JP2018117015A - Nitride semiconductor laser element and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a yield by stabilizing a chip shape.SOLUTION: A manufacturing method of a nitride semiconductor laser element 10 formed by laminating a nitride semiconductor layer 12 including a light emission layer that comprises a resonator end face on a nitride semiconductor substrate 11, includes steps of: preparing a wafer 20 in which the nitride semiconductor layer 12 is laminated on the nitride semiconductor substrate 11; and forming a first division guide groove 22 that includes a plural number of punctiform parts discretely arranged along a first direction where a surface as the resonator end face is extended while being cleaved on the nitride semiconductor layer 12. The plural number of punctiform parts includes a shape of a second direction width orthogonal to the first direction in which a tip end side is narrower than a rear end side. The tip end side of each punctiform part is arranged opposite to the rear end side of the other punctiform part adjacent to the punctiform part.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a nitride semiconductor laser device and a method for manufacturing the same.

Conventionally, a blue nitride semiconductor laser element having a structure in which a group III nitride semiconductor layer is grown on a GaN substrate is known. The nitride semiconductor laser element includes an n-type cladding layer (lower cladding layer), an n-type guide layer (lower guide layer), an active layer having a multiple quantum well structure, and a p-type guide layer (upper guide layer) from the GaN substrate side. ) And a p-type cladding layer (upper cladding layer). The emission wavelength is adjusted by the composition of the quantum well layer.
A substrate made of a group III nitride semiconductor, such as a GaN substrate, is less cleaved than a GaAs substrate or the like conventionally applied to a light emitting diode or a laser diode. For this reason, in the step of dividing the wafer into individual chips, the dividing position is shifted from the line to be divided, and the chip shape is not stable.

  Therefore, Patent Document 1 discloses a method of obtaining individual laser elements by dividing a wafer according to the following procedure. That is, in the method described in Patent Document 1, an n-type semiconductor layer including an AlGaN layer, a light-emitting layer including In, and a p-type semiconductor layer are sequentially laminated on a group III nitride semiconductor substrate. By selectively etching from the p-type semiconductor layer side along the planned line, an etching groove that exposes the AlGaN layer along the planned division line is formed. Further, a division guide groove is formed along the planned division line in the exposed AlGaN layer. Then, the individual elements are obtained by dividing the wafer along the divided guide grooves.

JP 2009-81428 A

However, even with the method described in Patent Document 1, it is difficult to accurately divide individual elements according to the planned division line, and the chip shape is stabilized by shifting the division position from the planned division line. However, the yield was reduced.
Accordingly, an object of the present invention is to provide a method of manufacturing a nitride semiconductor laser device that can stabilize the chip shape and improve the yield.

  In order to solve the above-described problem, an embodiment of a method of manufacturing a nitride semiconductor laser device according to the present invention includes a nitride semiconductor substrate including a nitride semiconductor layer including a light emitting layer having a resonator end face. A method of manufacturing a nitride semiconductor laser device comprising: preparing a wafer substrate in which the nitride semiconductor layer is laminated on the nitride semiconductor substrate; and cleaving the nitride semiconductor layer on the wafer substrate. Forming a first divided guide groove including a plurality of point-like portions discretely arranged along a first direction in which a surface serving as the resonator end surface extends, and the plurality of points Each of the other portions has a shape in which the front end side is narrower than the rear end side with respect to the width in the second direction orthogonal to the first direction, and the front end side of the point-like portion is adjacent to the point-like portion. Arranged opposite the rear end side of the point-like portion. .

  As described above, when the nitride semiconductor laser device is manufactured, a plurality of dot-like portions having a shape whose front end side is narrower than the rear end side are formed on the nitride semiconductor layer of the wafer substrate along the first direction which is the cleavage direction. The first divided guide grooves arranged discretely are formed. Then, the plurality of dot-like portions constituting the first divided guide groove are the other dot-like portions in which the end portion (tip portion) having the narrower width of the dot-like portion is adjacent to the dot-like portion in the first direction. Is formed so as to face the wider end (rear end). As a result, when the wafer substrate is cleaved, the cleaving proceeds regularly starting from the end of the narrower dot-like width. Even if the cleavage progress line is bent, as a result of the trajectory correction of the cleavage progress line at the wide end of the other punctiform part facing the cleavage direction, the cleavage trajectory is relatively relatively small as a whole. It will be straight. Therefore, the chip shape when the wafer substrate is separated can be stabilized.

  In the method for manufacturing a nitride semiconductor laser element, the first divided guide groove may be configured so that the point-like portion extends from the tip side to the rear end side of the other point-like portion adjacent to the point-like portion. The method may further include a step of cleaving the wafer substrate to form a surface to be the resonator end surface. As described above, by dividing the wafer substrate by cleaving according to the first division guide groove, it is possible to form a flat resonator end face with high reflectivity.

  Furthermore, in the above method for manufacturing a nitride semiconductor laser device, the point-like portion has a shape that gradually becomes narrower from the rear end side toward the front end side with respect to the width in the second direction. Also good. In this case, the most distal portion of the dotted portion can be reliably set as the starting point of cleavage. Since it is possible to prevent the cleavage progress line from being bent from the middle of the dotted portion, division along the planned cleavage line becomes possible.

In the method for manufacturing a nitride semiconductor laser element, the point-like portion may have a sharp shape on the tip side. In this case, one point of the tip part of the point-like part can be used as the starting point of cleavage. Therefore, if the tip position of the dotted portion is arranged on the planned cleavage line, the wafer substrate can be divided straight according to the planned cleavage line.
Furthermore, in the above method for manufacturing a nitride semiconductor laser device, the point-like portion gradually increases from the rear end side toward the front end side with respect to the depth in the direction orthogonal to the first direction and the second direction. You may have the shape which becomes shallow at least in part. In this case, the forefront part of the point-like part can be set as the starting point of cleavage more reliably.

  Furthermore, in the method for manufacturing the nitride semiconductor laser element, the first divided guide groove may be formed by laser processing in the step of forming the first divided guide groove. In the method for manufacturing the nitride semiconductor laser element, the first divided guide groove may be formed by dry etching in the step of forming the first divided guide groove. In either case, the first divided guide groove can be formed easily and appropriately. When the first divided guide groove is formed by laser processing, the depth of the dotted portion can be gradually decreased from the rear end side toward the front end side. In this case, the forefront part of the point-like part can be set as the starting point of cleavage more reliably. On the other hand, when the first divided guide groove is formed by dry etching, it is easy to make the point-like portion an arbitrary shape, and the degree of freedom of the shape of the point-like portion is high.

Furthermore, in the method of manufacturing the nitride semiconductor laser element, in the step of forming the first divided guide groove, the first divided guide groove is formed at a location excluding the upper side of the optical waveguide constituting the resonator. A point-like portion may be formed. In this case, the dot-like portion can be formed at a position that does not affect the emission of the laser light.
In the method for manufacturing a nitride semiconductor laser device, the first division may include a step of forming a plurality of optical waveguides arranged adjacent to each other in the first direction with respect to the nitride semiconductor layer. In the step of forming the guide groove, the first divided guide is set such that a separation distance between the dotted portions adjacent to each other in the first direction is equal to or less than a separation distance between the optical waveguides adjacent to each other in the first direction. You may form the said dot-like part of a groove | channel. That is, a plurality of dot-like portions may be formed at an interval narrower than the chip width that is singulated. In this case, the chip shape can be stabilized in all the separated elements, and the yield can be improved.

  Furthermore, in the above method for manufacturing a nitride semiconductor laser device, a step of forming a second divided guide groove along the second direction on the nitride semiconductor layer, and the wafer substrate according to the second divided guide groove And a step of dividing. By dividing the wafer substrate according to the second divided guide groove, a nitride semiconductor laser device having a chip width equal to the separation distance in the first direction of the second divided guide groove can be manufactured.

According to another aspect of the nitride semiconductor laser device of the present invention, a nitride semiconductor layer including a light emitting layer having a cavity end face extending in a first direction formed by cleavage is formed on a nitride semiconductor substrate. A nitride semiconductor laser element formed by stacking, wherein a width of a second direction orthogonal to the first direction is a part of a side of the nitride semiconductor layer extending in the first direction. Different recesses are formed on one end side and the other end side.
The side extending in the first direction of the nitride semiconductor layer corresponds to the upper side of the resonator end face. The nitride semiconductor laser element in which the concave portion having the above shape is formed on the side is a nitride semiconductor laser element having a resonator end face cleaved from the concave portion, and has a stable chip shape.

Furthermore, one aspect of the wafer substrate according to the present invention is a wafer substrate in which a nitride semiconductor layer including a light emitting layer is laminated on a nitride semiconductor substrate, and the nitride substrate is formed on the nitride semiconductor layer of the wafer substrate. The first divided guide grooves including a plurality of point-like portions discretely arranged along a first direction in which a surface to be a resonator end surface extends after cleavage is formed, and the plurality of point-like portions are respectively Regarding the width in the second direction orthogonal to the first direction, the tip side has a shape narrower than the rear end side, and the tip side of the point-like portion is adjacent to the point-like portion. Is arranged to face the rear end side.
Such a wafer substrate has a relatively straight cleaved orbit when cleaved. That is, the chip shape when the wafer substrate is separated can be stabilized.

  According to the present invention, it is possible to divide a wafer by cleaving with high accuracy according to a cleaving line. Therefore, the chip shape can be stabilized and the yield can be improved.

It is a perspective view which shows the structural example of the nitride semiconductor laser element in this embodiment. It is a figure explaining the manufacturing process of a nitride semiconductor laser element. It is a figure explaining the manufacturing process of a nitride semiconductor laser element. It is a figure explaining the manufacturing process of a nitride semiconductor laser element. It is a figure explaining the manufacturing process of a nitride semiconductor laser element. It is an example of a division | segmentation guide groove. It is a figure which shows the shape of a division | segmentation guide groove. It is a comparative example of a division | segmentation guide groove. It is a figure which shows the formation position of the division guide groove on a wafer substrate. It is a figure which shows the scribe mark which a nitride semiconductor laser element has.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration example of a nitride semiconductor laser element 10 in the present embodiment.
A nitride semiconductor laser element (hereinafter referred to as “chip”) 10 emits laser light in the direction of an arrow in the drawing when assembled in a semiconductor laser device and supplied with a predetermined injection current.
The chip 10 includes a substrate 11 having a chip width W. For example, the substrate 11 is a nitride semiconductor substrate made of a nitride semiconductor such as gallium nitride (GaN), aluminum nitride (AlN), or aluminum gallium nitride (AlGaN). A semiconductor layer (semiconductor laminated structure) 12 is formed on the substrate 11. The semiconductor layer 12 is a nitride semiconductor layer formed by crystal growth on the main surface with the c-plane of the substrate 11 as the main surface.

The semiconductor layer 12 includes at least an active layer having a cavity length L to be a light emitting layer, an n-type semiconductor layer, and a p-type semiconductor layer. For example, the n-type semiconductor layer is disposed on the substrate 11 side with respect to the active layer, and the p-type semiconductor layer is disposed on the side opposite to the substrate 11 with respect to the active layer. Note that the positional relationship between the n-type semiconductor layer and the p-type semiconductor layer may be reversed. In the active layer, electrons are injected from the n-type semiconductor layer and holes are injected from the p-type semiconductor layer, and these are recombined in the active layer, whereby light is generated from the active layer.
Of the n-type semiconductor layer and the p-type semiconductor layer, a stripe-shaped ridge portion 13 is formed in a layer located on the side farther from the substrate 11 than the active layer. The ridge portion 13 is a current confinement portion for confining current, and is located above the optical waveguide formed in the active layer and extending along the m-axis direction.

A pair of resonator end faces facing each other are formed at both ends in the extending direction of the ridge portion 13. The resonator end faces are surfaces in which a reflection film is formed on the surface formed by cleavage, and the laser can be emitted by reflecting light by these resonator end faces. The resonator end surface is formed along the m-plane. As in this embodiment, the resonator end face is preferably a cleavage plane. The reason is that the surface formed by cleaving is less rough than the surface formed by means other than cleaving, such as a laser cut surface, and the high reflectivity necessary for the resonator end face can be secured. It is.
In the present embodiment, the case where the c-plane of the substrate 11 is the main surface and the m-plane is the resonator end surface is described. However, the m-plane may be the main surface and the c-plane may be the resonator end surface.

Next, a manufacturing process of the chip 10 shown in FIG. 1 will be described with reference to FIGS.
First, a wafer substrate (hereinafter simply referred to as “wafer”) 20 in which a large number of ridge portions 13 to be optical waveguides are arranged in parallel is prepared, and the wafer 20 is divided into sizes that can be cleaved as shown in FIG. Thus, a divided wafer (divided substrate) 21 is formed. Here, although not particularly illustrated, a plurality of ridge portions 13 extend in the m-axis direction on the wafer 20, and the plurality of ridge portions 13 are arranged in parallel at a predetermined interval in the a-axis direction. .

Next, as shown in FIG. 3, a split guide groove (first split guide groove) 22 for cleavage is formed on the surface of the split wafer 21 by, for example, laser processing. Further, a cleaving flaw may be formed on the a-axis direction end of the divided wafer 21 with, for example, a diamond cutter. In the present embodiment, the case where the division guide groove 22 is formed by laser processing will be described. However, the division guide groove 22 may be formed by dry etching.
A plurality of the division guide grooves 22 extend in the a-axis direction, which is the cleavage direction, and the plurality of division guide grooves 22 are arranged parallel to each other at a predetermined interval in the m-axis direction. Each division guide groove 22 is configured by a plurality of dot-like portions that are discretely arranged along the cleavage direction. The shape of the dotted portion of the division guide groove 22 will be described in detail later.

Next, for example, the blade is pushed up in accordance with the divided guide groove 22, and the divided wafer 21 is cleaved along the divided guide groove 22. The cleavage proceeds along the m-plane, and a bar-shaped chip 23 as shown in FIG. 4 is formed. At this time, a reflection film is formed on each of both end faces in the m-axis direction which are cleavage planes. Thereby, a resonator end face is formed.
Next, a divided guide groove (second divided guide groove) 24 is formed on the bar-shaped chip 23 in the direction perpendicular to the first direction and along the m-axis direction in which the optical waveguide extends. And according to the division | segmentation guide groove 24, the bar-shaped chip | tip 23 is divided | segmented by laser dicing, for example. Thereby, as shown in FIG. 5, the chip | tip 10 which has a light emission part separately is formed.
The cleavage direction (a-axis direction) corresponds to the first direction, and the direction in which the divided guide groove 24 extends (m-axis direction) corresponds to the second direction.

Hereinafter, the shape of the dotted portion of the division guide groove 22 will be described in detail.
As shown in FIG. 6, the dotted portions are arranged in a line on the planned cleavage line 31 set along the cleavage direction, and the width in the direction orthogonal to the planned cleavage line 31 is in the direction of cleavage progress. The front end side has a narrower shape than the rear end side. More specifically, the point-like portion has a shape that gradually becomes narrower in the cleaving direction in plan view. Moreover, a dotted | punctate part has the shape where the front end side of the advancing direction of cleavage is sharp. For example, each point-like portion can be a scissors shape (tears) having a round shape on the rear end side in the cleaving direction in a plan view and a sharp shape on the front side in the cleaving direction. In this case, the sharp tip of each point-like part can be arranged on the planned cleavage line 31. Note that the angle of the tip of the point-like part may be an arbitrary angle.

The split guide groove 22 composed of a plurality of point-like portions having the above-mentioned shape is arranged on the planned cleavage line 31 and the cleavage progress line 32 is compared along the planned cleavage line 31 by performing cleavage according to the planned cleavage line 31. Can be straight.
The GaN substrate used for the substrate 11 of the chip 10 in the present embodiment is poor in cleavage as compared with other diode growth substrates such as gallium arsenide (GaAs). One of the reasons is that defects due to impurities exist in the GaN substrate. When a GaN substrate is used, even if an attempt is made to cleave the wafer in an arbitrary crystal plane direction such as the c-plane or the m-plane to form a wafer bar, the wafer cannot be cut straight during cleavage due to the defects. In other words, the dividing line is bent at a position where a defect exists, and the wafer may be broken stepwise or obliquely.

  Therefore, in the present embodiment, as described above, the split guide groove 22 for cleavage is a pattern in which a plurality of dotted portions are discretely arranged along the cleavage direction, and the shape of the dotted portions is sharp. It was made into the shape provided with the location and the location which is not so. And each point-like part arrange | positions the sharp location in the front end side of the advancing direction of cleavage, and the location which is not so in the rear end side. In this case, as shown in FIG. 7 (a), cleavage always proceeds starting from a sharp spot of the point-like portion.

The pointed portion has a sharp one end opposed to the other end formed wider than the other pointed portion adjacent to the pointed portion. Therefore, even if the cleaving progress line is bent due to a defect contained in the GaN substrate, the cleaved trajectory bent from the sharp one end is at the wide end of the other adjacent point-like part. The trajectory is corrected.
As described above, by performing regular cleavage, the cleavage path as a whole becomes relatively straight. That is, the cleavage progress line 32 can be substantially linear along the planned cleavage line 31. Here, it is preferable to set the pitch between adjacent point-like portions within a range where the bending of the cleavage line can be allowed. Thereby, it is possible to divide the wafer straight within an allowable range without greatly deviating from the planned cleavage line 31.

Further, as shown in FIG. 7B, it is preferable that the dot-like portion is formed so that the groove depth gradually becomes shallower toward the progressing direction of cleavage at least in part. In this case, since the starting point of cleavage becomes one point of the sharp one end of the point-like part, the cleavage path can be more straightened more appropriately.
FIG. 8A and FIG. 8B are comparative examples of divided guide grooves having point-like portions different in shape from the divided guide grooves 22 in the present embodiment. The division guide groove 122 shown in FIG. 8A is an example in which elliptical point-like portions in a plan view are arranged in a line with the major axis direction coinciding with the cleavage direction. Divided guide grooves 222 shown in FIG. 8B are examples in which rectangular dot-shaped portions in a plan view are arranged in a line with the long side direction aligned with the cleavage direction.

  In any case, since there is no sharp part and the following wide part like the dotted part of this embodiment, the starting point of cleavage is random, and regular cleavage is not performed. That is, the cleavage progress line is difficult to be divided along the planned cleavage line as indicated by the dotted line 132 in FIG. 8A and the dotted line 232 in FIG. 8B. Further, in the worst case, the trajectory correction at the adjacent point-like portions cannot be performed, and the cleavage progress line may deviate greatly from the planned cleavage line. For this reason, when the split guide groove formed of the dot-shaped portion having the shape as shown in FIGS. 8A and 8B is used, the chip shape is not stable and the yield is lowered.

On the other hand, in this embodiment, even if the GaN substrate includes a defect, as described above, the wafer can be divided straight according to the planned cleavage line. Therefore, it is possible to stabilize the chip shape and appropriately prevent a decrease in yield.
FIG. 9 is a diagram showing a positional relationship between the dotted portions of the divided guide grooves 22 and the ridge portions 13 corresponding to the optical waveguides. As shown in FIG. 9, the plurality of point-like portions of the divided guide groove 22 are formed on the surface of the divided wafer 21 (on the semiconductor layer 12) in the extending direction (a-axis direction) of the m-plane serving as the resonator end face. It is formed discretely along. In addition, each point-like portion of the divided guide groove 22 is formed at a place other than the upper part of the optical waveguide constituting the resonator, that is, a place where the ridge portion 13 is not formed.

  In the extending direction (a-axis direction) of the m-plane serving as the resonator end face, the separation distance between adjacent point-like portions is set to be equal to or less than the separation distance between adjacent optical waveguides (ridge portions 13). Further, in the extending direction (m-axis direction) of the optical waveguide (ridge portion 13), the distance between adjacent point-like portions (center-to-center distance) is set equal to the cavity length L of the chip 10. For example, as shown in FIG. 9, each point-like portion can be formed at the apex position of the chip 10 in plan view.

  When the chips 10 are formed from the divided wafers 21, first, the divided wafers 21 are divided by cleavage according to the divided guide grooves 22 to form bar-shaped chips 23. Next, the bar-shaped chip 23 is divided in a direction orthogonal to the cleavage direction by laser dicing or the like to form the chip 10. At this time, the bar-shaped chip 23 is divided at the center position of the dotted portion of the divided guide groove 22 to form the chip 10.

In the chip 10 formed in this way, as shown in FIG. 10, a scribe mark 22 a that is a part of a dotted portion remains at the apex portion of the semiconductor layer 12. The scribe mark 22a is a recess having a width in the m-axis direction (second direction) orthogonal to the a-axis direction (first direction) that is the cleavage direction, on one end side and the other end side in the cleavage direction. Note that, depending on the formation position and the separation distance of the dotted portions of the divided guide grooves 22 in the cleavage direction, the chip 10 that has been singulated is not the apex portion of the semiconductor layer 12 but the side that extends in the cleavage direction (resonance). The scribe mark 22a may remain in a part of the upper side of the vessel end face.
As described above, in the method for manufacturing a nitride semiconductor laser device according to the present embodiment, the wafer substrate can be divided with high accuracy according to the planned cleavage line. Therefore, the chip shape can be stabilized and the yield can be improved.

(Modification)
In the above embodiment, the case where the chip 10 includes the current confinement portion having the ridge structure has been described. However, the chip 10 may include a current confinement portion having a non-ridge structure (embedded structure). The buried structure is a structure in which an outside of a region serving as a current path of an injection current is cut out by etching, and another semiconductor layer is stacked as a buried layer on both sides of the region. Also in this case, the same effect as the above-described embodiment can be obtained.

  Furthermore, in the above-described embodiment, the case where the shape of the dotted portion of the divided guide groove 22 is a saddle shape (tears shape) has been described. However, the shape of the dotted portion is the tip in the cleaving direction in plan view. The side may be narrower than the rear end side, and may be, for example, a triangle or a sector. In addition, the shape of the point-like portion is not limited to a shape that gradually becomes narrower in the cleaving direction in plan view, and may have, for example, a step shape. Further, the shape of the point-like portion is not limited to a shape having a sharp tip in the cleaving direction in plan view, and may be, for example, a trapezoid.

  DESCRIPTION OF SYMBOLS 10 ... Nitride semiconductor laser element (chip), 11 ... Nitride semiconductor substrate, 12 ... Semiconductor layer, 13 ... Ridge part, 20 ... Wafer substrate, 21 ... Divided wafer, 22 ... Divided guide groove, 23 ... Bar-shaped chip

Claims (12)

A method of manufacturing a nitride semiconductor laser device, wherein a nitride semiconductor layer including a light emitting layer having a resonator end face is laminated on a nitride semiconductor substrate,
Preparing a wafer substrate in which the nitride semiconductor layer is laminated on the nitride semiconductor substrate;
A first divided guide groove including a plurality of point-like portions discretely arranged along a first direction that is cleaved and extends on the nitride semiconductor layer of the wafer substrate to serve as the resonator end face Forming a step, and
The plurality of point-like portions each have a shape in which the front end side is narrower than the rear end side with respect to the width in the second direction orthogonal to the first direction, and the tip side of the point-like portion is the point-like portion. A method of manufacturing a nitride semiconductor laser device, wherein the other point-like portion adjacent to the rear portion is disposed to face the rear end side.   According to the first divided guide groove, the wafer substrate is cleaved from the tip end side of the point-like portion toward the rear end side of the other point-like portion adjacent to the point-like portion, and the resonator end surface The method for manufacturing a nitride semiconductor laser device according to claim 1, further comprising a step of forming a surface to be formed.   3. The nitride semiconductor laser according to claim 1, wherein the point-like portion has a shape that gradually becomes narrower from the rear end side toward the tip end side with respect to the width in the second direction. 4. Device manufacturing method.   4. The method for manufacturing a nitride semiconductor laser element according to claim 1, wherein the point-like portion has a sharp shape on the tip side. 5.   The point-like portion has, at least in part, a shape that gradually becomes shallower from the rear end side toward the front end side with respect to a depth in a direction orthogonal to the first direction and the second direction. The method for manufacturing a nitride semiconductor laser element according to claim 1. In the step of forming the first divided guide groove,
6. The method for manufacturing a nitride semiconductor laser element according to claim 1, wherein the first divided guide groove is formed by laser processing. In the step of forming the first divided guide groove,
6. The method of manufacturing a nitride semiconductor laser element according to claim 1, wherein the first divided guide groove is formed by dry etching. In the step of forming the first divided guide groove,
The nitride semiconductor according to any one of claims 1 to 7, wherein the point-like portion of the first divided guide groove is formed at a location excluding an upper portion of the optical waveguide constituting the resonator. A method for manufacturing a laser element. Forming a plurality of optical waveguides arranged adjacent to each other in the first direction with respect to the nitride semiconductor layer;
In the step of forming the first divided guide groove,
The point-like portions of the first divided guide grooves are formed such that the distance between the point-like portions adjacent to each other in the first direction is equal to or less than the distance between the optical waveguides adjacent to each other in the first direction. A method for manufacturing a nitride semiconductor laser device according to claim 8. Forming a second divided guide groove along the second direction on the nitride semiconductor layer;
The method for manufacturing a nitride semiconductor laser device according to claim 1, further comprising a step of dividing the wafer substrate according to the second division guide groove. A nitride semiconductor laser element in which a nitride semiconductor layer including a light emitting layer having a resonator end face extending in a first direction formed by cleavage is laminated on a nitride semiconductor substrate,
A recess having different widths in the second direction perpendicular to the first direction is formed on a part of the side extending in the first direction of the nitride semiconductor layer on one end side and the other end side in the first direction. A nitride semiconductor laser device, wherein: A wafer substrate in which a nitride semiconductor layer including a light emitting layer is laminated on a nitride semiconductor substrate,
Formed on the nitride semiconductor layer of the wafer substrate is a first divided guide groove including a plurality of dot-like portions discretely arranged along a first direction in which a surface that becomes a resonator end surface extends after cleavage. And
The plurality of point-like portions each have a shape in which the front end side is narrower than the rear end side with respect to the width in the second direction orthogonal to the first direction, and the tip side of the point-like portion is the point-like portion. A wafer substrate, wherein the wafer substrate is disposed opposite to the rear end side of the other point-like portion adjacent to the substrate.

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