wherein a distance between the first recesses adjacent in the Y direction across the ridge is larger than a length of the first recess.   The method for manufacturing a semiconductor laser device according to claim 1, wherein a distance between the first concave portions adjacent to each other in the Y direction across the ridge is 130 μm or more.   The method of manufacturing a semiconductor laser device according to any one of claims 1 to 3, wherein the length La is 10 μm or less.   The semiconductor according to any one of claims 1 to 4, further comprising: a singulation step of cleaving the wafer in the cleaving step to obtain bar-shaped pieces and thereafter separating the pieces in the X direction. Method of manufacturing a laser device   The method for manufacturing a semiconductor laser device according to any one of claims 1 to 5, wherein a length of the first concave portion in the Y direction is smaller than a length of the second concave portion in the Y direction.

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