JP2009004524A - Nitride-based semiconductor laser element and manufacturing method of nitride-based semiconductor laser element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a nitride-based semiconductor laser element configured to have a ridge portion not damaged when a wafer is cleaved; and a method of manufacturing the nitride-based semiconductor laser element. <P>SOLUTION: The nitride-based semiconductor laser element is manufactured by cleaving and dividing a wafer 1 having a pad electrode 12 of height d<SB>m</SB>formed on the ridge portion 10 and a protection portion 11 of height d<SB>p</SB>. Further, the height d<SB>p</SB>of the protection portion 11 is larger than the height d<SB>m</SB>of the pad electrode 12, so that even when the wafer 1 is cleaved by applying a load thereto, for example, by pressing a blade against an (n)-side electrode 13 of the wafer 1, the protection portion 11 supports the wafer 1, thereby preventing the ridge portion 10 from being broken. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a nitride semiconductor laser element and a laser element, and more particularly, to a nitride semiconductor laser element manufactured by stacking a nitride semiconductor on a nitride semiconductor substrate and a method for manufacturing the same. About.

  Nitride-based semiconductors (eg, AlN, GaN, InN, AlGaN, InGaN, etc.), which are so-called III-V semiconductors composed of Group III elements and Group V elements, emit blue or blue-violet light from their band structures. Expected to be used as a light-emitting element, it has already been used for light-emitting diodes and laser elements.

  In addition, since a high-quality nitride-based semiconductor substrate has not been obtained so far, a nitride-based semiconductor element has been manufactured using a heterogeneous substrate such as a sapphire substrate. However, a wafer obtained by growing a nitride-based semiconductor on a dissimilar substrate such as a sapphire substrate has a different cleaved surface due to the difference in crystal structure between the substrate and the nitride semiconductor layer formed on the substrate. It has been difficult to cleave from wafer to bar to form the vessel end face.

In recent years, a high-quality gallium nitride substrate having the same cleavage plane as that of the nitride-based semiconductor layer can be obtained in response to this problem. By manufacturing a wafer using this substrate, the substrate can be easily cleaved. It became possible to do. In order to efficiently inject current, a nitride semiconductor laser element is usually provided with a ridge portion (see Patent Document 1).
JP 2006-229171 A

  However, when manufacturing a nitride semiconductor laser device having a ridge portion as described in Patent Document 1, it is necessary to cleave with a load such as pressing a blade against the wafer from the substrate side. Occasionally, the protruding ridge portion may come into contact with the work table or the like and be pressed to damage the ridge portion. A serious problem is that the yield of nitride semiconductor laser elements is reduced or the characteristics are deteriorated due to damage to the ridge portion.

  On the other hand, if the electrode is formed so as to cover the entire ridge portion, the electrode can prevent the ridge portion from coming into contact with the work table or the like and being damaged. However, in this configuration, the electrode formed on the ridge portion is pressed during cleaving to be plastically deformed and go around to the resonator end face of the bar obtained by cleaving, thereby increasing the possibility of contaminating the resonator end face.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a nitride semiconductor laser element having a configuration that does not damage a ridge portion when cleaving, and a method for manufacturing the nitride semiconductor laser element.

  In order to achieve the above object, a method for producing a nitride-based semiconductor laser device according to the present invention includes a direction extending in a predetermined direction on a first main surface of a substrate and a direction substantially perpendicular to the first main surface of the substrate. A first step of forming a laminated structure having a plurality of projecting portions projecting on the surface, and after the first step, a layer made of an insulator is laminated on the laminated structure and formed on a part of the projecting portions. A ridge portion is formed by removing the insulator, and a second step in which the insulator formed on another protruding portion is a protective portion, and after the second step, the ridge portion is formed on the ridge portion. A first electrode that does not exceed the height at which the protective portion protrudes along a predetermined direction is intermittently formed, and a second main surface that is the surface opposite to the first main surface of the substrate is secondly A third step of forming an electrode to obtain a wafer, and after the third step, Loads into the second electrode side of the wafer divided the wafer, characterized by comprising a fourth step of obtaining a chip, a.

  Further, in the method for manufacturing a nitride semiconductor laser device having the above-described configuration, the second step forms the protective portion intermittently along a direction substantially parallel to the predetermined direction of the ridge portion. It does not matter as being.

  In the method for manufacturing a nitride-based semiconductor laser device having the above structure, the fourth step includes a fifth step of forming a groove in a portion where the protective portion is not formed, and the groove after the fifth step. And a sixth step of dividing the wafer along the line.

  In the method for manufacturing a nitride-based semiconductor laser device having the above-described configuration, the substrate may be a gallium nitride substrate, and the insulator may be silicon dioxide.

  The nitride-based semiconductor laser device of the present invention includes a ridge portion formed on the first main surface of the substrate, extending in a predetermined direction and protruding in a direction substantially perpendicular to the first main surface of the substrate. A laminated structure; a first electrode formed intermittently on the ridge portion along the predetermined direction; and formed on the laminated structure and in a direction substantially perpendicular to the first main surface of the substrate. And a nitride-based semiconductor chip that includes a protective portion that protrudes and has a height higher than that of the first electrode.

  In the nitride semiconductor laser element having the above-described configuration, the insulator layer formed around the ridge portion may be made of the same material as the insulator forming the protective portion.

  According to the method for producing a nitride semiconductor laser device of the present invention, when the wafer is divided to obtain a bar or a chip, the protective portion is not Therefore, it is possible to prevent the first electrode from being plastically deformed or the ridge portion where the first electrode is not formed from being damaged. Therefore, the characteristics and yield of the nitride semiconductor laser element can be improved.

Hereinafter, a method for producing a nitride-based semiconductor laser device according to the present invention will be described with reference to FIGS. First, a series of nitride semiconductor laser device fabrication methods will be described with reference to FIGS. 1 to 6, and then another embodiment of the present invention will be described with reference to FIGS. 7 to 9.
<< Method for Fabricating Nitride Semiconductor Laser Device >>
<Wafer fabrication method>
First, an example of a wafer manufacturing method will be described with reference to the schematic views of the wafer in FIGS. FIG. 1A is a schematic plan view of a wafer, and FIG. 1B is a schematic cross-sectional view showing the AA cross section of FIG. 1A and 1B also show the crystal orientation of the substrate. 1 and the subsequent drawings also show the crystal orientation of the substrate in the same manner, and the configuration of the wafer, the bar, etc. will be described using this orientation.

  According to the wafer manufacturing method of this example, by laminating various layers on the substrate 2, as shown in FIGS. 1 (a) and 1 (b), the direction substantially parallel to the <1-100> direction of the substrate. A wafer 1 having a configuration in which a plurality of extended current passage portions (ridge portions 10) are aligned in the <11-20> direction is manufactured. Here, the pad electrode 12 is aligned in a direction along the ridge portion 10 and in a direction substantially perpendicular to the ridge portion 10. Further, one pad electrode 12 has one element structure, and a plurality of chips can be obtained by dividing the wafer 1 into pad electrodes 12 as will be described later.

  Further, in the wafer manufacturing method of this example, the protection portions 11 extending in the <1-100> direction, which is a direction substantially parallel to the ridge portion 10, are formed on both sides of each ridge portion 10. Therefore, two protection portions 11 are provided between the adjacent ridge portions 10.

Further, as shown in FIG. 1B, the protection portion 11 protrudes in the <0001> direction like the ridge portion 10, and the height d _p at which the protection portion 11 protrudes is provided on the ridge portion 10. pad electrode 12 is equal to or greater than the height d _m that protrudes to be. Further, in other words, the pad electrode 12 has a height d _m that does not exceed the height d _p of the protection portion 11.

  Next, an example of a wafer manufacturing method will be described with reference to FIGS. 2 to 4 are schematic cross-sectional views showing the same cross section as that in FIG. 1, and FIGS. 2 and 4 show a wafer manufacturing process. FIG. 3 is a schematic cross-sectional view showing an enlarged active layer.

  As shown in FIG. 2 (a), an n-type cladding layer 3 made of n-type AlGaN is first formed on the {0001} plane of an n-type GaN substrate 2 having a thickness of about 400 μm, and this n An active layer 4 is formed on the mold cladding layer 3. At this time, as shown in FIG. 3, the active layer 4 is composed of a plurality of alternating layers of a well layer 4a made of undoped InGaN having a thickness of about 3.2 nm and a barrier layer 4b made of undoped InGaN having a thickness of about 20 nm. A multiple quantum well structure is formed by stacking. In the example of FIG. 3, a case where three well layers 4a and four barrier layers 4b are stacked is shown.

  Further, an optical guide layer 5 made of undoped InGaN having a thickness of about 50 nm is formed on the active layer 4 having the multiple quantum well structure, and a thickness of about 5 nm made of undoped AlGaN is formed on the optical guide layer 5. A 20 nm cap layer 6 is formed. FIG. 2A shows a state in which the cap layer 6 is laminated on the substrate 2.

Then, a p-type cladding layer 7 made of p-type AlGaN and having a thickness of about 400 nm is formed on the cap layer 6 shown in FIG. Then, a contact layer 8 made of undoped InGaN and having a thickness of about 3 nm is formed on the p-type cladding layer 7. A p-side ohmic electrode 9 composed of a Pt layer having a thickness of about 1 nm and a Pd layer having a thickness of about 10 nm is formed on the contact layer 8, and a thickness of about 240 nm is formed on the p-side ohmic electrode 9. The SiO ₂ layer 15 is formed. In this way, each layer is formed to obtain a structure as shown in FIG.

Next, in order to form the ridge portion 10 and the protection portion 11, the stacked structure shown in FIG. At this time, a striped photoresist (not shown) having a width of about 1.5 μm and extending in the <1-100> direction of the substrate is formed on a portion where the ridge portion 10 and the protection portion 11 are to be formed. Then, etching by the RIE method is performed using a CF ₄ gas. Then, only the SiO ₂ layer 15 and the ohmic electrode 9 of the part forming the photoresist remains, SiO ₂ layer 15 and the ohmic electrode 9 of the portion not forming a photoresist is removed.

Also, the photoresist is removed here, and etching is performed by RIE using a chlorine-based gas such as Cl ₂ or SiCl ₄ . At this time, the contact layer 8 and the p-type cladding layer 7 where the SiO ₂ layer 15 is not present are etched using the SiO ₂ layer 15 as a mask. Then, when the p-type cladding layer 7 remains in a state where about 80 nm remains, the etching is stopped and the SiO ₂ layer 15 is removed. Then, as shown in FIG. 4A, a part of the p-type cladding layer 7 protrudes, and a contact layer 8 and an ohmic electrode 9 are sequentially formed on the protruding part of the p-type cladding layer 7. 10 and a structure including a plurality of protrusions serving as a base of the protection part 11 is obtained.

Next, an insulator layer made of, for example, SiO ₂ having a thickness of 2.4 μm is formed on the structure shown in FIG. Then, a photoresist 16 is formed on the insulator layer formed in a portion other than the portion that becomes the basis of the ridge portion 10 to obtain a structure as shown in FIG. This insulator layer functions as a current blocking layer 14 for preventing the current from spreading and flowing from the ridge portion 10 and as a protection portion 11 for protecting the ridge portion 10 when the wafer is cleaved into a bar. In the following, it is assumed that SiO ₂ is used for this insulator layer.

The structure shown in FIG. 4B is etched by the RIE method using a CF ₄ gas, and the insulator layer formed on the ridge portion 10 is removed. Then, the structure as shown in FIG. 4C is obtained by removing the photoresist 16. If the insulator layer between the protection part 11 and the ridge part 10 is deposited too thickly, a photoresist is formed on the ridge part 10 and the protection part 11, and the ridge part 10 and the protection part 11 are formed. The insulator layer between the two may be etched. Further, an etchant such as buffered hydrofluoric acid may be used for removing the insulator layer.

  Then, a pad electrode 12 made of Au and having a thickness of 2.2 μm is formed so as to cover the upper portion of the ridge portion 10 surrounded by the current blocking layer 14 having the structure shown in FIG. A plurality are formed on the top. At this time, as described above, if the pad electrode 12 is formed so as to cover the entire ridge portion 10, the pad electrode 12 wraps around the end face of the resonator and is contaminated when cleaving from the wafer to the bar. There is a risk that. For this reason, the pad electrode 12 is intermittently formed on the ridge portion 10, and cleavage as described later is performed on the portion where the pad electrode 12 is not formed.

  Further, the substrate 2 is subjected to physical polishing such as lapping and polishing on the surface opposite to the surface of the substrate 2 on which the laminated structure as described above is formed with respect to the structure shown in FIG. The thickness of the substrate 2 is reduced to 100 μm and the polished surface is flattened. Then, the n-side electrode 13 is formed on the polished surface of the substrate 2 to obtain the wafer 1 as shown in FIG.

In the wafer manufacturing method described above, the MOCVD (Metal Organic Chemical Deposition) method may be used for forming each nitride-based semiconductor layer, and the MBE (Molecular Beam Epitaxy) method or the HVPE (Hydride Vapor Papour) method. (Epitaxial) method and other methods may be used. In addition, a formation method such as sputtering or vapor deposition may be used for forming the electrode, and as the vapor deposition, electron beam vapor deposition may be used, or resistance heating vapor deposition may be used. In addition, a method such as PECVD (Plasma Enhanced Chemical Vapor Deposition) or sputtering may be used to form the SiO ₂ layer.

  Further, in FIG. 1A, the wafer 1 is shown as a square shape for the sake of simplicity, but a laminated structure is formed on a substantially circular substrate including an orientation flat surface and a notch for confirming the crystal orientation. However, a wafer may be produced.

Further, in FIG. 4A, the SiO ₂ layer 15 is removed from all the protruding portions, that is, all the protruding portions that are the basis of the ridge portion 10 and the protective portion 11. In the protruding portion, the SiO ₂ layer 15 may not be removed.

  In the example of the method for manufacturing the wafer 1, a laminated structure is formed on the {0001} plane of the substrate. However, it is formed on the {11-20} plane or the {1-100} plane of the substrate. It doesn't matter. In addition, when the surface of the substrate 2 forming the laminated structure is changed in this way, the direction in which the ridge portion 10 and the protection portion 11 are formed and the cleavage direction are appropriately changed.

Further, the wafer manufacturing method described above is an example, and may be changed as appropriate, for example, by changing the thickness of each layer, changing the width of the ridge portion 10, or changing the shape of the pad electrode 12. Absent. However, the thickness d _p of the protection unit 11, the relationship of d _p ≧ d _m for the thickness d _m of the pad electrode 12 is preferably maintained.

<Wafer cutting>
Next, the obtained wafer 1 is cleaved and divided to obtain chips, and an example of a method for manufacturing a nitride-based semiconductor laser device using the chips will be described with reference to FIGS. FIG. 5 is a schematic plan view showing a wafer, a bar, and a chip, and FIGS. 5A and 5B show a surface opposite to the surface of the wafer shown in FIG. . FIG. 5C shows the surface on the same side as the wafer of FIG. 1A, that is, the surface opposite to the surface of the wafer and bar shown in FIGS. 5A and 5B. is there. FIG. 6 is a schematic perspective view of the nitride semiconductor laser element. Hereinafter, a case where a wafer obtained by an example of the above-described wafer manufacturing method is used will be described.

  First, as shown in FIGS. 5A and 5B, the bar 17 is obtained by cleaving the wafer 1 along the <11-20> direction of the substrate 2. At this time, as described above, cleavage is performed while avoiding the pad electrode 12. The obtained bar 17 has a structure in which the element structures are aligned in a row in the <11-20> direction with two end faces ({1-100} plane) obtained by cleaving as resonator end faces.

  At this time, cleavage is performed by applying a load such as pressing a blade against the wafer surface (the surface on which the n-side electrode 13 is formed) shown in FIG. Therefore, the surface of the work table or the like and the surface of the wafer 1 provided with the ridge portion 10, the protection portion 11, and the pad electrode 12 face each other.

  Then, the bar 17 shown in FIG. 5B is obtained by cleaving the wafer 1 as described above. At this time, since the protection part 11 protrudes from the pad electrode 12 provided on the ridge part 10, even if a load is applied to the wafer 1 from the n-side electrode 13 side and the wall is opened, the protection part 11 causes the wafer 1. Can be supported. Therefore, it is possible to prevent the ridge portion 10 from being damaged due to contact with the work table or the like, and in particular, it is also possible to prevent damage to the portion of the ridge portion 10 that is not covered with the easily damaged pad electrode 12. Become. Further, it is possible to prevent the pad electrode 12 from being plastically deformed and contaminating the resonator end face.

  Before performing this cleavage, a linear or broken line groove may be formed on the line to be cleaved so that the cleavage can be easily performed. In addition, this groove may be formed on the surface opposite to the surface shown in FIG. 5A where the pad electrode 12 and the protection portion 11 are formed.

Further, as the material of the protective portion 11, a hard insulator material that hardly causes plastic deformation such as SiO ₂ can be used. Therefore, the ridge portion 10 can be more reliably compared with a material such as a soft metal that is easily plastically deformed. Cleavage can be performed while preventing damage to the pad and plastic deformation of the pad electrode 12.

  Further, since these insulators do not need to be epitaxially grown and can be formed at high speed by sputtering or the like, the protective portion 11 can be easily manufactured. Further, since the temperature during film formation can be kept low, damage to the wafer 1 during film formation can be reduced. Furthermore, since it can be formed simultaneously with the buried layer 14, an increase in man-hours can be prevented.

Note that the resonator end face of the bar 17 obtained by cleaving the wafer 1 may be coated with, for example, SiO ₂ , TiO ₂ , or Al ₂ O ₃ . Further, the coating formed on one of the end faces is made up of a large number of layers of about 10 layers, and the reflectance is increased, and the coating formed on either of the end faces is made up of a small number of layers of about one layer. The reflectance may be lowered. These coatings have the effect of improving the light emission efficiency and the effect of preventing impurities from adhering to the resonator end face.

  Then, as shown in FIG. 5C, the chip 18 is obtained by dividing the obtained bar 17 along the <1-100> direction. At this time, one chip 18 includes one element structure, and a nitride-based semiconductor laser element 20 as shown in FIG. 6 is manufactured using this chip 18. Note that the bar 17 may be divided so that the protection part 11 is included in the chip 18, or the bar 17 may be divided so as not to include the protection part 11.

  Also, in the division from the bar 17 to the chip 18, as in the cleavage from the wafer 1 to the bar 17, a groove along the division direction is formed in the bar 17, and cleavage and division are performed along this groove. It does not matter. The groove may be a solid line or a broken line, and the groove may be formed when the wafer 1 or the bar 17 is in the state. Further, a groove may be formed on the surface of the wafer 1 or the bar 17 where the pad electrode 12 or the protection part 11 is formed, or a groove may be formed on the surface of the n-side electrode 13 formed. It doesn't matter.

  Further, as described above, when the groove is formed before cleaving the wafer 1 or dividing the bar 17, it is preferable to avoid the protective portion 11. Further, it is preferable that the protection unit 11 is not provided on the line for dividing the bar.

<Mount chip>
As shown in FIG. 6, the nitride-based semiconductor laser device 20 includes a submount 23 in which a chip 18 is electrically connected and fixed (mounted) by solder, a heat sink 22 connected to the submount 23, and a heat sink 22 A stem 21 connected to a certain surface, pins 24a and 24b passing through a surface of the stem 21 connected to the heat sink 22 and a surface opposite to the certain surface and insulated from the stem 21, and one pin 24a And a wire 25b that electrically connects the pad electrode 12 of the chip 18 and a wire 26b that electrically connects the other pin 24b and the submount 23.

  Further, although not shown for easy understanding of the configuration of the nitride-based semiconductor laser device 20, it is connected to the surface with the stem 21 to which the heat sink 22 is connected, the chip 18, the submount 23, the heat sink 22, The cap 24 which seals the part which protrudes from the surface with the stem 21 of the pins 24a and 24b, and the wires 25a and 25b.

  Then, current is supplied to the chip 18 through the two pins 24 a and 24 b to oscillate, and laser light is emitted from the chip 18. At this time, the cap is provided with a window made of a material transparent to the emitted laser beam, and the laser beam is emitted through the window.

The configuration of the nitride-based semiconductor laser device 20 shown in FIG. 6 is an example, and the configuration of the heat sink 22, the submount 23, the pins 24a and 24b, the wires 25a and 25b, the cap, and the like is another configuration. It doesn't matter.
<< Other Examples >>
In the above, a series of methods for manufacturing a nitride semiconductor laser element and an example of a nitride semiconductor laser element to be manufactured according to the present invention have been described. In the following, in addition to the nitride semiconductor laser element including the protection unit 11 described above, Examples will be described.

<First embodiment>
First, a first embodiment of the method for forming the protection part 11 according to the present invention will be described with reference to FIG. FIG. 7 is a plan view of the wafer shown on the same plane as FIG.

  In the wafer 1 shown in FIG. 1A, two protection portions 11 are provided on both sides of the ridge portion 10, and two protection portions 11 are provided between adjacent ridge portions 10. In the wafer 1a, every two ridges 10 are provided with a protective part 11. That is, the ridge portion 10 and the protection portion 11 are alternately arranged along the <11-20> direction.

  With this configuration, like the wafer 1 shown in FIG. 1A, when the wafer 1a is cleaved or when the bar is divided, the protection unit 11 comes into contact with the work table and supports the wafer 1a and the bar. It is possible to prevent the ridge portion 10 from being damaged due to contact with the work table or the like, and the pad electrode 12 from being plastically deformed. Further, since it is possible to reduce the number of protection portions 11 to be created, it becomes possible to easily cleave the wafer 1a that divides the protection portion 11 substantially vertically.

<Second embodiment>
Next, a second embodiment will be described with reference to FIG. FIG. 8 is a plan view of a wafer corresponding to FIG. 7 shown for the first embodiment. In the second embodiment, the distance between the protection portions 11 in the <11-20> direction is wider than that in the first embodiment, and the number of the protection portions 11 is further reduced. Specifically, every two ridges 10 are provided with a protective part 11.

  Even with this configuration, as in the first embodiment, when the wafer 1a is cleaved or when the bar is divided, the protection unit 11 can contact the work table and support the wafer 1a and the bar. It is possible to prevent the ridge portion 10 from being damaged due to contact with the work table or the like, and plastic deformation of the pad electrode 12. Furthermore, since it is possible to reduce the number of protection portions 11 created as compared with the first embodiment, it is possible to further easily cleave the wafer 1a that divides the protection portion 11 substantially vertically. .

  In the first embodiment, the protective portion 11 is formed every other ridge portion 10 in the wafer 1a, and the protective portion 11 is formed every two ridge portions 10 in the wafer 1b in the second embodiment. However, the protective portion 11 may be formed by every three or four ridge portions 10.

<Third embodiment>
Next, a third embodiment will be described with reference to FIG. FIGS. 9A and 9B are plan views of the wafer corresponding to FIG. 7 showing the first embodiment and FIG. 8 showing the second embodiment. The wafers 1c and 1d in the third embodiment are such that the protective portion 11 is intermittently formed along the <1-100> direction, and the wafer 1 shown in FIG. This is different from the wafer 1a in FIG. 7 in the example and the wafer 1b in FIG. 8 in the second embodiment.

  In the wafer 1c of FIG. 9A, the <11-20> direction is aligned as in FIG. That is, two protective portions 11 are formed between the adjacent ridge portions 10 and arranged. However, these protection parts 11a are intermittent with respect to the <1-100> direction, and the portion where the protection part 11a is interrupted and the space between the pad electrodes 12 in the <1-100> direction are < The protection part 11a and the pad electrode 12 are disposed along the 11-20> direction.

  Therefore, the wafer 1c can be cleaved with a straight line passing between the pad electrodes 12 and between the protective portions 11a. At this time, since the cleaving can be performed at a portion where the protection part 11a is interrupted, the cleaving can be easily performed even if the protection part 11a is formed. Furthermore, since a groove for cleaving can be formed in the interrupted portion of the protective portion 11a, this configuration can relax the limitation of the groove formed when the wafer 1c is cleaved.

  Similarly to the first and second embodiments, when the wafer 1c is cleaved or when the bar is divided, the protection unit 11a can contact the work table and support the wafer 1c and the bar. It is possible to prevent the portion 10 from being damaged due to contact with the work table or the like, and the pad electrode 12 from being plastically deformed.

  In addition, as shown in FIG.9 (b), you may reduce the number of the protection parts 11a. In the wafer 1d shown in FIG. 9B, as in the first embodiment, every two ridges 10 are provided with a protective part 11a along the <11-20> direction. . Further, the protective portion 11a may be formed by every two or three ridge portions 10 or the like.

  In addition, in order to obtain the configuration of the wafers 1c and 1d provided with the protection part 11a shown in FIGS. 9A and 9B, after the protection part 11 having no interruption is formed once, the interruption part is formed by etching. It doesn't matter. Specifically, if the photoresist 16 in FIG. 4B is not formed in a portion where the protective portion 11 is desired to be interrupted, the interrupted portion can be easily formed by etching.

  The present invention relates to a nitride-based semiconductor laser device and a manufacturing method thereof, and particularly to a semiconductor laser device manufactured by stacking a nitride-based semiconductor on a nitride-based semiconductor substrate and a manufacturing method thereof. It is preferable.

These are a schematic plan view and a cross-sectional view showing an example of a wafer. These are typical sectional drawings which show an example of the manufacturing method of a wafer. These are the typical sectional views shown about the active layer. These are typical sectional drawings which show an example of the manufacturing method of a wafer. These are the typical top views showing an example of a wafer, a bar, and a chip. FIG. 3 is a schematic perspective view showing an example of a nitride-based semiconductor laser device. These are the typical top views of the wafer in 1st Example. These are the typical top views of the wafer in the 2nd example. These are the typical top views of the wafer in 3rd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer 2, 2a Substrate 2b Stripe core 2c Other area 3 N-type cladding layer 4 Active layer 4a Well layer 4b Barrier layer 5 Optical guide layer 6 Cap layer 7 P-type cladding layer 8 Contact layer 9 P-side ohmic electrode 10 Ridge part 11 protection unit 12 the pad electrode 13 n-side electrode 14 current blocking layer 15 SiO ₂ layer 16 photoresist 17 bar 18 chips

Claims (5)

Forming a stacked structure including a plurality of protrusions extending in a predetermined direction and protruding in a direction substantially perpendicular to the first main surface of the substrate on the first main surface of the substrate; and
After the first step, a layer made of an insulator is stacked on the stacked structure, and the ridge portion is formed by removing the insulator formed on a part of the protrusions, and the other protrusions A second step using the insulator formed thereon as a protective part;
After the second step, the first electrode is intermittently formed on the ridge portion so as not to exceed the protruding height of the protection portion along the predetermined direction, and the first main surface of the substrate is formed. A third step of obtaining a wafer by forming a second electrode on the second main surface which is the opposite surface;
After the third step, a fourth step of obtaining a chip by applying a load to the second electrode side of the wafer and dividing the wafer,
A method for producing a nitride-based semiconductor laser device, comprising:   2. The nitride system according to claim 1, wherein the second step forms the protective part intermittently along a direction substantially parallel to the predetermined direction of the ridge part. 3. A method for manufacturing a semiconductor laser element. The fourth step includes a fifth step of forming a groove in a portion where the protective portion is not formed;
A method for producing a nitride-based semiconductor laser device according to claim 1, further comprising a sixth step of dividing the wafer along the groove after the fifth step. . A laminated structure including a ridge formed on the first main surface of the substrate and extending in a predetermined direction and protruding in a direction substantially perpendicular to the first main surface of the substrate;
A first electrode intermittently formed on the ridge portion along the predetermined direction;
A protective portion made of an insulator formed on the laminated structure, protruding in a direction substantially perpendicular to the first main surface of the substrate and having a height higher than the first electrode;
A nitride semiconductor laser device comprising: a nitride semiconductor chip comprising:   5. The nitride semiconductor laser element according to claim 4, wherein an insulator layer formed around the ridge portion is made of the same material as that of the insulator forming the protective portion.

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