JP2008060272A - Method for manufacturing semiconductor laser device, and semiconductor laser device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a plurality of semiconductor laser element parts having various lengths of resonator on an identical substrate. <P>SOLUTION: A method for manufacturing a semiconductor laser device comprises the steps of forming a first laminated structure by depositing an etching accelerator layer 113, a first n-type cladding layer 102, a first active layer 103, and a first p-type cladding layer 104 in a first element formation region on a semiconductor substrate 101; forming a second laser element part 121 having a reflecting mirror on both ends on a second element formation region by depositing and cleaving a second n-type cladding layer 108, a second active layer 109, and a second p-type cladding layer 110 in the second element formation region; forming a first laser element material part having the reflecting mirror on one side and an end surface on the other side in the first element formation region; removing an etching accelerator layer 113 from the end surface to the predetermined depth of the first laser element material part; removing the part of a first laminated structure on the region where the removed etching accelerator layer 113 resided by the cleavage; and forming a first laser element part 120 having the length in a resonance direction shorter than that of the second laser element part 121. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor laser device and a manufacturing method thereof. For example, optical disc devices such as DVD-RAM, DVD-R, DVD-RW, DVD + R, DVD + RW, CD-R, CD-RW, DVD-ROM, CD-ROM, DVD-Video, CD-DA, VCD, or optical The present invention relates to a semiconductor laser device used for information processing, optical communication, optical measurement, and the like, and a manufacturing method thereof.

  An AlGaInP red laser having a wavelength of 650 nm is used as a read / write pickup light source for DVD-RAM and the like. On the other hand, an AlGaAs infrared laser having a wavelength of 780 nm band is used as a pickup light source for reading and writing such as CD-R. In order to support both of these disks, both a red laser and an infrared laser are required for one drive. Therefore, a drive provided with two optical integrated units for DVD and CD is generally popular.

  However, due to recent demands for miniaturization, cost reduction, and simplification of the optical system assembly process, a dual wavelength laser in which two lasers are integrated on the same substrate has been put into practical use so that it can be handled by one optical integrated unit. (See, for example, Patent Document 1).

  FIG. 7A shows a perspective view of the two-wavelength semiconductor laser device described in Patent Document 1. FIG. FIG.7 (b) has shown the AA arrow sectional drawing of Fig.7 (a).

  This two-wavelength semiconductor laser device includes an infrared laser element unit 220 and a red laser element unit 221 in different regions on the same GaAs substrate 201.

  The infrared laser element unit 220 includes an infrared laser n-type cladding layer 202, an infrared laser active layer 203, an infrared laser p-type cladding layer 204, a current blocking layer 205, a contact layer 206, an infrared laser p-side electrode 207, And an n-side electrode 212 common to the red laser element portion 221. The red laser element portion 221 includes a red laser n-type cladding layer 208, a red laser active layer 209, a red laser p-type cladding layer 210, a current blocking layer 205, a contact layer 206, a red laser p-side electrode 211, and an infrared ray. The n-side electrode 212 is used in common with the laser element unit 220.

  An AlGaAs-based material is used for the infrared laser active layer 203 constituting the infrared laser element portion 220, and an AlGaInP-based material is used for the red laser active layer 209 constituting the red laser element portion 221. Is used.

In this way, an optical pickup comprising a 650 nm band AlGaInP red laser and a 780 nm band AlGaAs infrared laser monolithically integrated on one GaAs substrate, and both DVD / CD lasers on one optical integrated unit. Is realized.
JP 2000-11417 A

  However, in the semiconductor laser device having a configuration in which a plurality of laser element portions are provided on the same substrate as described in Patent Document 1, the resonator length cannot be optimized for each laser element portion. This problem will be described below.

  In the manufacturing process of a two-wavelength semiconductor laser device having a configuration in which a plurality of laser element portions 220 and 221 are provided on the same substrate 201 as shown in FIG. A resonator is formed by cleaving, as in a conventional laser device having only one configuration. In that case, since the plurality of laser element portions 220 and 221 are provided on the common substrate 201, the plurality of laser element portions 220 and 221 are simultaneously cleaved on the same surface. Since the resonator length of each laser element portion is determined by the cleavage positions at both ends, the resonator lengths of the red laser element portion 221 and the infrared laser element portion 220 are necessarily the same.

  The resonator length is one of the parameters that influence the laser characteristics such as maximum light output, oscillation threshold current, and efficiency. In the case of a two-wavelength laser device as shown in FIG. 7, the red laser element unit 221 and the infrared laser element are used. There is a restriction that the resonator length cannot be optimized independently of the unit 220.

  8 (a) and 8 (b) show a case where the resonator length is 1000 μm and 1800 μm in the two-wavelength semiconductor laser device in which the red laser element portion and the infrared laser element portion are monolithically integrated as shown in FIG. Each current-light characteristic is shown.

  As can be seen from FIG. 8A, when the resonator length is 1000 μm, the red laser element portion cannot obtain a desired light output due to thermal saturation in the vicinity of 360 mW. That is, in order to obtain a light output of 400 mW or more, it is necessary to further increase the resonator length of the red laser element portion.

  When the resonator length is set to 1800 μm as shown in FIG. 8B, the infrared laser element portion and the red laser element portion both obtain a desired light output. It can be seen that the operating current of the part increases as the active layer volume increases compared to the case where the resonator length is 1000 μm. Due to this increase in power consumption, the operable time when mounted on a battery-driven portable device is disadvantageous compared to a single laser.

  Thus, in the two-wavelength semiconductor laser device as shown in FIG. 7, when a high output of 400 mW class is to be realized in the red laser element section, the resonator length is required to be at least 1800 μm or more. When the resonator length of the laser diode is 1800 μm or more, the operating current is greatly increased as compared with a conventional laser device having a single laser element, and there is an adverse effect such as an increase in power consumption and promotion of element deterioration due to heat generation. May affect. Under such circumstances, it has been difficult to increase the output in the two-wavelength semiconductor laser device configured as shown in FIG.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described conventional problems, and to provide a semiconductor laser device having a plurality of semiconductor laser element portions each having an optimum resonator length on the same substrate and a method for manufacturing the same. To do.

In order to solve the above-described problem, the first aspect of the present invention provides:
A first first-conductivity-type cladding layer, a first active layer, and a first second-conductivity-type cladding layer are sequentially formed on the etching promoting layer formed in the first laser element formation region on the semiconductor substrate. A first laminated structure forming step of depositing to form a first laminated structure;
A second stacked structure is formed by sequentially depositing a second first-conductivity-type cladding layer, a second active layer, and a second second-conductivity-type cladding layer in a second laser element formation region on the semiconductor substrate. A second laminated structure forming step of forming
By cleaving, a second semiconductor laser element portion having reflecting mirrors on both end faces is formed on the second laser element forming area, and a reflecting mirror, etc. on one side is formed on the first laser element forming area. A first cleaving step of forming a first semiconductor laser element portion material portion having an end face on the surface;
An acceleration layer etching step of removing the etching acceleration layer by etching at a predetermined depth from the end face of the first semiconductor laser element portion material portion;
The portion of the first laminated structure on the region where the etching acceleration layer removed by the acceleration layer etching process was removed is removed by cleavage, and the resonance direction is parallel to the second semiconductor laser element portion. And a second cleaving step of forming a first semiconductor laser element portion having a different wavelength and a resonance direction length shorter than that of the second semiconductor laser element portion. It is.

The second aspect of the present invention
In the first laminated structure forming step, the etching promoting layer, the first first conductivity type cladding layer, the first active layer, and the first second conductivity type cladding layer are formed on the semiconductor substrate. After sequentially depositing, the etching promoting layer, the first first conductivity type cladding layer, the first active layer, deposited on a region other than the first laser element formation region on the semiconductor substrate, And removing the first second conductivity type cladding layer to form the first laminated structure,
In the second stacked structure forming step, the second first-conductivity-type cladding layer, the second active layer, and the second active layer are formed on the semiconductor substrate including the first stacked structure formed in the first stacked structure forming step. And a second first-conductivity-type cladding layer deposited on a region other than the second laser element formation region on the semiconductor substrate after sequentially depositing a layer and the second second-conductivity-type cladding layer. In the method of manufacturing a semiconductor laser device according to the first aspect of the present invention, the second stacked structure is formed by removing a layer, the second active layer, and the second second-conductivity-type cladding layer. is there.

The third aspect of the present invention
The etching acceleration layer has a higher etching rate than both the semiconductor substrate and the first first conductivity type cladding layer,
In the accelerating layer etching step, a portion excluding a portion of the etching accelerating layer to be removed and a portion of the semiconductor substrate adjacent thereto and a portion of the first first conductivity type cladding layer is masked. 1 is a method of manufacturing a semiconductor laser device according to the first aspect of the present invention.

The fourth aspect of the present invention is
The etching promotion layer is a method of manufacturing a semiconductor laser device according to a third aspect of the present invention, wherein the Al composition ratio is larger than both the semiconductor substrate and the first first-conductivity-type cladding layer.

The fifth aspect of the present invention provides
A semiconductor substrate;
A first semiconductor laser element section having a first first-conductivity-type cladding layer, a first active layer, and a first second-conductivity-type cladding layer, which are sequentially stacked on the semiconductor substrate;
The first semiconductor laser element unit includes a second first-conductivity-type cladding layer, a second active layer, and a second second-conductivity-type cladding layer, which are sequentially stacked on the semiconductor substrate. A semiconductor laser device comprising: a second semiconductor laser element portion having a parallel resonance direction, different wavelengths of emitted laser light, and a longer resonance direction length than the first semiconductor laser element portion.

The sixth aspect of the present invention provides
The first semiconductor laser element portion has an etching rate between the semiconductor substrate and the first first conductivity type cladding layer, which is higher than that of either the semiconductor substrate or the first first conductivity type cladding layer. The semiconductor laser device according to the fifth aspect of the present invention has a fast etching promoting layer.

  According to the present invention, it is possible to provide a semiconductor laser device including a plurality of semiconductor laser element portions each having an optimum resonator length on the same substrate, and a manufacturing method thereof.

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

  FIG. 1A is a perspective view of a dual-wavelength high-power laser apparatus having a light output of 400 mW class according to an embodiment of the present invention. FIG. 1B shows a cross-sectional view taken along the line AA perpendicular to the resonance direction of FIG.

  The two-wavelength high-power laser device of the present embodiment includes an infrared laser element unit 120 that emits an AlGaAs-based infrared laser beam of 780 nm band and an AlGaInP-based red laser of 650 nm band on the same n-type GaAs substrate 101. A red laser element portion 121 that emits light is provided.

  The infrared laser element unit 120 includes a side etching promoting layer 113, an infrared laser n-type cladding layer 102, an infrared laser active layer 103, an infrared laser p-type cladding layer 104, a current blocking layer 105, a contact layer 106, an infrared ray. It is composed of a laser p-side electrode 107 and an n-side electrode 112 common to the red laser element part 121. Here, the side etching promoting layer 113 is made of a material having a larger Al composition ratio than both the substrate 101 and the infrared laser n-type cladding layer 102.

  The red laser element 121 includes a red laser n-type cladding layer 108, a red laser active layer 109, a red laser p-type cladding layer 110, a current blocking layer 105, a contact layer 106, a red laser p-side electrode 111, and an infrared ray. The n-side electrode 112 common to the laser element unit 120 is used.

The dual-wavelength high-power laser device of this embodiment is an example of the semiconductor laser device of the present invention, and the infrared laser element unit 120 and the red laser element unit 121 are respectively the first semiconductor laser device of the present invention. Part and an example of the second semiconductor laser element part.

  Further, the side etching promoting layer 113, the infrared laser n-type cladding layer 102, the infrared laser active layer 103, and the infrared laser p-type cladding layer 104 are the etching promoting layer and the first first conductivity type of the present invention, respectively. This is an example of a cladding layer, a first active layer, and a first second conductivity type cladding layer. Also, the red laser n-type cladding layer 108, the red laser active layer 109, and the red laser p-type cladding layer 110 are respectively the second first-conduction-type cladding layer, the second active layer, and the second second-layer of the present invention. This is an example of a two-conduction cladding layer.

  Table 1 shows the material, conductivity type, film thickness, and carrier concentration of each layer of the infrared laser element portion 120 and the red laser element portion 121.

  An AlGaAs-based material is used for the infrared laser active layer 103 of the infrared laser element unit 120, whereas an AlGaInP-based material is used for the red laser active layer 109 of the red laser element unit 121.

  Each of the infrared laser p-type cladding layer 104 and the red laser p-type cladding layer 110 has a striped mesa structure, and the width of these mesas is 1 μm at the top and 3 μm at the bottom.

  The infrared laser element unit 120 and the red laser element unit 121 have different resonator lengths of 1000 μm and 1800 μm, respectively, and are arranged so that their resonance directions are parallel to each other. In the present invention, “the resonance directions of the two semiconductor element portions are parallel” is preferably parallel within a range of ± 1 degree or less.

  The feature of the two-wavelength high-power laser device of the present embodiment is that the resonator lengths of the infrared laser element unit 120 and the red laser element unit 121 are different.

  FIG. 6 shows current-light characteristics of the infrared laser element unit 120 and the red laser element unit 121 of the dual-wavelength high-power laser device of the present embodiment.

  Compared with the current-optical characteristics of the conventional two-wavelength semiconductor laser device of FIG. 8, in the two-wavelength high-power laser device of the present embodiment, the optical output of the red laser achieves 400 mW, while operating current of the infrared laser. It can be seen that the value is comparable to an element having a resonator length of 1000 μm.

  Next, a method for manufacturing the dual-wavelength high-power laser device according to the present embodiment will be described with reference to FIGS.

  2 to 5 are schematic structural diagrams showing manufacturing steps of the dual-wavelength high-power laser device of the present embodiment. Each is shown by a cross-sectional view or a perspective view along arrow AA in FIG.

  First, as shown in FIG. 2A, a side etching promoting layer 113, an infrared laser n-type cladding layer 102, an infrared laser active layer 103, and an infrared laser p-type cladding layer 104 are formed on an n-type GaAs substrate 101. Are sequentially stacked.

  Next, as shown in FIG. 2B, in the region other than the region where the infrared laser element portion 120 is formed (hereinafter referred to as an infrared laser element formation region) on the substrate 101, the side etching promoting layer 113, The infrared laser n-type cladding layer 102, the infrared laser active layer 103, and the infrared laser p-type cladding layer 104 are removed.

  The infrared laser element formation region is an example of the first laser element formation region of the present invention, and the laminated structure formed on the infrared laser element formation region of FIG. This is an example of the laminated structure. 2A and 2B corresponds to an example of the first laminated structure forming step of the present invention.

  Next, as shown in FIG. 2C, a red laser n-type cladding layer 108, a red laser active layer 109, and a red laser p-type cladding layer 110 are formed on the substrate 101 including the infrared laser element formation region. Laminate sequentially.

  Next, as shown in FIG. 3D, the red laser n-type cladding layer 108 and the red laser active layer 109 are formed in a region other than a region where the red laser element portion 121 is formed (hereinafter referred to as a red laser element formation region). The red laser p-type cladding layer 110 is removed.

  Note that the red laser element formation region is an example of the second laser element formation region of the present invention, and the stacked structure formed on the red laser element formation region of FIG. 3D is the second stack of the present invention. This is an example of the structure. Moreover, the process shown in FIG. 2C and FIG. 3D corresponds to an example of the second laminated structure forming process of the present invention.

  Then, as shown in FIG. 3E, a part of the infrared laser p-type clad layer 104 and the red laser p-type clad layer 110 is etched to form a striped mesa structure.

  Next, as shown in FIG. 3 (f), after selective regrowth of the current blocking layer 105 on the portion other than the upper part of the mesa structure, as shown in FIG. 4 (g), from above the substrate 101, The contact layer 106 is regrown.

  Next, as shown in FIG. 4 (h), the vicinity of the boundary between the infrared laser element formation region and the red laser element formation region is etched to the substrate 101 to perform element separation, and then the infrared laser element formation region and the red laser element formation region An infrared laser p-side electrode 107 and a red laser p-side electrode 111 are formed on each contact layer 106 in the laser element formation region. Further, an n-side electrode 112 is formed on the back surface of the substrate 101. FIG. 4H also shows a perspective view after the n-side electrode 112 is formed.

  Subsequently, both end faces are formed by cleavage so that the resonator length is 1800 μm in each of the laminated structure of the portion that becomes the infrared laser element portion 120 and the laminated structure of the portion that becomes the red laser element portion 121. By the cleavage at this time, reflecting mirrors are formed on both end surfaces of the laminated structure of the portion that becomes the red laser element portion 121, and the red laser element portion 121 is completed. In addition, due to the cleavage at this time, a reflecting mirror is also formed on the end surface on the light emission side (the end surface on the left side of FIG. 5I) of the laminated structure of the portion that becomes the infrared laser element portion 120.

  The cleavage process here is an example of the first cleavage process of the present invention. Further, the laminated structure of the portion that becomes the red laser element portion 121 having both end faces formed by cleavage is an example of the first semiconductor laser element portion material portion of the present invention.

  Then, as shown in FIG. 5 (i), the side etching promoting layer 113 on the opposite side of the light emitting surface and the n-type GaAs substrate 101 adjacent thereto in the laminated structure of the portion that becomes the infrared laser element portion 120 and the infrared The other region is masked by polyimide coating so that only the region including a part of the laser n-type cladding layer 102 is exposed. The portions shown in gray in FIGS. 5 (i) and (j) indicate the portions masked with polyimide.

Then, as shown in FIG. 5 (j), HF: H 2 O 2 = 1: By Hitachaku 10 solution, the opposite side of the light exit surface of the laminated structure of the portion to be the infrared laser element portion 120 The side etching promoting layer 113 is etched by about 900 μm from the side toward the resonator. At this time, the n-type GaAs substrate 101 and the infrared laser n-type cladding layer 102 are also exposed to the solution. However, since the etching rate (etching rate) of the side etching promoting layer 113 having a higher Al composition is slower, side etching is performed. Only the facilitating layer 113 is selectively etched.

  In addition, the process which etches the side etching acceleration | stimulation layer 113 of FIG.5 (j) corresponds to an example of the acceleration | stimulation layer etching process of this invention. Further, the distance of 900 μm etched from the opposite side of the light emitting surface at this time corresponds to an example of the predetermined depth of etching according to the present invention.

  Then, as shown in FIG. 5 (k), after removing the polyimide, microcleaving is performed from the upper part of the layered structure of the portion that becomes the infrared laser element portion 120 so that the resonator length becomes 1000 μm. By this micro-cleavage cleavage, a reflecting mirror is formed on the opposite side of the light emitting surface of the laminated structure of the portion that becomes the infrared laser element unit 120, and the infrared laser element unit 120 having a resonator length of 1000 μm is completed.

  Micro-cleaving is a technique for cleaving a part of the stack without dividing the substrate. This is a method of removing a layer formed under a laminated structure to be cleaved by etching, and cleaving the laminated structure part above the removed part, and is disclosed in Japanese Patent Laid-Open No. 5-243683.

  In addition, the cleavage process by microcleave in FIG.5 (k) corresponds to an example of the 2nd cleavage process of this invention.

  Thereafter, chip separation and packaging are performed to complete the dual-wavelength high-power laser device.

  The manufacturing method of the semiconductor laser device of the present invention is cleaved at different positions on the opposite sides of the light emitting ends of red and infrared by utilizing micro cleaving technology, so it is optimal for each semiconductor laser element part. It is possible to set a long resonator length and improve the laser characteristics of each.

  Since the semiconductor laser device of the present invention can independently control the resonator lengths of a plurality of semiconductor laser element portions as described above, the degree of freedom in structural design of each semiconductor laser element portion is increased, and laser characteristics are improved. It becomes possible to raise.

  Since the semiconductor laser device and the manufacturing method thereof according to the present invention include a plurality of semiconductor laser element portions each having an optimum resonator length on the same substrate, a light source for picking up an optical disc centered on DVD / CD, It is useful as a semiconductor laser device used for a light source for optical information processing, optical communication, optical measurement, and the like, and a manufacturing method thereof.

(A) Perspective view of dual-wavelength high-power laser device in embodiment of the present invention, (b) AA sectional view of dual-wavelength high-power laser device in embodiment of the present invention (A)-(c) Schematic structure figure which shows the manufacturing process of the dual wavelength high output laser apparatus in embodiment of this invention (D)-(f) Schematic structure figure which shows the manufacturing process of the dual wavelength high output laser apparatus in embodiment of this invention (G), (h) Schematic structure diagram showing the manufacturing process of the dual-wavelength high-power laser device in the embodiment of the present invention (I)-(k) Schematic structure figure which shows the manufacturing process of the dual wavelength high output laser apparatus in embodiment of this invention The figure which shows the electric current-light output characteristic of the dual wavelength high output laser apparatus in embodiment of this invention (A) Perspective view of a conventional two-wavelength semiconductor laser device, (b) AA cross-sectional view of the conventional two-wavelength semiconductor laser device. (A) Current-light output characteristics of a conventional dual wavelength laser device having a resonator length of 1000 μm, (b) Current-light output characteristics of a conventional dual wavelength laser device having a resonator length of 1800 μm.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Substrate 102 Infrared laser n-type cladding layer 103 Infrared laser active layer 104 Infrared laser p-type cladding layer 105 Current blocking layer 106 Contact layer 107 Infrared laser p-side electrode 108 Red laser n-type cladding layer 109 Red laser active layer 110 Red laser p-type cladding layer 111 Red laser p-side electrode 112 n-side electrode 113 Side etching promoting layer 120 Infrared laser element part 121 Red laser element part

Claims (6)

A first first-conductivity-type cladding layer, a first active layer, and a first second-conductivity-type cladding layer are sequentially formed on the etching promoting layer formed in the first laser element formation region on the semiconductor substrate. A first laminated structure forming step of depositing to form a first laminated structure;
A second stacked structure is formed by sequentially depositing a second first-conductivity-type cladding layer, a second active layer, and a second second-conductivity-type cladding layer in a second laser element formation region on the semiconductor substrate. A second laminated structure forming step of forming
By cleaving, a second semiconductor laser element portion having reflecting mirrors on both end faces is formed on the second laser element forming area, and a reflecting mirror, etc. on one side is formed on the first laser element forming area. A first cleaving step of forming a first semiconductor laser element portion material portion having an end face on the surface;
An acceleration layer etching step of removing the etching acceleration layer by etching at a predetermined depth from the end face of the first semiconductor laser element portion material portion;
The portion of the first laminated structure on the region where the etching acceleration layer removed by the acceleration layer etching process was removed is removed by cleavage, and the resonance direction is parallel to the second semiconductor laser element portion. And a second cleaving step of forming a first semiconductor laser element portion having a different wavelength and a resonance direction length shorter than that of the second semiconductor laser element portion. . In the first laminated structure forming step, the etching promoting layer, the first first conductivity type cladding layer, the first active layer, and the first second conductivity type cladding layer are formed on the semiconductor substrate. After sequentially depositing, the etching promoting layer, the first first conductivity type cladding layer, the first active layer, deposited on a region other than the first laser element formation region on the semiconductor substrate, And removing the first second-conductivity-type cladding layer to form the first laminated structure,
In the second stacked structure forming step, the second first-conductivity-type cladding layer, the second active layer, and the second active layer are formed on the semiconductor substrate including the first stacked structure formed in the first stacked structure forming step. And a second first-conductivity-type cladding layer deposited on a region other than the second laser element formation region on the semiconductor substrate after sequentially depositing a layer and the second second-conductivity-type cladding layer. 2. The method of manufacturing a semiconductor laser device according to claim 1, wherein the second stacked structure is formed by removing a layer, the second active layer, and the second second-conductivity-type cladding layer. The etching acceleration layer has a higher etching rate than both the semiconductor substrate and the first first conductivity type cladding layer,
In the accelerating layer etching step, a portion excluding a portion of the etching accelerating layer to be removed and a portion of the semiconductor substrate adjacent thereto and a portion of the first first conductivity type cladding layer is masked. The method of manufacturing a semiconductor laser device according to claim 1, wherein etching is performed.   4. The method of manufacturing a semiconductor laser device according to claim 3, wherein the etching promoting layer has an Al composition ratio larger than both of the semiconductor substrate and the first first-conductivity-type cladding layer. A semiconductor substrate;
A first semiconductor laser element section having a first first-conductivity-type cladding layer, a first active layer, and a first second-conductivity-type cladding layer, which are sequentially stacked on the semiconductor substrate;
The first semiconductor laser element unit includes a second first-conductivity-type cladding layer, a second active layer, and a second second-conductivity-type cladding layer, which are sequentially stacked on the semiconductor substrate. A semiconductor laser device comprising: a second semiconductor laser element portion having a parallel resonance direction and a different wavelength of emitted laser light and having a resonance direction length longer than that of the first semiconductor laser element portion. The first semiconductor laser element portion has an etching rate between the semiconductor substrate and the first first conductivity type cladding layer, which is higher than that of either the semiconductor substrate or the first first conductivity type cladding layer. 6. The semiconductor laser device according to claim 5, comprising a fast etching promoting layer.

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