JP2023000813A - Semiconductor laser array, method for manufacturing semiconductor laser array, laser module, semiconductor laser processing apparatus, and single crystal substrate - Google Patents

Abstract

To provide a semiconductor laser array capable of reducing a current required for oscillating the laser light.SOLUTION: A semiconductor laser array includes: an insulating single crystal part; a single crystal substrate that has a first conductive single-crystal portion and a second conductive single-crystal portion which are separated from each other by the insulating single-crystal part; and an emitter part that emits laser light from the end face. The semiconductor laser array includes: a first laminated structure and a second laminated structure each placed on the surface of the first conductive single crystal part and the second surface conductive single crystal part; a first p-side electrode and a second p-side electrode each placed in the first laminated structure and the second laminated structure respectively; and a first n-side electrode and a second n-side electrode are provided on the rear surface of the first conductive single crystal part and the rear surface of the second conductive single crystal part, respectively.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a monolithic semiconductor laser array, a semiconductor laser array manufacturing method, a laser module, a semiconductor laser processing apparatus, and a single crystal substrate.

In recent years, expectations are high for laser processing of various materials such as copper, gold, and resin. For example, in the automobile industry, electrification, miniaturization, high rigidity, improvement in design flexibility, improvement in productivity, etc. are required, and expectations for laser processing are high.

In particular, when laser light is used to process metals such as copper in the manufacture of motors and batteries for electric vehicles, it is necessary to output laser light with a high light absorption efficiency of bluish violet to blue (wavelength 350 nm to 450 nm). It is necessary to use a laser light source capable of In addition, in order to realize laser processing with high productivity, a laser light source with high output and high beam quality with high convergence is required.

Therefore, there is a demand for the development of a laser processing apparatus that outputs laser light with high output and high beam quality by condensing a plurality of laser lights. For example, Patent Literature 1 discloses a Wavelength Beam Combining (WBC) system for condensing laser beams output from a plurality of beam emitters arranged one-dimensionally. A WBC-type laser processing apparatus uses a monolithic semiconductor laser array capable of one-dimensionally arranging beam emitters with high accuracy.

JP 2015-106707 A

In order to obtain laser light capable of metal processing in a WBC laser processing apparatus, it is necessary to apply a high current to the semiconductor laser array. Therefore, a power supply device with a large capacity is required.

An object of the present disclosure is to provide a monolithic semiconductor laser array, a semiconductor laser array manufacturing method, a laser module, a semiconductor laser processing apparatus, and a single crystal substrate that can reduce the current required for laser light oscillation.

The semiconductor laser array of the present disclosure comprises:
a single crystal substrate having an insulating single crystal portion and a first conductive single crystal portion and a second conductive single crystal portion separated from each other by the insulating single crystal portion;
a first laminated structure having an emitter portion for emitting a laser beam from an end face, and arranged on the surface of the first conductive single crystal portion and the surface of the second conductive single crystal portion; a second laminated structure;
a first p-side electrode and a second p-side electrode arranged on the first laminated structure and the second laminated structure, respectively;
a first n-side electrode and a second n-side electrode respectively arranged on the rear surface of the first conductive single crystal portion and the rear surface of the second conductive single crystal portion;
Prepare.

The method for manufacturing a semiconductor laser array of the present disclosure includes:
forming an insulating single crystal;
forming a protrusion on the surface of the insulating single crystal;
forming a conductive single crystal in a region including the protrusion on the surface of the insulating single crystal;
The surface of the conductive single crystal is processed to expose the conductive single crystal and the insulating single crystal, and the back surface of the insulating single crystal is processed to obtain an insulating layer made of the insulating single crystal. forming a single crystal portion and a first conductive single crystal portion and a second conductive single crystal portion made of the conductive single crystal and separated from each other by the insulating single crystal portion;
A first laminated structure and a second laminated structure having an emitter for emitting a laser beam from an end face are provided on the surface of the first conductive single crystal portion and the surface of the second conductive single crystal portion. forming;
forming a first p-side electrode and a second p-side electrode on respective surfaces of the first laminated structure and the second laminated structure;
forming a first n-side electrode and a second n-side electrode on the back surface of the first conductive single crystal portion and the back surface of the second conductive single crystal portion;
Prepare.

The laser module of the present disclosure includes
a semiconductor laser array as described above;
a p-side electrode block connected to the second p-side electrode;
an n-side electrode block connected to the first n-side electrode;
a connector that electrically connects the p-side electrode block and the n-side electrode block;
a beam twister unit arranged on the end face side of the emitter section of the first laminated structure and the second laminated structure;
Prepare.

A semiconductor laser processing apparatus of the present disclosure includes the laser module described above.

The single crystal substrate of the present disclosure is
A compound semiconductor single crystal substrate used for manufacturing a semiconductor laser array,
an insulating single crystal portion;
a first conductive single crystal portion and a second conductive single crystal portion separated from each other by the insulating single crystal portion;
with
The insulating single-crystal portion, the first conductive single-crystal portion, and the second conductive single-crystal portion are exposed on one main surface of the single-crystal substrate.

According to the present disclosure, it is possible to provide a semiconductor laser array, a semiconductor laser array manufacturing method, a laser module, a semiconductor laser processing apparatus, and a single crystal substrate that can reduce the current required for laser light oscillation.

FIG. 1 is a conceptual diagram of a wavelength beam coupling type semiconductor laser processing apparatus. FIG. 2 is a perspective view showing a conventional monolithic semiconductor laser array. FIG. 3 is a perspective view of a monolithic semiconductor laser array according to this embodiment. FIG. 4 is a diagram showing a manufacturing process of a single crystal substrate according to the embodiment. FIG. 5 is a side view of a single crystal substrate and a monolithic semiconductor laser array according to the embodiment. FIG. 6 is a diagram showing the semiconductor laser array manufactured by the semiconductor laser array manufacturing method according to the embodiment, together with the dimensions of each part. FIG. 7 is a diagram showing a manufacturing process of the semiconductor laser array according to the embodiment. FIG. 8 is a diagram illustrating pattern formation on the surface of an intermediate product in the manufacturing process of the semiconductor laser array according to the embodiment. FIG. 9 is a diagram illustrating a laser module according to this embodiment. FIG. 10 is a schematic diagram of a semiconductor laser processing apparatus according to this embodiment.

First, a description will be given of how the present disclosure led to a monolithic semiconductor laser array, a method for manufacturing a semiconductor laser array, a laser module, a semiconductor laser processing apparatus, and a single crystal substrate.

FIG. 1 is a conceptual diagram of a WBC semiconductor laser processing apparatus (hereinafter also referred to as "processing apparatus") 800. As shown in FIG. FIG. 2 is a perspective view showing a conventional monolithic semiconductor laser array 10. As shown in FIG.

A WBC processing apparatus 800 includes a semiconductor laser array 10 , a beam twister unit 325 , a diffraction grating 326 and an external resonance mirror 328 .

A conventional semiconductor laser array 10 comprises a conductive single crystal substrate 12 , a laminated structure 14 , a p-side electrode 18 and an n-side electrode 19 . The laminated structure 14 is an operation layer in which the semiconductor layers 16 and 17 and the light emitting layer 15 are laminated, and has a plurality of emitter sections 3 for emitting the laser light 1 built therein.

Moreover, the semiconductor laser array 10 has a ridge stripe structure, and a plurality of emitter portions 3 are formed in stripes. In the laminated structure 14 , the laser beam 1 is emitted from one end surface of the emitter section 3 . Hereinafter, the end surface of the semiconductor laser array 10 from which the laser light 1 is emitted is referred to as the "output end surface", and the end surface opposite to the output end surface and from which the laser light 1 is not emitted is referred to as the non-emission end surface.

The width of the emitter section 3 in the direction in which the plurality of emitter sections 3 are arranged is called the emitter width. The longitudinal dimension of the emitter section 3, that is, the dimension from the emitting facet to the non-emitting facet is called the cavity length.

The p-side electrode 18 includes an emitter electrode portion 83 arranged on the surface of each emitter portion 3 (upper surface of the convex portion 31) and a pad electrode portion 84 arranged across a plurality of emitter electrode portions 83. I have. Also, the n-side electrode 19 is arranged on the back surface of the conductive single crystal substrate 12 .

A reflecting film 21 is provided on the emission end face of the semiconductor laser array 10, and a reflecting film 22 is provided on the non-emitting end face.

A beam twister unit 325 is provided for each semiconductor laser array 10 . The beam twister unit 325 rotates the plurality of laser beams 1 emitted from the plurality of semiconductor laser arrays 10 by 90°. This prevents a plurality of laser beams 1 having wavelengths close to each other from interfering with each other.

Diffraction grating 326 is a transmissive or reflective diffraction grating. FIG. 1 shows that diffraction grating 326 is a transmissive diffraction grating. Thus, when the diffraction grating 326 is a transmissive diffraction grating, the diffraction grating 326 diffracts the incident laser beam 1 at an output angle (diffraction angle) β according to the wavelength of the laser beam 1, 327.

The external resonant mirror 328 is a partially transmissive mirror.

A laser beam 327 emitted from the diffraction grating 326 is incident on an external resonance mirror 328 , and a part of the laser beam 330 is vertically reflected toward the diffraction grating 326 by the external resonance mirror 328 . As a result, a laser beam having a predetermined lock wavelength causes external resonance between the reflection film 22 on the non-emitting end face and the external resonance mirror 28, and a laser beam 329 is output from the external resonance mirror 28. FIG. Here, the lock wavelength is uniquely determined by the positional relationship among the individual emitters 3 of the semiconductor laser array 10, the diffraction grating 326, and the external resonant mirror 328. FIG.

For example, in order to obtain a laser light output of 2 W from a semiconductor laser device having a single emitter portion 3 that satisfies the following conditions (1) to (3), it is necessary to supply a current of about 2 A to the semiconductor laser device. There is
(1) Emitter width is 15 μm
(2) The resonator length is 2000 μm
(3) The main material is gallium nitride (hereinafter referred to as GaN)
Nitride semiconductors mainly composed of GaN are substances capable of emitting light in the wavelength range from the ultraviolet region to the infrared region, and there are reports of semiconductor lasers emitting light in the wavelength range of about 380 nm to about 540 nm.

In the semiconductor laser array 10 of FIG. 2, a plurality of emitter sections 3 operate in parallel. Therefore, as the number of emitter sections 3 increases, the current value required to oscillate the laser light 329 increases.

For example, in order to obtain an output of laser light 329 of 80 W from the semiconductor laser array 10 having 40 emitter portions 3 satisfying the above conditions (1) to (3), 2A×40 (40 is the number of emitter portions 3 number), that is, a power supply capable of passing a current of about 80A is required.

The inventor of the present invention operates some groups in series with other groups instead of operating all of the plurality of emitter sections of the semiconductor laser array in parallel, thereby reducing the current required for laser light oscillation. We have found that it can be reduced.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the embodiments described below, numerical values, shapes, materials, components, arrangement positions of components, connection forms, processes (steps), order of processes, etc. are only examples. There is no gist to limit the disclosure. Therefore, among constituent elements in the following embodiments, constituent elements that are not described in independent claims representing the highest concept of the present disclosure will be described as optional constituent elements.

Each figure is a schematic diagram and is not strictly illustrated. Therefore, the scales and the like in each drawing are not necessarily the same. In each figure, substantially the same configurations are given the same reference numerals, and duplicate descriptions are omitted or simplified.

[Embodiment]
(semiconductor laser array)
FIG. 3 is a perspective view of the semiconductor laser array 100 according to this embodiment. Note that FIG. 3 shows only a total of six protrusions 131 for the sake of simplicity. A semiconductor laser array 100 according to the present embodiment will be described as a GaN-based semiconductor laser array that emits laser light 1 in a wavelength band of 405 nm or more and 450 nm or less.

The semiconductor laser array 100 includes a single crystal substrate 110, a first laminated structure 141, a second laminated structure 142, a first p-side electrode 181, a second p-side electrode 182, and a first n-side electrode 191. , a second n-side electrode 192 , a reflective film 211 and a reflective film 212 . The semiconductor laser array 100 has a ridge stripe structure, and a plurality of emitter sections 130 are formed in stripes. That is, the semiconductor laser array 100 is a monolithic semiconductor laser array in which a plurality of emitter sections 130 are formed on a single single crystal substrate 110 .

The single-crystal substrate 110 is a single-crystal substrate of a GaN-based compound semiconductor, and includes an insulating single-crystal portion 111 , a first conductive single-crystal portion 121 and a second conductive single-crystal portion 122 .

The insulating single crystal portion 111 is made of, for example, an undoped GaN single crystal. The first conductive single crystal portion 121 and the second conductive single crystal portion 122 are separated from each other by the insulating single crystal portion 11 . The first conductive single crystal part 121 and the second conductive single crystal part 122 are made of, for example, a conductive Si-doped GaN single crystal formed by doping GaN with Si. Hereinafter, when the first conductive single-crystal portion 121 and the second conductive single-crystal portion 122 are not distinguished from each other, they are referred to as "conductive single-crystal portion 120".

The first laminated structure 141 and the second laminated structure 142 are provided separately from each other on the first conductive single crystal part 121 and the second conductive single crystal part 122 of the single crystal substrate 110. It is A first p-side electrode 181 and a second p-side electrode 182 are provided on the first laminated structure 141 and the second laminated structure 142, respectively. In addition, a first n-side electrode 191 and a second n-side electrode 192 are spaced apart from each other on the rear surfaces of the first conductive single-crystal portion 121 and the second conductive single-crystal portion 122 of the single-crystal substrate 110 . is provided. Hereinafter, when the first p-side electrode 181 and the second p-side electrode 182 are not distinguished, they are referred to as "p-side electrode 180", and when the first n-side electrode 191 and the second n-side electrode 192 are not distinguished. , is referred to as "n-side electrode 190".

The first laminated structure 141 and the second laminated structure 142 function as operating layers. The first laminated structure 141 and the second laminated structure 142 each include a first semiconductor layer 160, a light emitting layer 150, and a second semiconductor layer 170. As shown in FIG.

The first semiconductor layer 160 is made of, for example, an n-type semiconductor such as AlGaN.

The light emitting layer 150 has a structure in which a multiple quantum well layer is sandwiched between guide layers. The multiple quantum well layers are made of undoped InGaN, for example. The guide layer is made of, for example, undoped GaN.

The composition ratio of the light emitting layer 150 is adjusted according to the gain wavelength. The lock wavelength (at the central portion of the semiconductor laser array 100) of the WBC processing apparatus 801 (see FIG. 10) having the semiconductor laser array 100 has a width of, for example, 435.9 nm or more and 450.0 nm or less. When mounting the semiconductor laser array 100 on the processing apparatus 801, it is necessary to match the gain wavelength of the semiconductor laser array 100 with the lock wavelength.

The gain wavelength can be adjusted by adjusting the composition ratio of the light emitting layer 150 . Specifically, the gain wavelength can be adjusted by adjusting the In composition ratio of the multiple quantum well layers made of InGaN in the light emitting layer 150 . For example, when the In composition ratio is set to 17%, the average gain wavelength of the semiconductor laser array 100 is 450 nm. In addition, a semiconductor laser array having different gain wavelengths may be formed by adjusting the In composition for each emitter section 130 by adjusting the temperature distribution when forming the light emitting layer 150 .

The second semiconductor layer 170 is configured by laminating an electron overflow suppression layer, a clad layer, and a contact layer in order from the light emitting layer 150 side. The electron overflow suppression layer and the clad layer are made of a p-type semiconductor such as AlGaN, and the contact layer is made of a p-type semiconductor such as GaN. A p-side electrode 180 is arranged on the contact layer.

Next, the emitter section 130 will be described.
A plurality of protrusions 131 are formed in stripes on the second semiconductor layer 170 . An optical waveguide portion for confining light is formed under the convex portion 131 due to the refractive index difference between the light emitting layer 150 and the first semiconductor layer 160 and the refractive index difference between the light emitting layer 150 and the second semiconductor layer 170. there is In the first layered structure 141 and the second layered structure 142 , portions directly below the convex portions 131 form individual emitter portions 130 . A laser beam 1 is emitted from one end surface of the emitter section 130 .

The emitter width (that is, the width of the convex portion 131) of the semiconductor laser array 100 used in the WBC processing apparatus 801 (see FIG. 10) is generally set to be 10 μm or more and 40 μm or less. . In this embodiment, for example, the width of the emitter section 130 is 15 μm. The width of the semiconductor laser array 100 in the direction in which the convex portions 131 are arranged (hereinafter referred to as “array width”) depends on the number of emitter portions 130, the spacing between the emitter portions 130, and the width of the insulating single crystal portion 111. determined based on

In this embodiment, for example, the resonator length is 2000 μm, the array width is 11000 μm, the number of emitter sections 130 in each of the first laminated structure 141 and the second laminated structure 142 is 20 (40 in total), Also, the width of the insulating single crystal portion 11 is 1000 μm. Further, in each of the first laminated structure 141 and the second laminated structure 142, the emitter sections 130 are arranged at intervals of 250 μm, that is, between one end of the emitter section 130 in the width direction and the width direction of the adjacent emitter section 130. It is formed so that the dimension between one end is 250 μm.

Hereinafter, the layers including the first semiconductor layer 160, the light-emitting layer 150, and the second semiconductor layer 170 may be collectively referred to as "laminated structure 140".

The first p-side electrode 181 and the second p-side electrode 182 have a plurality of emitter electrode portions 183 and pad electrode portions 184 . The emitter electrode portion 183 is formed on the top surface of each emitter portion 130, more specifically, on the top surface of the contact layer, and is connected to the top surface of the optical waveguide portion via the contact layer. The emitter electrode portion 183 is an electrode that makes ohmic contact with the contact layer above each optical waveguide portion.

The emitter electrode portion 183 is made of a metal material such as Pd, Pt, Ni, or the like. In this embodiment, the emitter electrode portion 183 has a two-layer structure made of Pd and Pt.

The surfaces (upper surfaces) of the first laminated structure 141 and the second laminated structure 142 excluding the emitter electrode portion 183 and the upper surface of the insulating single crystal portion 111 are covered with an insulating film. Specifically, the insulating film covers the upper surfaces of the cladding layer and the contact layer where the emitter electrode portion 183 is not formed. The insulating film is made of, for example, SiO ₂ .

The pad electrode portion 184 is arranged so as to be in contact with the plurality of emitter electrode portions 183 . As a result, the plurality of emitter sections 130 of the first laminated structure 141 are connected in parallel to the pad electrode section 184 of the first p-side electrode 181, and the plurality of emitter sections 130 of the second laminated structure 142 are connected in parallel. , are connected in parallel to the pad electrode portion 184 of the second p-side electrode 182 .

A first n-side electrode 191 and a second n-side electrode 192 are formed on the rear surface of the first conductive single crystal portion 121 and the rear surface of the second conductive single crystal portion 122 .

A reflective film 211 is formed on the end face (output end face) of the semiconductor laser array 100 from which the laser light 1 is emitted. The reflective film 211 is a dielectric multilayer film formed by combining a silicon dioxide (SiO ₂ ) layer and an aluminum oxide (Al ₂ O ₃ ) layer. The reflectance of the reflective film 211 can be changed by adjusting the thickness of each layer and the refractive index of each layer. For example, when the gain wavelength _λg of the semiconductor laser array 10 is 450 nm, the reflectance of the reflective film 211 is set to 0.01%.

A reflective film 212 is formed on the end face (non-radiation end face) of the semiconductor laser array 100 opposite to the emission end face. The reflective film 212 is a dielectric multilayer film formed by combining a SiO ₂ layer and an aluminum oxynitride (AlON) layer. As with the reflective film 211, the reflectance of the reflective film 212 can be changed by adjusting the thickness of each layer and the refractive index of each layer. For example, when the gain wavelength _λg of the semiconductor laser array 10 is 450 nm, the reflectivity of the reflective film 212 is set to 98.7%.

(Manufacturing method of single crystal substrate)
Next, a method for manufacturing the single crystal substrate 110 according to the embodiment will be described. FIG. 4 is a diagram showing a manufacturing process of a single crystal substrate 110 (hereinafter also referred to as an "isolation GaN substrate") according to the embodiment.

<Step S1 Base material preparation>
First, the base material 510 is prepared. The material of the base material 510 is, for example, sapphire, ScAlMgO ₄ , GaN, or the like. The material and shape of the base material 510 are not particularly limited. For example, the shape of the main surface of the base material 510 may be hexagonal or circular.

<Step S2 Insulating Single Crystal Growth>
Next, an insulating GaN single crystal is grown on the base material 510 by Hydride Vapor Phase Epitaxy (HVPE) to form an insulating single crystal 520 having a thickness of, for example, 1 mm. do.

In step S2, it is desirable to reduce the crystallinity of the insulating single crystal 520 by growing the crystal at a growth temperature of 900° C. or higher and 950° C. or lower. Thereby, the warp of the single crystal substrate 110 can be alleviated. Therefore, it is possible to reduce the occurrence of defects caused by warpage of the single crystal substrate 110 in subsequent steps. These defects include, for example, cracks and variations in light emitting positions when the semiconductor laser array 100 is constructed. Furthermore, in step S2, the crystallinity of the insulating single crystal 520 does not have to be increased so much, so the growth rate can be increased. Therefore, the single crystal substrate 110 can be manufactured inexpensively and in a short time.

In the crystal growth in step S2, what kind of crystal growth method can be used if a crystal of an insulating semiconductor having a high resistivity is obtained instead of an n-type semiconductor or a p-type semiconductor obtained by adding Si or Mg? may be adopted. For example, a liquid phase method known as a Na flux method or an ammonothermal method may be employed.

<Step S3 Insulating Single Crystal Processing>
First, the base material 510 is separated from the insulating single crystal 520 by polishing and/or grinding the base material 510 . As a result, warping of the insulating single crystal 520 due to the lattice constant mismatch between the insulating single crystal 520 and the base material 510 can be avoided.

Next, the surface layer of the insulating single crystal 520 is removed by grinding the surface of the insulating single crystal 520 by about 0.1 mm. Next, the surface of the insulating single crystal 520 is polished by chemical mechanical polishing (CMP) to mirror finish.

Next, an etching mask with a width of 1 mm is formed on the surface of the insulating single crystal 520 by normal photolithography. Then, the insulating single crystal 520 is dry-etched using a chlorine-based gas, and the surface of the insulating single crystal 520 is etched with a width of, for example, 1 mm (more specifically, the width at the lowermost portion) and a 0.0 mm thickness. Protrusions 530 with a height of 2 mm are formed. Note that the cross-sectional shape of the projecting portion 530 may be any of a triangle, a square, and a trapezoid. FIG. 4 shows that the cross-sectional shape of the protrusion is triangular. On the surface of insulating single crystal 520 , protrusion 530 extends from one end of insulating single crystal 520 to the other.

Thereafter, cleaning treatment such as RCA cleaning is performed to remove adhering substances such as trace metals on the surface of the insulating single crystal portion 11 .

<Step S4 Conductive Single Crystal Growth>
A conductive GaN crystal is crystal-grown by HVPE in a region including the protruding portion 530 on the surface of the insulating single crystal 520 with a clean surface to form a conductive single crystal 540 having a thickness of, for example, 0.2 mm. do. Here, by doping GaN with Si having an atomic density of about 1×10 ¹⁸ cm ⁻³ as an impurity, a conductive single crystal 540 that is a Si-doped GaN crystal having n-type conductivity can be obtained.

<Step S5 Wafer processing>
Next, the surface of the conductive single crystal 540 is processed to expose the conductive single crystal 540 and the insulating single crystal 520 on the surface, and the back surface of the insulating single crystal 520 is processed to expose the insulating single crystal 520. thin. Thus, the insulating single crystal portion 111 made of the insulating single crystal 520 and the first conductive single crystal portion 121 and the first conductive single crystal portion 121 made of the conductive single crystal 540 and separated from each other by the insulating single crystal portion 111 are formed. 2 conductive single crystal portions 122 are formed. The step S5 will be described in detail below.

First, the back surface layer of the insulating single crystal 520 is removed by grinding and/or polishing by about 0.3 mm.

Further, the surface of the conductive single crystal 540 and the protrusion 530 are ground until the height of the protrusion 530 reaches 0.1 mm, and the surface layers of the conductive single crystal 540 and the protrusion 530 are removed. Thereby, the conductive single crystal 540 and the insulating single crystal 520 are exposed to the surface. At this exposed surface, the surface area of the conductive single crystal 540 is separated into multiple areas by the surface areas of the insulating single crystal 520 .

Through steps S1 to S5, the single crystal substrate 110 having the insulating single crystal portion 111, the first conductive single crystal portion 121, and the second conductive single crystal portion 122 exposed on one main surface is obtained. It is formed.

Actually, in step S5, the single crystal substrate 110 is processed into a wafer having a shape suitable for manufacturing a monolithic semiconductor laser array. For example, the single crystal substrate 110 is processed into a circular shape with a diameter of 50 mm. In addition, an orientation flat indicating the crystal orientation may be formed on the single crystal substrate 110, and bevel processing may be performed on the circular outer periphery of the single crystal substrate 110. FIG. As a result, the single crystal substrate 110 can be appropriately installed in each device used in the manufacturing process of the semiconductor laser array 100, and film formation and processing can be performed.

Further, the surface of the single-crystal substrate 110 where the insulating single-crystal portion 111, the first conductive single-crystal portion 121, and the second conductive single-crystal portion 122 are exposed is polished by CMP and mirror-finished. . Thereafter, cleaning treatment such as RCA cleaning is performed to remove adhering substances such as trace metals on the surface of the single crystal substrate 110 .

Also, although FIG. 4 shows that only one protrusion 530 is formed, any number of protrusions 530 may be formed. When n (an integer equal to or greater than 1) protruding portions 530 are formed, the single crystal substrate 110 has n+1 conductive single crystal portions 120 separated from each other.

(Manufacturing method of semiconductor laser array)
Next, a method for manufacturing the semiconductor laser array 100 according to the embodiment will be described with reference to FIGS. 5 to 8. FIG. FIG. 5 is a side view of the single crystal substrate 110 and the semiconductor laser array 10 according to the embodiment. FIG. 6 is a diagram showing the semiconductor laser array 100 manufactured by the manufacturing method of the semiconductor laser array 100 according to the embodiment together with the dimensions of each part. FIG. 7 is a diagram showing a manufacturing process of the semiconductor laser array 100 according to the embodiment. FIG. 8 is a diagram illustrating pattern formation on the surface of an intermediate product in the manufacturing process of the semiconductor laser array 100 according to the embodiment.

As shown in FIG. 5, by performing the following steps S11 to S15 on the single crystal substrate 110, the single crystal substrate 110, the first laminated structure 141, and the second laminated structure 142 are formed. , the first p-side electrode 181, the second p-side electrode 182, the first n-side electrode 191, the second n-side electrode 192, the reflective film 211, and the reflective film 212 are manufactured. . The steps S11 to S15 will be described in detail below.

<Step S11 Single Crystal Substrate Preparation>
First, a single crystal substrate 110 (isolation GaN substrate) is manufactured. The manufacturing method is as described above. In FIG. 7, the surface of the conductive single crystal portion 120 in the surface of the single crystal substrate 110 is hatched.

<Step S12 Laminated Structure Formation>
Next, a laminated structure 140 is formed on the surfaces of the plurality of conductive single crystal portions 120 . Step S12 includes steps S121 and S122.

<<Step S121 Multilayer Formation>>
Crystal growth is performed using a metal organic chemical vapor deposition (MOCVD) method to form a multilayer 560 on the surface of a single crystal substrate 110 having a thickness of 500 μm. Specifically, a first semiconductor layer 160, a light emitting layer 150, and a second semiconductor layer 170 are formed over a single crystal substrate 110 with a thickness of 500 μm. Here, a multiple layer 560 is formed on the surface of the conductive single crystal portion 120 . Specifically, the surface of the insulating single-crystal portion 111 is previously covered with, for example, a SiO ₂ film. As a result, the multiple layer 560 is not formed on the insulating single-crystal portion 111 , and the multiple layer 560 is formed only on the surface of the conductive single-crystal portion 120 . After forming the multilayer 560, the SiO ₂ film on the insulating single crystal portion 111 is removed by etching.

When the light-emitting layer 150 is made of InGaN, in the step S121, by setting the In composition to about 10% or more and 17% or less, the emitter section 130 has a different gain wavelength in the range of 400 nm or more and 450 nm or less. A laser array 100 can be obtained.

<<Step S122 Multi-layer processing>>
Next, using ordinary photolithography, the surface of the multiple layer 560 formed on the single crystal substrate 110 with a diameter of 50 mm is patterned to manufacture the semiconductor laser array 100 that satisfies the following conditions (Figure). 6).
(A) The resonator length is 2000 μm
(B) Array width is 11000 μm
(C) A total of 40 emitter units 130 (20×2 groups)
(D) The width of the laminated structure is 5000 μm

In the pattern formation, 40 pattern regions corresponding to the projections 131 are formed in the pattern region corresponding to the outer shape of the semiconductor laser array 100, and the 20th pattern region from one end and the 21st pattern region from the one end. The pattern is formed so that each pattern region is separated from each other by 1000 μm. That is, between the central portion of the pattern region corresponding to the semiconductor laser array 100, that is, the 20th pattern region from one end and the 21st pattern region from the one end, the protruding portion of the insulating single crystal portion 111 The pattern is formed so that the portion corresponding to 530 is located. FIG. 8 shows a plan view of the intermediate product consisting of single crystal substrate 110 and multiple layers 560 after patterning.

Next, an etching mask having a width of 15 μm is formed in stripes on the surface of the multilayer 560 . Then, the second semiconductor layer 170 of the multilayer 560 is dry-etched using a chlorine-based gas. In this etching, the etching targets are the contact layer (the uppermost layer of the second semiconductor layer 170) and the cladding layer (the layer immediately below the contact layer), and the etching depth is from the uppermost surface of the contact layer. This corresponds to the layer thickness over the bottom surface of the contact layer, thereby forming a number of protrusions 131 in the multilayer 560 .

Accordingly, a laminated structure 140 is formed on the surface of each conductive single crystal portion 120 . This laminated structure 140 has 20 emitter portions 130 each having an emitter width of 15 μm and a resonator length of 2000 μm.

<Step S13 Electrode Formation>
An insulating film is formed on the surface of the single-crystal substrate 110 and the region including the projections 131 on the surface of the multilayer structure 140 by using a CVD method or the like. This insulating film is a silicon dioxide (SiO2) layer. Then, normal photolithography is performed several times to remove the predetermined region of the convex portion 131 and the insulating film on the insulating single crystal portion 111 .

Next, an emitter electrode portion 183 is formed using Pd or Pt as a material in the region of the convex portion 131 from which the insulating film has been removed. Then, one pad electrode portion 184 is formed for one laminated structure 140 so as to be in contact with the plurality of emitter electrode portions 183 . Thereby, the emitter section 130 is connected in parallel to the p-side electrode 180 .

Next, the back surface of the insulating single-crystal portion 111 is polished or etched so as to have a thickness of about 80 μm. As a result, as shown in FIG. 5, the insulating single-crystal portion 111 and the conductive single-crystal portion 120 are exposed also on the rear surface side of the single-crystal substrate 110 .

Thinning of the single crystal substrate 110 enables cleavage. In addition, since the single-crystal substrate 110 is thin, the heat dissipation of the finally completed semiconductor laser array 100 can be improved.

Next, an n-side electrode 190 is formed by vapor-depositing titanium and gold on the back surface of each conductive single crystal portion 120 and performing an alloying process. Neither the pad electrode portion 184 nor the n-side electrode 190 is formed on the front and back surfaces of the insulating single crystal portion 111 .

<Step S14 Cut out>
Next, the single crystal substrate 110 is cleaved using the m-plane cleaving property of the single crystal substrate 110 to obtain the single crystal substrate 110, the two laminated structures 140, the two p-side electrodes 180, and the two n-planes. An array body portion 99 consisting of side electrodes 190 is cut out. In this embodiment, 60 array body portions 99 are cut out (see FIGS. 7 and 8).

<Step S15 Reflective Film Formation>
Next, a reflective film 211 is formed on the outgoing end face of the array main body 99 and a reflective film 212 is formed on the non-emitting end face of the array main body 99 . In addition, it is desirable that the light passes through the reflective film 211 when the semiconductor laser array 100, which is the intended product, is mounted on the processing apparatus 801 of the WBC system. Therefore, the reflective film 211 is formed so that the reflectance of the reflective film 211 is 0.5% or less at the gain wavelength of the semiconductor laser array 100, for example, 405 nm.

In addition, in the WBC processing apparatus 801, it is desirable that light does not pass through the reflecting film 212 on the non-emitting end face. Therefore, the reflective film 212 is formed so that the reflectance of the reflective film 212 is 90% or more at the gain wavelength of the semiconductor laser array 100, for example, 405 nm.

As described above, through steps S11 to S15, the semiconductor laser array 100 that satisfies the above (A) to (D) is formed.

When a pulse current of 30 A is injected into this semiconductor laser array 100 through a simple electrode block, laser light 1 having a total optical output of 70 W or more and 88 W or less can be obtained from 40 emitter sections 130. . That is, when a current of 1.5 A is injected into one emitter section 130, the laser light 1 with a relatively high optical output of 2.2 W at maximum can be obtained.

(Configuration of laser module)
A laser module 700 in which the semiconductor laser array 100 according to the present embodiment is mounted will be described below with reference to FIG. FIG. 9 is a diagram illustrating a laser module 700 according to this embodiment. The left side of FIG. 9 shows a perspective view of the laser module 700, and the right side of FIG. 9 shows an enlarged plan view showing the laser module 700 with the upper metal block 771 (described later) removed. ing.

The laser module 700 includes a semiconductor laser array 100, a first p-side electrode block 761, a first n-side electrode block 762, a second p-side electrode block 763, a second n-side electrode block 764, a connector 765 and A beam twister unit 325 is provided.

The first p-side electrode block 761 is connected to the first p-side electrode 181 of the semiconductor laser array 100 . The first n-side electrode block 762 is connected to the first n-side electrode 191 of the semiconductor laser array 100 .

The second p-side electrode block 763 is connected to the second p-side electrode 182 of the semiconductor laser array 100 . The second n-side electrode block 764 is connected to the second n-side electrode 192 of the semiconductor laser array 100 .

A connector 765 electrically connects the first n-side electrode block 762 and the second p-side electrode block 763 . Thereby, the emitter section 130 formed in the first laminated structure 141 and the emitter section 130 formed in the second laminated structure 142 are connected in series. Note that the connection body 765 may be composed of a bonding wire, or may be composed of a metal block.

The first p-side electrode block 761 is connected to the positive electrode of the power supply 830 (see FIG. 10) through an upper metal block 771, which will be described later, and the second n-side electrode block 764 is connected to the lower metal block, which will be described later. 772 to the negative terminal of power supply 830 (see FIG. 10).

Two submounts (not shown) are arranged on the n-side electrode 190 side of the semiconductor laser array 100 so as to correspond to the first n-side electrode 191 and the second n-side electrode 192, respectively. Since the semiconductor laser array 100 has a plurality of emitter sections 130, the power required for laser oscillation may be several tens of W or more. Therefore, the submount may be made of a conductive material and serve as a current path.

The submount may be made of an insulating material. In this case, the surface of the submount connected to the semiconductor laser array 100 may be plated with metal such as gold plating and copper plating to ensure conductivity.

The beam twister unit 725 is arranged on the emission end face side of the semiconductor laser array 100 . The beam twister unit 725 rotates the plurality of laser beams 1 emitted from the semiconductor laser array 100 by 90° to prevent mutual interference between individual laser beams 1 having similar wavelengths.

A laser module 700 is a module mounted on a WBC processing apparatus 801 .

In this embodiment, the semiconductor laser array 100 further includes an upper metal block 771, a lower metal block 772, and a water-cooling mount 773, and is configured as a high heat dissipation module that performs water cooling.

The upper metal block 771 and the lower metal block 772 are metal blocks with high heat dissipation, and are made of copper, for example. An upper metal block 771 and a lower metal block 772 are arranged above and below the semiconductor laser array 100, respectively.

Therefore, the laser module 700 has a structure in which the semiconductor laser array 100 can be cooled from the water-cooling mount 773 through the insulating heat conductive sheet (not shown) and the lower metal block 772 .

When a pulse current of 30 A is injected into the laser module 700 according to this embodiment, a laser beam 1 of 60 W or more and 80 W or less can be obtained. That is, a current of 30 A is injected into twenty emitter sections 130 and a current of 1.5 A is injected into one emitter section 130 . As a result, a maximum optical output of 2.0 W (80 W divided by 40 (the number of emitter sections 130)) can be obtained from one emitter section 130. FIG.

When current is injected into the semiconductor laser array 100 before being mounted on the laser module 700, a maximum optical output of 2.2 W is obtained from one emitter section 130. FIG. That is, by being mounted on the laser module 700 , the maximum value of the light output obtained from one emitter section 130 becomes smaller than before being mounted on the laser module 700 . The cause is considered to be distortion and damage of the emitter section 130 caused by mounting on the laser module 700 . It is also conceivable that the cooling of a part of the emitter section 130 was insufficient.

(Wavelength beam coupling type processing equipment)
Next, the configuration of the WBC-type processing apparatus 801 according to the present embodiment will be described with reference to FIG. FIG. 10 is a schematic diagram of a processing device 801 according to this embodiment. The cooling water path is omitted from FIG.

The processing device 801 has a plurality of laser modules 700 . In this embodiment, the processing apparatus 801 includes five laser modules 700 each equipped with a semiconductor laser array 100 having an array width of 11000 μm, a cavity length of 2000 μm, and 40 (20 pieces×2 groups) of emitter portions 130 . described as being The five laser modules 700 are hereinafter referred to as "laser module 701," "laser module 702," "laser module 703," "laser module 704," and "laser module 705."

The processing apparatus 801 further includes a housing 810 , multiple mirrors 820 , a diffraction grating 326 , an external resonant mirror 328 and a power supply 830 .

The housing 810 is made of stainless steel, for example, and laser modules 701 to 705 are arranged in a fan shape inside the housing 810 . FIG. 10 shows that laser module 701, laser module 702, laser module 703, laser module 704 and laser module 705 are arranged in this order. Laser modules 701 to 705 are injected with current in series from power supply 830 and emit laser light 1 .

Inside the housing 810, laser modules 701 to 705, a plurality of mirrors 820, a diffraction grating 326, and an external resonance mirror 328 are arranged.

Laser light 1 emitted from laser modules 701 to 705 is condensed onto diffraction grating 326 by a plurality of mirrors 820 . In this embodiment, the diffraction grating 326 is a transmissive diffraction grating and is arranged such that the distance from the emission end face of the semiconductor laser array 100 to the diffraction grating 326 is 2.6 m.

The incident angle α of the laser beam 1 with respect to the diffraction grating 326 varies depending on the position of the laser module from which the laser beam 1 is emitted. The incident angles α of the laser beams 1 from the laser modules 701, 702, 703, 704, and 705 are 21.6°, 22.4°, 23.2°, 24.0°, and 24.8°, respectively, It changes in increments of 0.8°. The emission angle β of the laser light 327 emitted from the diffraction grating 326 is 70°.

The lock wavelengths of the semiconductor laser arrays 100 of the laser modules 701 to 705 are uniquely determined by the positional relationship among the semiconductor laser arrays 100, the diffraction grating 326, and the external resonance mirror 328. Note that the lock wavelength shows slightly different values depending on the central portion and the edge portion of the semiconductor laser array 100 .

The lock wavelengths of the semiconductor laser array 100 in the processing apparatus 801 according to this embodiment are shown in Table 1 below.

The processing device 801 causes resonance between the external resonance mirror 328 and the non-emitting end face of the semiconductor laser array 10 to emit a part of the laser light 329 . Note that the reflectance of the external resonant mirror 328 is set to 15%.

(Manufacturing method of processing equipment)
First, it has a capacity that can accommodate a plurality of laser modules 701 to 705, a diffraction grating 326, a plurality of mirrors 820, and an external resonance mirror 328, and that can finely adjust their arrangement positions. A housing 810 is prepared.

Next, a plurality of mirrors 820, a plurality of mirrors 320, a diffraction grating 326, and an external resonance mirror 328 are arranged, and optical axis adjustment is performed to prevent optical axis deviation during external resonance. The optical axis adjustment is performed by arranging a predetermined semiconductor laser element at the arrangement position of the laser modules 701 to 705 and emitting a laser beam from the semiconductor laser element. The predetermined semiconductor laser element is, for example, a semiconductor element that emits visible laser light.

Next, a plurality of laser modules 700 are prepared. Then, internal resonance is generated between the emitting end face and the non-emitting end face of the semiconductor laser array 100 of the prepared laser module 700 to cause laser oscillation. At this time, it is desirable to measure each gain wavelength at the right end (one end), the left end (the other end), and the center of the semiconductor laser array 100 at the current value used in the processing device 801. . This is because the current flow causes the emitter section 130 to generate heat, which changes the bandgap of the light-emitting layer 150 of the semiconductor laser array 100, that is, the gain wavelength. .

In addition, since the output value and semiconductor characteristics change depending on the performance of the semiconductor laser array 100, it is necessary to measure the light output at a constant current value, the threshold current and threshold voltage required for laser oscillation, that is, the input power. is desirable.

Based on the measured gain wavelength of the semiconductor laser array 100, the laser module 700 having the semiconductor laser array 100 matching the lock wavelength of the processing apparatus 801 is selected. At this time, it is desirable to select a laser module 700 having a semiconductor laser array 100 capable of efficiently obtaining optical output through internal resonance. Assume that laser modules 701 to 705 are selected as a result of selection.

The laser modules 701 - 705 are then placed at appropriate locations inside the housing 810 . After that, the lid (not shown) of the housing 810 is closed so that the scattered light does not leak outside the housing 810 .

As described above, the WBC-type processing apparatus 801 is completed. After that, after the cooling mechanism of the processing device 801 is activated, the power supply device 830 is turned on, and the output value and quality of the laser light 329 emitted from the external resonance mirror 328 are measured to determine the performance of the processing device 801. Evaluate.

As described above, the semiconductor laser array 100 according to the present embodiment includes the insulating single crystal portion 111, and the first conductive single crystal portion 121 and the second conductive single crystal portion 121 separated from each other by the insulating single crystal portion 111. A single crystal substrate 110 having a conductive single crystal portion 122 and an emitter portion 130 for emitting a laser beam 1 from an end face. The first laminated structure 141 and the second laminated structure 142 respectively arranged on the surface of the crystal part 122 and the first laminated structure 141 arranged on the first laminated structure 141 and the second laminated structure 142 respectively. a p-side electrode 181 and a second p-side electrode 182; and a second n-side electrode 192 .

Thereby, the plurality of emitter sections 130 of the semiconductor laser array 100 are divided into a plurality of groups, and the emitter sections 130 belonging to at least one group operate in series with the emitter sections 130 belonging to another group. . Therefore, the current required for oscillation of the laser light 1 can be reduced. As a result, the capacity of the power supply device 830 that supplies current to the processing device 801 having the semiconductor laser array 100 can be reduced, so that the size reduction of the power source device 830 and the processing device 801 can be realized.

In addition, in the present embodiment, each of the first laminated structure 141 and the second laminated structure 142 has a plurality of emitter portions 130, and the plurality of emitter portions 130 of the first laminated structure 141 are , are connected in parallel to the first p-side electrode 181 , and the plurality of emitter portions 130 of the second laminated structure 142 are connected in parallel to the second p-side electrode 182 .

Further, the method of manufacturing the semiconductor laser array 100 according to the present embodiment includes the steps of forming the insulating single crystal 520, forming the protruding portion 530 on the surface of the insulating single crystal 520, and forming the insulating single crystal 520. A step of forming a conductive single crystal 540 in a region including a protruding portion 530 on the surface; By processing the back surface of the insulating single crystal 520 , the insulating single crystal portion 111 made of the insulating single crystal 520 and the first insulating single crystal portion 111 made of the conductive single crystal 540 and separated from each other by the insulating single crystal portion 111 are formed. forming a conductive single crystal portion 121 and a second conductive single crystal portion 122; , a step of forming on the surface of the first conductive single-crystal portion 121 and the surface of the second conductive single-crystal portion 122; a step of forming a first p-side electrode 181 and a second p-side electrode 182; and forming the electrode 191 and the second n-side electrode 192 .

Thereby, the semiconductor laser array 100 described above can be manufactured.

The laser module 700 according to this embodiment is connected to the semiconductor laser array 100 described above, the second p-side electrode block 763 connected to the second p-side electrode 182, and the first n-side electrode 191. The first n-side electrode block 762, the connector 765 electrically connecting the second p-side electrode block 763 and the first n-side electrode block 762, the first laminated structure 141 and the and a beam twister unit 725 arranged on the end surface (output end surface) side of the emitter section 130 of the laminated structure 142 .

A semiconductor laser processing apparatus 801 according to this embodiment includes the laser module 700 described above.

The single crystal substrate 110 according to the present embodiment is a compound semiconductor single crystal substrate used for manufacturing the semiconductor laser array 100 and is separated from each other by insulating single crystal portions 111 and 111 . A first conductive single crystal portion 121 and a second conductive single crystal portion 122 are provided. An insulating single crystal portion 111 , a first conductive single crystal portion 121 and a second conductive single crystal portion 122 are exposed on one main surface of the single crystal substrate 110 .

By using this single crystal substrate 110, the semiconductor laser array 100 described above can be manufactured.

[Modification]
The semiconductor laser array 100 according to the present embodiment has been described as a GaN-based semiconductor laser array that uses a GaN-based compound as a material and emits laser light 1 in a wavelength band of 405 nm or more and 450 nm or less. The wavelength band is not limited to this.

Even when the semiconductor laser array 100 employs a GaN-based semiconductor laser array, it may be a semiconductor laser array that emits laser light 1 in a wavelength band of 350 nm or more and 405 nm or less (blue-violet to ultraviolet), for example. It may also be a semiconductor laser array made of other III-V group semiconductor materials such as GaAs or InP.

In addition, in this embodiment, the plurality of emitter sections 130 are divided into two groups, and the emitter sections 130 of each group are arranged in two laminated structures 140 separated from each other. However, the plurality of emitter sections 130 may be divided into m (integer of 3 or more) groups and arranged in each of the m laminated structures 140 separated from each other. You can get the same effect as In that case, the single crystal substrate 110 has m−1 insulating single crystal portions 111 and m conductive single crystal portions 120 separated from each other by the m−1 insulating single crystal portions 111. .

Furthermore, in the manufacturing method of the semiconductor laser array 100, the insulating single crystal may be formed by inactivating the carriers of the conductive single crystal 540 by H ₂ ion implantation or the like instead of crystal growth.

[Example]
Examples are described below. In this example, the semiconductor laser array 100 was mounted on the laser module 700 according to the above-described embodiment, and a processing apparatus 801 having a plurality of the laser modules 700 mounted thereon was manufactured.

First, ten semiconductor laser arrays 100 that seemed to match the lock wavelength in Table 1 were prepared. Then, one semiconductor laser array 100 was mounted on one laser module 700, and ten laser modules 700 were prepared. Then, each semiconductor laser array 100 was caused to oscillate by internal resonance. Furthermore, five laser modules 700 having semiconductor laser arrays 100 matching the lock wavelength and gain wavelength were selected from the ten laser modules.

Then, the selected five laser modules 700 were arranged at predetermined positions of the housing 810 . After that, the optical axis of the laser module 700 was adjusted. Also, the cooling mechanism was activated to inject a current of 40 A into the semiconductor laser array 100 from a compact power supply device 830 with a capacity of 50 A, and the light output emitted from the external resonance mirror 328 was measured. As a result, in each semiconductor laser array 100, an optical output of approximately 330 W was obtained. Therefore, the insulation between the first conductive single-crystal portion 121 and the first laminated structure 141 and the second conductive single-crystal portion 122 and the first laminated structure 141 is maintained. It was found that the group of emitter sections 130 of the second laminated structure 141 and the group of emitter sections 130 of the second laminated structure 142 operate in series.

In addition, since the semiconductor laser array 100 was manufactured so that the crystallinity of the insulating single crystal portion 111 was low, the warpage of the semiconductor laser array 100 was small, and the light emitting positions of the emitter portions 130 were arranged substantially one-dimensionally. Specifically, the error of the light emission position of each emitter section 130 in the lamination direction of each layer constituting the laminated structure 140 was within ±3 μm.

In this way, the warpage is reduced and the light emitting positions of the emitter section 130 are arranged substantially one-dimensionally, so that the plurality of laser beams 1 emitted from the semiconductor laser array 100 do not spread unnecessarily. As a result, the laser light can be collected more efficiently in the processing device 801, and the quality of the laser light 329 emitted from the processing device 801 can be improved.

[Comparative example]
A comparative example will be described below. In this comparative example, a conventional semiconductor laser array 10 was mounted in a laser module, and a processing apparatus 800 was manufactured in which a plurality of such laser modules were mounted.

First, 10 conventional semiconductor laser arrays 10, which are semiconductor laser arrays 10 likely to match the lock wavelength in Table 1 and have light output characteristics similar to those of the semiconductor laser arrays 100 prepared in Examples, were prepared. Then, the prepared ten semiconductor laser arrays 10 were mounted one by one on a laser module. Then, laser oscillation was caused by internal resonance. Furthermore, five laser modules matching the lock wavelength and the gain wavelength were selected from the ten laser modules.

Then, the selected five laser modules were arranged at predetermined positions within the housing of the processing apparatus 800 . After that, the optical axis of the laser module was adjusted. Also, the cooling mechanism was activated to inject a current of 40 A from a large DC power source with a capacity of 80 A into the semiconductor laser array 10, and the optical output emitted from the external resonance mirror 328 was measured. As a result, an optical output of approximately 150 W was obtained in each semiconductor laser array 10 . On the other hand, when a current of 80 A was injected from the DC power supply into the semiconductor laser array 10 and the optical output emitted from the external resonant mirror 328 was measured, an optical output of about 330 W was obtained. From this, it was found that all the emitter sections 3 of the semiconductor laser array 10 were operating in parallel.

Also, the semiconductor laser array 10 had a relatively large warpage, and the emitter portions 3 were arranged in a U shape. Specifically, the error of the light emission position of each emitter section 3 in the lamination direction of each layer constituting the laminated structure 140 was about several 15 μm.

[Others, Comparison between Examples and Comparative Examples]
This embodiment uses a smaller power supply device 830 than the comparative example. Since the compact power supply device 830 has good voltage rise performance, the processing device 801 of the present embodiment can oscillate a higher output laser light steeply than the processing device 800 of the comparative example.

Therefore, this embodiment can prevent the occurrence of burrs and debris on the processing surface due to unstable output of laser light when processing an object to be processed, and can obtain laser light suitable for laser processing. can be done.

The semiconductor laser array, the method for manufacturing a semiconductor laser array, the laser module, the semiconductor laser processing apparatus, and the single crystal substrate of the present disclosure are suitable for a wavelength beam combining type semiconductor laser processing apparatus.

REFERENCE SIGNS LIST 1 laser beam 3 emitter section 10 semiconductor laser array 12 conductive single crystal substrate 14 laminated structure 15 light emitting layer 18 p-side electrode 19 n-side electrode 21 reflective film 22 reflective film 28 external resonant mirror 31 convex portion 83 emitter electrode portion 84 pad Electrode portion 99 Array body portion 100 Semiconductor laser array 110 Single crystal substrate 111 Insulating single crystal portion 120 Conductive single crystal portion 121 First conductive single crystal portion 122 Second conductive single crystal portion 130 Emitter portion 131 Projection 140 laminated structure 141 first laminated structure 142 second laminated structure 150 light emitting layer 160 first semiconductor layer 170 second semiconductor layer 180 p-side electrode 181 first p-side electrode 182 second p-side Electrode 183 Emitter electrode portion 184 Pad electrode portion 190 n-side electrode 191 first n-side electrode 192 second n-side electrode 211 reflective film 212 reflective film 320 mirror 325 beam twister unit 326 diffraction grating 327 laser light 328 external resonance mirror 329 Laser light 510 Base material 520 Insulating single crystal 530 Projection 540 Conductive single crystal 560 Multilayers 700-705 Laser module 725 Beam twister unit 761 First p-side electrode block 762 First n-side electrode block 763 Second p-side electrode block 764 second n-side electrode block 765 connector 771 upper metal block 772 lower metal block 773 water cooling mount 800 semiconductor laser processing device 801 semiconductor laser processing device 810 housing 820 mirror 830 power supply

Claims (6)

a single crystal substrate having an insulating single crystal portion and a first conductive single crystal portion and a second conductive single crystal portion separated from each other by the insulating single crystal portion;
a first laminated structure having an emitter portion for emitting a laser beam from an end face, and arranged on the surface of the first conductive single crystal portion and the surface of the second conductive single crystal portion; a second laminated structure;
a first p-side electrode and a second p-side electrode arranged on the first laminated structure and the second laminated structure, respectively;
a first n-side electrode and a second n-side electrode respectively arranged on the rear surface of the first conductive single crystal portion and the rear surface of the second conductive single crystal portion;
A semiconductor laser array. each of the first laminated structure and the second laminated structure has a plurality of the emitter sections,
the plurality of emitter portions of the first stacked structure are connected in parallel to the first p-side electrode;
The plurality of emitter portions of the second stacked structure are connected in parallel to the second p-side electrode,
A semiconductor laser array according to claim 1 . forming an insulating single crystal;
forming a protrusion on the surface of the insulating single crystal;
forming a conductive single crystal in a region including the protrusion on the surface of the insulating single crystal;
The surface of the conductive single crystal is processed to expose the conductive single crystal and the insulating single crystal, and the back surface of the insulating single crystal is processed to obtain an insulating layer made of the insulating single crystal. forming a single crystal portion and a first conductive single crystal portion and a second conductive single crystal portion made of the conductive single crystal and separated from each other by the insulating single crystal portion;
A first laminated structure and a second laminated structure having an emitter for emitting a laser beam from an end face are provided on the surface of the first conductive single crystal portion and the surface of the second conductive single crystal portion. forming;
forming a first p-side electrode and a second p-side electrode on respective surfaces of the first laminated structure and the second laminated structure;
forming a first n-side electrode and a second n-side electrode on the back surface of the first conductive single crystal portion and the back surface of the second conductive single crystal portion;
comprising
A method for manufacturing a semiconductor laser array. A semiconductor laser array according to claim 1 or 2;
a p-side electrode block connected to the second p-side electrode;
an n-side electrode block connected to the first n-side electrode;
a connector that electrically connects the p-side electrode block and the n-side electrode block;
a beam twister unit arranged on the end face side of the emitter section of the first laminated structure and the second laminated structure;
laser module with A semiconductor laser processing apparatus comprising the laser module according to claim 4 . A compound semiconductor single crystal substrate used for manufacturing a semiconductor laser array,
an insulating single crystal portion;
a first conductive single crystal portion and a second conductive single crystal portion separated from each other by the insulating single crystal portion;
with
The insulating single crystal portion, the first conductive single crystal portion, and the second conductive single crystal portion are exposed on one main surface of the single crystal substrate,
Single crystal substrate.

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