Method for manufacturing semiconductor laser device

Abstract

To form a resonator end face with high optical reflectivity with excellent flatness and perpendicularity to the c-plane.SOLUTION: A semiconductor laser body includes a base semiconductor portion and a compound semiconductor portion located on the base semiconductor portion and including a GaN-based semiconductor, the base semiconductor portion includes a first portion and a second portion extending in a thickness direction and having a threading dislocation density lower than that of the first portion, the compound semiconductor portion having an optical resonator including a pair of resonant end faces, at least one of the pair of resonant end faces is the m-plane or c-plane of the compound semiconductor portion, and a resonant length, which is the distance between the pair of resonant end faces, is 200 μm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to semiconductor lasers and the like. [Background technology]

[0002] For example, Patent Document 1 discloses a semiconductor laser chip including an optical resonator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2005-353702 Summary of the Invention

[0004] A semiconductor laser device according to the present disclosure comprises a base semiconductor portion and a compound semiconductor portion located on the base semiconductor portion and including a GaN-based semiconductor, the base semiconductor portion including a first portion and a second portion having a lower density of threading dislocations extending in a thickness direction than the first portion, the compound semiconductor portion having an optical resonator including a pair of resonant end faces, at least one of the pair of resonant end faces being an m-plane or a c-plane of the compound semiconductor portion, and a resonant length, which is the distance between the pair of resonant end faces, being 200 μm or less. [Brief explanation of the drawings]

[0005] [Figure 1] 1 is a perspective view showing a configuration of a semiconductor laser body according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing the configuration of an optical resonator. [Figure 3] FIG. 2 is a plan view showing the configuration of a compound semiconductor portion. [Figure 4] FIG. 2 is a plan view showing the configuration of a compound semiconductor portion. [Figure 5] FIG. 10 is a perspective view showing another configuration of the semiconductor laser body according to the embodiment. [Figure 6] 1 is a schematic diagram illustrating a configuration of a semiconductor laser element according to an embodiment of the present invention. [Figure 7] 3 is a flowchart illustrating an example of a method for manufacturing a semiconductor laser device according to the present embodiment. [Figure 8] 1 is a block diagram showing an example of a manufacturing apparatus for a semiconductor laser body according to an embodiment of the present invention. [Figure 9] 1 is a perspective view showing the configuration of a semiconductor laser body according to Example 1. FIG. [Figure 10] FIG. 2 is a plan view showing the configuration of a device layer. [Figure 11] 1 is a cross-sectional view showing the configuration of a semiconductor laser body according to Example 1. FIG. [Figure 12] 1 is a cross-sectional view showing the configuration of a semiconductor laser device according to Example 1. FIG. [Figure 13] 1 is a perspective view showing the configuration of a semiconductor laser device according to Example 1. FIG. [Figure 14] 4 is a cross-sectional view showing another configuration of the semiconductor laser device in accordance with the first embodiment. [Figure 15] 4 is a cross-sectional view showing another configuration of the semiconductor laser device in accordance with the first embodiment. [Figure 16] 4 is a cross-sectional view showing another configuration of the semiconductor laser device in accordance with the first embodiment. [Figure 17] 1 is a perspective view showing a configuration of a semiconductor laser substrate (semiconductor laser array) according to Example 1. FIG. [Figure 18] 10 is a perspective view showing another configuration of the semiconductor laser substrate according to the first embodiment. FIG. [Figure 19] 4 is a flowchart illustrating an example of a method for manufacturing a semiconductor laser device according to the first embodiment. [Figure 20] 20A to 20C are schematic cross-sectional views showing a method for manufacturing the semiconductor laser device of FIG. 19. [Figure 21] 5A to 5C are schematic cross-sectional views showing another example of the method for manufacturing the semiconductor laser device according to the first embodiment. [Figure 22] 5A to 5C are schematic cross-sectional views showing another example of the method for manufacturing the semiconductor laser device according to the first embodiment. [Figure 23] 3 is a cross-sectional view showing an example of lateral growth of an ELO semiconductor layer in Example 1. FIG. [Figure 24]10 is a flowchart showing another example of the method for manufacturing the semiconductor laser device according to the first embodiment. [Figure 25] 25A to 25C are schematic diagrams illustrating a method for manufacturing the semiconductor laser device of FIG. 24. [Figure 26] 10 is a flowchart showing another example of the method for manufacturing the semiconductor laser device according to the first embodiment. [Figure 27] 27A to 27C are schematic diagrams illustrating a method for manufacturing the semiconductor laser device of FIG. 26. [Figure 28] 10 is a flowchart showing another example of the method for manufacturing the semiconductor laser device according to the first embodiment. [Figure 29] 29A to 29C are schematic diagrams illustrating a method for manufacturing the semiconductor laser device of FIG. 28. [Figure 30] FIG. 10 is a perspective view showing the configuration of a semiconductor laser body according to Example 2. [Figure 31] FIG. 10 is a cross-sectional view showing the configuration of a semiconductor laser body according to Example 2. [Figure 32] FIG. 10 is a cross-sectional view showing the configuration of a semiconductor laser device according to Example 2. [Figure 33] 10 is a flowchart showing another example of the method for manufacturing the semiconductor laser device according to the second embodiment. [Figure 34] 34A to 34C are schematic diagrams illustrating a method for manufacturing the semiconductor laser device of FIG. 33. [Figure 35] FIG. 10 is a perspective view showing the configuration of a semiconductor laser device according to Example 2. [Figure 36] FIG. 10 is a perspective view showing the configuration of a semiconductor laser module according to a fourth embodiment. [Figure 37] FIG. 10 is a perspective view showing another configuration of the semiconductor laser module of Example 4. [Figure 38] FIG. 10 is a schematic diagram illustrating a configuration of an electronic device according to a fifth embodiment. [Figure 39] FIG. 10 is a perspective view showing the configuration of a semiconductor laser body according to Example 6. DETAILED DESCRIPTION OF THE INVENTION

[0006] [Semiconductor laser body] FIG. 1 is a perspective view showing the configuration of a semiconductor laser body according to this embodiment. FIG. 2 is a perspective view showing the configuration of an optical resonator. FIGS. 3 and 4 are plan views showing the configuration of a compound semiconductor section. FIG. 5 is a perspective view showing another configuration of a semiconductor laser body according to this embodiment. As shown in FIGS. 1 to 4, a semiconductor laser body 21 according to this embodiment includes a base semiconductor section 8 and a compound semiconductor section 9 located on the base semiconductor section 8 and including a nitride semiconductor (e.g., a GaN-based semiconductor). The base semiconductor section 8 may be a base semiconductor layer, or the compound semiconductor section 9 may be a compound semiconductor layer. The base semiconductor section 8 includes a first section B1 and a second section B2 having a threading dislocation density (threading dislocation density) extending in the thickness direction (Z direction) that is lower than that of the first section B1. The compound semiconductor section 9 has an optical resonator LK including a pair of resonant cavity facets F1 and F2.

[0007] The semiconductor laser body 21 may be configured such that at least one of the pair of cavity facets F1 and F2 is an m-plane or a c-plane of a compound semiconductor portion 9 including a nitride semiconductor, and the cavity length (cavity length) L1 between the pair of cavity facets (cavity facets) F1 and F2 is 200 μm or less. Each of the pair of cavity facets F1 and F2 may be an m-plane of the compound semiconductor portion 9, or each of the pair of cavity facets F1 and F2 may be a c-plane of the compound semiconductor portion 9. The m-plane is a plane parallel to the (1-100) plane of the nitride semiconductor, and the c-plane is a plane parallel to the (0001) plane of the nitride semiconductor.

[0008] The semiconductor laser body 21 may be configured such that at least one of the pair of cavity end faces F1 and F2 is included in the cleavage plane of the compound semiconductor portion 9, and the cavity length L1 is 200 μm or less. Each of the pair of cavity end faces F1 and F2 may be included in the cleavage plane of the compound semiconductor portion 9.

[0009] The semiconductor laser body 21 may be configured such that at least one of the pair of cavity facets F1 and F2 has an optical reflectivity of 98% or more and a cavity length L1 of 200 μm or less. The optical reflectivity of each of the pair of cavity facets F1 and F2 may be 98% or more, and a reflective film UF (e.g., a dielectric film) may be provided to cover the cavity facets F1 and F2, as shown in FIG. 3B.

[0010] In the semiconductor laser body 21, the optical reflectivity of at least one of the cavity facets F1 and F2 is high and the reflection loss is small, so stable laser oscillation is possible even with a short cavity length of 200 μm or less where the optical gain is small.

[0011] The base semiconductor portion 8 and the compound semiconductor portion 9 include, for example, nitride semiconductors. A nitride semiconductor can be expressed, for example, as AlxGayInzN (0≦x≦1; 0≦y≦1; 0≦z≦1; x+y+z=1), and specific examples include GaN-based semiconductors, AlN (aluminum nitride), InAlN (indium aluminum nitride), and InN (indium nitride). A GaN-based semiconductor is a semiconductor containing gallium atoms (Ga) and nitrogen atoms (N), and typical examples include GaN, AlGaN, AlGaInN, and InGaN. The base semiconductor portion 8 may be doped (e.g., n-type containing donors) or non-doped.

[0012] The base semiconductor portion 8, which includes a nitride semiconductor, can be formed by the ELO (Epitaxial Lateral Overgrowth) method. Hereinafter, a semiconductor layer formed by the ELO method may be referred to as an ELO semiconductor layer. In the ELO method, for example, the base semiconductor portion 8 is grown laterally on a template substrate having a mask portion (described later). This allows a low-defect portion (second portion B2) with a low threading dislocation density to be formed on the mask portion. Because fewer dislocations (defects) are inherited by the compound semiconductor portion 9 (e.g., a GaN-based semiconductor layer) on the second portion B2, the compound semiconductor portion 9 can have cavity facets F1 and F2 with excellent planarity and perpendicularity to the c-plane and high optical reflectivity.

[0013] The semiconductor laser body 21 may be provided with a first electrode E1 and a second electrode E2 for supplying current to the optical resonator LK. The first electrode E1 may be disposed so as to overlap with the optical resonator LK in a plan view seen in the thickness direction of the base semiconductor portion 8. Note that "two members overlap" means that at least a portion of one member overlaps the other member in a plan view seen in the thickness direction of each member (including a perspective plan view), and these members may or may not be in contact with each other.

[0014] 1, the first and second electrodes E1 and E2 are provided on the same side of the base semiconductor portion 8, and the first and second electrodes E1 and E2 do not overlap in a plan view, but this configuration (single-sided electrodes) is not limitative. As shown in FIG. 5, the first and second electrodes E1 and E2 may be provided on different sides of the base semiconductor portion 8, and the first and second electrodes E1 and E2 may overlap in a plan view (double-sided electrodes).

[0015] [Semiconductor laser device] 6 is a schematic diagram showing the configuration of a semiconductor laser element according to this embodiment. The semiconductor laser element 23 according to this embodiment includes one or more semiconductor laser bodies 21 and a support ST on which the one or more semiconductor laser bodies 21 are mounted. The semiconductor laser substrate 22 according to this embodiment includes a plurality of semiconductor laser bodies 21 and a support substrate SK on which the plurality of semiconductor laser bodies 21 are mounted. Hereinafter, the semiconductor laser body 21, the semiconductor laser element (a semiconductor laser element) 22, the semiconductor laser substrate (semiconductor laser array) 23, and a semiconductor laser module (described later) may be collectively referred to as a semiconductor laser device (a semiconductor laser device).

[0016] [Manufacturing of semiconductor laser devices] 7 is a flowchart showing an example of a method for manufacturing a semiconductor laser device according to this embodiment. In the manufacturing method shown in FIG. 7, after a step of preparing a template substrate (substrate for ELO growth) 7, a step of forming a first semiconductor layer, which will become a base semiconductor portion 8, using the ELO method is performed. This is followed by a step of forming a second semiconductor layer, which will become a compound semiconductor portion 9, and a step of forming a pair of cavity facets F1 and F2 in the second semiconductor layer.

[0017] 8 is a block diagram showing an example of an apparatus for manufacturing a semiconductor laser body according to this embodiment. The apparatus 70 for manufacturing a semiconductor laser body in Fig. 8 includes a semiconductor layer forming unit 72 that forms a first semiconductor layer and a second semiconductor layer on a template substrate 7, a semiconductor layer processing unit 73 that forms a pair of cavity facets in the second semiconductor layer, and a control unit (controller) 74 that controls the semiconductor layer forming unit 72 and the semiconductor layer processing unit 73.

[0018] The semiconductor layer forming unit 72 may include an MOCVD (Metal Organic Chemical Vapor Deposition) device, and the control unit 74 may include a processor and a memory. The control unit 74 may be configured to control the semiconductor layer forming unit 72 and the semiconductor layer processing unit 73 by executing a program stored in, for example, an internal memory, a communication device capable of communication, or an accessible network. The above program and a recording medium on which the above program is stored are also included in this embodiment.

[0019] Example 1 (composition) FIG. 9 is a perspective view showing the configuration of a semiconductor laser body according to Example 1. FIG. 10 is a plan view showing the configuration of a device layer. FIG. 11 is a cross-sectional view showing the configuration of a semiconductor laser body according to Example 1. As shown in FIGS. 9 to 11, the semiconductor laser body 21 according to Example 1 includes a base semiconductor portion 8, a compound semiconductor portion 9 located on the base semiconductor portion 8, a first electrode E1 which is an anode, and a second electrode E2 which is a cathode. The semiconductor laser body 21 can also be called a semiconductor laser chip.

[0020] The base semiconductor portion 8 and the compound semiconductor portion 9 are nitride semiconductor layers (for example, GaN-based semiconductor layers), and the base semiconductor portion 8 is an n-type semiconductor layer having donors. In FIG. 9 and other figures, the <11-20> direction of the base semiconductor portion 8 is the X direction, the <1-100> direction is the Y direction, and <0001> The direction is the Z direction (thickness direction).

[0021] The base semiconductor portion 8 is a free-standing layer without a support material. The base semiconductor portion 8 includes a first portion B1 including threading dislocations KD extending in the Z direction, and a second portion B2 and a third portion B3 having a threading dislocation density lower than that of the first portion B1. The second portion B2, the first portion B, and the third portion B3 are arranged in this order in the X direction, and the first portion B1 is located between the second portion B2 and the third portion B3. The first portion B1 is a portion that was located above the opening of the mask layer 6 when the base semiconductor portion 8 was formed by the ELO method (described later). The first portion B1 may be a dislocation inheritance portion. The threading dislocation densities of the second portion B2 and the third portion B3 are 1 / 5 or less (for example, 5×10) of the threading dislocation density of the first portion B1. 6 / cm 2 Since the base semiconductor portion 8 is a free-standing layer, in the semiconductor laser body 21, the back surface (for example, the −c plane) of the base semiconductor portion 8 may be exposed.

[0022] The compound semiconductor section 9 is formed by forming, in this order, an n-type semiconductor layer 9N having a donor, an active layer 9K, and a p-type semiconductor layer 9P having an acceptor. The n-type semiconductor layer 9N is formed by forming, in this order, a first contact layer 9A, a first cladding layer 9B, and a first optical guide layer 9C. The p-type semiconductor layer 9P may be formed by forming, in this order, a second optical guide layer 9D, an electron blocking layer 9E, a second cladding layer 9F, and a second contact layer 9G. A first electrode E1 (anode) may be formed on the second contact layer 9G.

[0023] The second electrode E2 may be provided on the same side of the base semiconductor portion 8 as the first electrode E1. The second electrode E2 is in contact with the base semiconductor portion 8, and the first and second electrodes E1 and E2 do not overlap in a plan view. Specifically, the base semiconductor portion 8 may be wider in the X direction than the compound semiconductor portion 9, and the second electrode E2 may be formed on an exposed portion where the compound semiconductor portion 9 is not formed. For example, a portion of the compound semiconductor portion 9 may be recessed by etching or the like to expose the base semiconductor portion 8, and the second electrode E2 may be provided so as to contact the base semiconductor portion 8. Alternatively, a portion of the compound semiconductor portion 9 may be recessed by etching or the like to expose the first contact layer 9A in the compound semiconductor portion 9, and the second electrode E2 may be provided so as to contact the first contact layer 9A.

[0024] The compound semiconductor portion 9 has an optical resonator LK including a pair of cavity facets F1 and F2, and a cavity length L1, which is the distance between the pair of cavity facets F1 and F2, is 200 μm or less. The cavity length L1 may be 10 μm or more and 200 μm or less. Each of the cavity facets F1 and F2 may be an m-plane of the compound semiconductor portion 9 and may be included in a cleavage plane of the compound semiconductor portion 9. That is, each of the cavity facets F1 and F2 can be formed by m-plane cleavage of the compound semiconductor portion 9, which is a nitride semiconductor layer (e.g., a GaN-based semiconductor layer). At least one of the base semiconductor portion 8 and the compound semiconductor portion 9 may have scribe marks for cleavage (marks of the formation of cleavage start points).

[0025] Each of the cavity facets F1 and F2 is covered with a reflective film UF (e.g., a dielectric film), and the optical reflectivity of the cavity facet F1 on the light-emitting surface side is 98% or higher. The optical reflectivity of the cavity facet F1 may be 98.00% or higher and 99.99% or lower. The optical reflectivity of the cavity facet F2 on the light-reflecting surface side is higher than that of the cavity facet F1. Although not shown in FIG. 9 , the reflective film UF can be formed on the entire cleavage plane (m-plane) of the base semiconductor portion 8 and the compound semiconductor portion 9.

[0026] The first electrode E1 overlaps the optical resonator LK in plan view, and also overlaps the second portion B2 of the base semiconductor portion 8. The first electrode E1 has a shape whose longitudinal direction is the direction of the resonance length (Y direction), and the length of the first electrode E1 in the Y direction is shorter than the resonance length L1. Therefore, the first electrode E1 does not interfere with cleavage of the compound semiconductor portion 9.

[0027] The optical resonator LK includes a portion (portion overlapping with the first electrode E1 in plan view) of each of the n-type semiconductor layer 9N, the active layer 9K, and the p-type semiconductor layer 9P. For example, the optical resonator LK includes a portion (portion overlapping with the first electrode E1 in plan view) of each of the first cladding layer 9B, the first optical guiding layer 9C, the active layer 9K, the second optical guiding layer 9D, the electron blocking layer 9E, and the second cladding layer 9F.

[0028] In the optical resonator LK, the refractive index (optical refractive index) decreases in the order of the active layer 9K, the first optical guide layer 9C, and the first cladding layer 9B, and also decreases in the order of the active layer 9K, the second optical guide layer 9D, and the second cladding layer 9F. Therefore, light generated by the combination of holes supplied from the first electrode E1 and electrons supplied from the second electrode E2 in the active layer 9K is confined within the optical resonator LK (particularly the active layer 9K), and laser oscillation occurs due to stimulated emission and feedback in the active layer 9K. The laser light generated by laser oscillation is emitted from a light emission region EA of the resonator end facet F1 on the emission surface side.

[0029] Because the cavity facets F1 and F2 are formed by m-plane cleavage, they have excellent flatness and perpendicularity to the c-plane (parallelism of the cavity facets F1 and F2), resulting in high optical reflectivity. This reduces reflection loss, enabling stable laser oscillation even at short cavity lengths of 200 μm or less, where optical gain becomes small. Because the cavity facets F1 and F2 are formed on the second portion B2, which is a low-dislocation region, the cleavage facets have excellent flatness, resulting in high optical reflectivity.

[0030] The compound semiconductor portion 9 includes a ridge portion RJ (ridge portion) that overlaps the first electrode E1 in a planar view, and the ridge portion RJ may include a second cladding layer 9F and a second contact layer 9G. The ridge portion RJ has a shape with its longitudinal direction in the Y direction, and an insulating film DF may be provided to cover the side surfaces of the ridge portion RJ. Both ends of the first electrode E1 in the X direction may overlap with the insulating film DF in a planar view. The refractive index of the insulating film DF is smaller than the refractive indexes of the second optical guide layer 9D and the second cladding layer 9F. By providing the ridge portion RJ and the insulating film DF, the current path between the first electrode E1 and the base semiconductor portion 8 is narrowed on the anode side, allowing efficient light emission within the resonator LK.

[0031] The ridge portion RJ overlaps with the second portion B2 (low dislocation portion) of the base semiconductor portion 8 in plan view, but does not overlap with the first portion B1. In this way, the current path from the first electrode E1 through the compound semiconductor portion 9 and the base semiconductor portion 8 to the second electrode E2 is formed in the portion overlapping with the second portion B2 in plan view (a portion with few threading dislocations), and the light emission efficiency of the active layer 9K is improved. This is because threading dislocations act as non-radiative recombination centers. Furthermore, because the second electrode E2 overlaps with the third portion B3 (low dislocation portion) of the base semiconductor portion 8 in plan view, the efficiency of electron injection from the second electrode E2 to the base semiconductor portion 8 is improved.

[0032] In the first embodiment, the sum T1 of the thickness of the base semiconductor portion 8 and the thickness of the compound semiconductor portion 9 can be set to 5 μm or more and 50 μm or less. If this sum T1 of thicknesses is too large, it becomes difficult to cleave the base semiconductor portion 8 so that the resonance length is 200 μm or less. The ratio of the resonance length L1 to the thickness of the second portion B2 of the base semiconductor portion 8 can be set to 1 to 20. Furthermore, the direction perpendicular to the direction of the resonance length L1 is defined as the first direction (X direction), and the size of the second portion B2 in the X direction is defined as the width W2 of the second portion B2. The ratio of the resonance length L1 to the width W2 of the second portion B2 can be set to 1 to 10. The size of the first portion B1 in the X direction is defined as the width W1 of the first portion B1. The ratio of the resonance length L1 to the width W1 of the first portion B1 can be set to 1 to 200.

[0033] The base semiconductor portion 8 includes a base end face 8T (cleavage plane) that is flush with the cavity end face F1, and the density of dislocations (dislocations measured by CL (Cathode Luminescence) at the cleavage plane, primarily basal plane dislocations) at the base end face 8T may be equal to or greater than the threading dislocation density of the second portion B2. Furthermore, the surface roughness of at least one of the pair of cavity end faces F1 and F2 (for example, the cavity end face F2 on the reflecting surface side) may be smaller than the surface roughness of the side face 9S (see FIG. 10 ), which is the a-plane of the compound semiconductor portion 9. The a-plane is a plane parallel to the (11-20) plane of the nitride semiconductor layer.

[0034] In the first embodiment, for example, a power of 1 mW or more and 200 mW or less is supplied between the first and second electrodes E1 and E2, and a semiconductor laser with high efficiency and low output power can be realized due to a short cavity length of 200 μm or less.

[0035] The lower surface (rear surface) of the base semiconductor portion 8 may include a first region 8C and a second region 8S. The first region 8C may have a surface roughness greater than that of the second region 8S. At least one of convex portions and concave portions may be formed in the first region 8C. For example, a plurality of randomly shaped protrusions or a plurality of randomly shaped concave portions may be formed. The first region 8C may be a region corresponding to the first portion B1 (e.g., a central region), and the second region 8S may be a region corresponding to the second portion B2 (e.g., a side region between the central region and the edge). The first region 8C may be formed so as not to overlap with the ridge portion RJ in a planar view. The first region 8C may improve heat dissipation. A dielectric film made of the same material as the reflector film UF may be formed on at least a portion of the first region 8C.

[0036] 12 is a cross-sectional view showing the configuration of a semiconductor laser device according to Example 1. The semiconductor laser device 23 includes a semiconductor laser body 21 including a base semiconductor portion 8 and a compound semiconductor portion 9, and a support ST that holds the semiconductor laser body 21. Examples of materials for the support ST include Si, SiC, and AlN. The support ST is disposed such that the compound semiconductor portion 9 and the first and second electrodes E1 and E2 are located between the support ST and the base semiconductor portion 8.

[0037] The support ST includes conductive first and second pad portions P1 and P2, with the first electrode E1 connected to the first pad portion P1 via a first bonding portion A1 and the second electrode E2 connected to the second pad portion P2 via a second bonding portion A2. The second bonding portion A2 is thicker than the first bonding portion A1, and the difference in thickness between the first and second bonding portions A1 and A2 is equal to or greater than the thickness of the compound semiconductor portion 9. This allows connection between the first and second electrodes E1 and E2 and the first and second pad portions P1 and P2, which are located on the same plane. In other words, the semiconductor laser element 23 functions as a COS (chip on submount).

[0038] FIG. 13 is a perspective view showing the configuration of a semiconductor laser device according to Example 1. As shown in FIG. 13, the semiconductor laser device 23 includes a semiconductor laser body 21 and a support member ST. The support member ST has two wide portions SH having a width greater than the resonant cavity length of the semiconductor laser body 21 and a mounting portion SB located between the two wide portions SH and having a width smaller than the resonant cavity length. The semiconductor laser body 21 is located above the mounting portion SB so that the width direction (Y direction) of the mounting portion SB coincides with the direction of the resonant cavity length. In plan view, a pair of resonant cavity end faces F1 and F2 protrude from the mounting portion SB. In other words, the mounting portion SB is formed between two cutout portions C1 and C2 facing each other in the direction defining the resonant cavity length (Y direction). The resonant cavity end face F1 is located on the cutout portion C1, and the resonant cavity end face F2 is located on the cutout portion C2. The cutout portions C1 and C2 may have, for example, a rectangular shape in plan view in the Z direction. By providing the notches C1 and C2 in the support ST and positioning the cavity end face F1 so that it extends beyond the mounting portion SB, the problem of the laser light emitted from the cavity end face F1 being blocked by the light-shielding support ST is eliminated.

[0039] The support ST may include a T-shaped first pad portion P1 and a second pad portion P2. The first pad portion P1 includes a mounting portion J1 located on the wide portion SH and having a length in the Y direction greater than the resonance length L1, and a contact portion Q1 located on the mounting portion SB and having a length in the Y direction less than the resonance length L1. The second pad portion P2 includes a mounting portion J2 located on the wide portion SH and having a length in the Y direction greater than the resonance length L1, and a contact portion Q2 located on the mounting portion SB and having a length in the Y direction less than the resonance length L1. The contact portions Q1 and Q2 may be aligned in the X direction on the upper surface of the mounting portion SB, with a first bonding portion A1 formed on the contact portion Q1 and a second bonding portion A2 formed on the contact portion Q2. The first bonding portion A1 contacts the first electrode E1 of the semiconductor laser body 21, and the second bonding portion A2 contacts the second electrode E2 of the semiconductor laser body 21. The first and second bonding portions A1 and A2 may be made of solder such as AuSi or AuSn.

[0040] The cavity facets F1 and F2 of the semiconductor laser body 21 are covered with a reflective film UF, but a dielectric film SF made of the same material as the reflective film UF may be formed on one of the side surfaces of the support ST that is parallel to the cavity facets F1 and F2 (for example, the side surface of the mounting portion SB).

[0041] Fig. 14 is a cross-sectional view showing another configuration of the semiconductor laser device in accordance with Example 1. In Fig. 13, the cutout portions C1 and C2 are rectangular in plan view in the Z direction, but this is not limiting. As shown in Fig. 14, the cutout portions C1 and C2 may have a trapezoidal shape with the shorter side on the side of the mounting portion SB in plan view in the Z direction.

[0042] 15 and 16 are cross-sectional views showing other configurations of the semiconductor laser element according to Example 1. In the semiconductor laser element 23 of FIG. 15, a plurality of semiconductor laser bodies 21 may be arranged on a support ST in a direction (X direction) perpendicular to the direction defining the cavity length so that the directions of the cavity lengths are aligned, and first and second pad portions P1 and P2 may be provided corresponding to each semiconductor laser body 21. As shown in FIG. 16, a sensor device (electronic device) such as a photodiode PD may be provided in a notch C1 of the support ST. This allows the photodiode PD to detect light from the semiconductor laser body 21, thereby enabling feedback control of the emission intensity of the semiconductor laser body 21.

[0043] 17 is a perspective view showing the configuration of a semiconductor laser substrate (semiconductor laser array) according to Example 1. The semiconductor laser substrate 22 includes a support substrate SK and a plurality of semiconductor laser bodies 21. In the semiconductor laser substrate 22, the plurality of semiconductor laser bodies 21 may be arranged in a matrix on the support substrate SK in a direction defining the resonance length (Y direction) and a direction perpendicular thereto (X direction) so that the resonance lengths are aligned. First and second pad portions P1 and P2 and first and second bonding portions A1 and A2 may be provided corresponding to each semiconductor laser body 21.

[0044] The support substrate SK can be formed, for example, by providing a matrix of multiple recesses HL (rectangular in plan view) in a Si substrate, SiC substrate, etc., and providing multiple first pad portions P1, multiple second pad portions P2, multiple first bonding portions A1, and multiple second bonding portions A2 in the non-recessed portions.

[0045] Fig. 18 is a perspective view showing another configuration of the semiconductor laser substrate according to the first embodiment. A two-dimensionally arranged semiconductor laser substrate in which a plurality of semiconductor laser bodies are arranged in a matrix as shown in Fig. 16 can be divided horizontally (divided into rows extending in the X direction) to form a one-dimensionally arranged (bar-shaped) semiconductor laser substrate as shown in Fig. 18. The one-dimensionally arranged type facilitates the formation of a reflective film UF on the pair of cavity facets F1 and F2.

[0046] (Manufacturing method) Fig. 19 is a flowchart illustrating an example of a method for manufacturing the semiconductor laser device according to Example 1. Fig. 20 is a schematic cross-sectional view illustrating a method for manufacturing the semiconductor laser device of Fig. 19. 19 and 20 includes the steps of: preparing a template substrate 7 including a base substrate UK and a mask layer 6; forming a strip-shaped (longitudinal, ridge-shaped) first semiconductor layer S1 (and a third semiconductor layer S3) by ELO (described later) that will become the base semiconductor portion 8; forming a second semiconductor layer S2 (and a fourth semiconductor layer S4) that will become the compound semiconductor portion 9; forming a stacked body LB that has the first semiconductor layer S1, the second semiconductor layer S2 including a ridge portion, and a first electrode E1 and a second electrode E2; bonding the stacked body LB to a support substrate SK and separating the first semiconductor layer S1 from the template substrate 7; cleaving the stacked body LB on the support substrate SK to form a pair of resonant cavity facets F1 and F2 (an optical resonator LK including the pair of resonant cavity facets F1 and F2); forming a reflector film UF on each of the pair of resonant cavity facets F1 and F2; and dividing the support substrate SK into a plurality of support bodies ST.

[0047] After the laminate LB is formed, the mask layer 6 is etched away, and the first and second bonding portions A1 and A2 (e.g., solder) of the support substrate SK are heated and melted while the laminate LB is bonded to the support substrate SK. This breaks the bonded portion (downward protruding portion) on the back surface of the first semiconductor layer S1 with the base substrate UK, and the first semiconductor layer S1 is separated from the template substrate 7. Note that because the first semiconductor layer S1 and the base substrate UK were bonded at their interface, after they are separated, the interface-adjacent portion of the first semiconductor layer S1 may be attached to the base substrate UK side, as shown in FIG. 20, or may be attached to the first semiconductor layer S1 side. Furthermore, the interface-adjacent portion of the base substrate UK may remain on the base substrate UK side, or may be attached to the first semiconductor layer S1 side.

[0048] Thereafter, the laminate LB is cleaved on the support substrate SK (m-plane cleavage of the first and second semiconductor layers S1 and S2, which are nitride semiconductor layers) to form a pair of cavity facets F1 and F2. Before cleaving, the laminate LB may be scribed (for example, by forming scribe grooves that serve as cleavage initiation points). This results in a two-dimensionally arranged semiconductor laser substrate (see FIG. 17). Next, the two-dimensionally arranged semiconductor laser substrate is divided into rows to form one-dimensionally arranged (rod-shaped) semiconductor laser substrates 22 (see FIG. 18). Next, a reflecting mirror film UF is formed on the cavity facets F1 and F2 of the one-dimensionally arranged semiconductor laser substrate 22. Thereafter, the support substrate SK is divided into a plurality of support members ST, and one or more semiconductor laser bodies 21 are held by each support member ST, thereby forming a plurality of junction-down semiconductor laser elements 23 (see FIGS. 13 to 15). The reflector film UF (e.g., a dielectric film) may be formed not only on the cleavage planes (m-planes) of the base semiconductor portion 8 and the compound semiconductor portion 9, but also on the side surfaces of the support ST that are parallel to the cavity end faces F1 and F2 (including the side surfaces of the mounting portion SB).

[0049] 21 and 22 are schematic cross-sectional views showing another example of the method for manufacturing the semiconductor laser device according to Example 1. As shown in Fig. 21, it is also possible to stack a plurality of one-dimensionally arranged semiconductor laser substrates 22 (see Fig. 18) in the Z direction so that the back surfaces of the base semiconductor portions 8 face each other, and simultaneously form a reflector film UF on the cavity end faces F1 and F2 of each semiconductor laser substrate 22. Furthermore, as shown in Fig. 22, when dividing the support substrate SK into a plurality of support bodies ST, the support bodies ST can hold a plurality of semiconductor laser bodies 21, thereby forming the semiconductor laser body 21 shown in Fig. 15.

[0050] (Base semiconductor part) FIG. 23 is a cross-sectional view showing an example of lateral overgrowth of an ELO semiconductor layer in Example 1. As shown in FIG. 23, the base substrate UK includes a main substrate 1 and an underlayer 4 on the main substrate 1, and the seed layer 3 of the underlayer 4 is exposed through an opening K in a mask portion 5. In the ELO method, an initial growth layer SL is first formed on the seed layer 3, and then the first semiconductor layer S1 can be grown laterally from the initial growth layer SL. The initial growth layer SL is the starting point for the lateral overgrowth of the first semiconductor layer S1 and is part of the first portion B1 of the base semiconductor portion 8. By appropriately controlling the ELO film formation conditions, it is possible to control the growth of the first semiconductor layer S1 to either the Z direction (c-axis direction) or the X direction (a-axis direction).

[0051] Here, it is preferable to stop the deposition of the initial growth layer SL just before the edge of the initial growth layer SL rises onto the upper surface of the mask portion 5 (the stage where it touches the upper end of the side surface of the mask portion 5) or just after it rises onto the upper surface of the mask portion 5 (i.e., at this timing, the ELO deposition conditions are switched from the c-axis deposition conditions to the a-axis deposition conditions). In this way, lateral deposition is performed from a state in which the initial growth layer SL slightly protrudes from the mask portion 5, so that material is less likely to be consumed in the thickness direction growth of the first semiconductor layer S1, and the first semiconductor layer S1 can be grown laterally at a high speed. The initial growth layer SL may be formed to a thickness of, for example, 2.0 μm or more and 3.0 μm or less.

[0052] In Example 1, the first semiconductor layer S1, which is the basis of the base semiconductor portion 8, was an n-type GaN layer, and Si-doped GaN (gallium nitride) was deposited on the template substrate 7 by ELO using an MOCVD apparatus. Examples of ELO deposition conditions include a substrate temperature of 1120°C, growth pressure of 50 kPa, TMG (trimethylgallium) at 22 sccm, NH3 at 15 slm, and V / III = 6000 (the ratio of the amount of Group V source material supplied to the amount of Group III source material supplied). The lateral growth of the first and third semiconductor layers S1 and S3, which grew laterally on both sides of the mask portion 5, was stopped before they merged.

[0053] The width of the mask portion 5 was 50 μm, the width of the opening K was 5 μm, the lateral width of the first semiconductor layer S1 was 53 μm, the width (size in the X direction) of the low-defect portions B2 and B3 was 24 μm, and the thickness of the first semiconductor layer S1 was 5 μm. The aspect ratio of the first semiconductor layer S1 was 53 μm / 5 μm=10.6, which was a high aspect ratio.

[0054] A heterogeneous substrate having a lattice constant different from that of the nitride semiconductor can be used for the main substrate 1 in Fig. 23. Examples of heterogeneous substrates include single-crystal silicon (Si) substrates, sapphire (Al2O3) substrates, and silicon carbide (SiC) substrates. The plane orientation of the main substrate 1 is, for example, the (111) plane of a silicon substrate, the (0001) plane of a sapphire substrate, or the 6H-SiC (0001) plane of a SiC substrate.

[0055] As the underlayer 4 in FIG. 23 , a buffer layer 2 and a seed layer 3 can be provided in this order from the main substrate 1 side. For example, if a silicon substrate is used for the main substrate 1 and a GaN-based semiconductor is used for the seed layer 3, the two (the main substrate and the seed layer) will melt together. Therefore, providing a buffer layer 2 including at least one of an AlN layer and a SiC (silicon carbide) layer reduces melting. The buffer layer 2 may have at least one of the effects of increasing the crystallinity of the seed layer 3 and alleviating the internal stress of the first semiconductor layer S1. If a main substrate 1 that does not melt together with the seed layer 3 is used, a configuration without providing the buffer layer 2 is also possible. Note that the configuration in FIG. 23 is not limited to one in which the seed layer 3 overlaps the entire mask portion 5. Since the seed layer 3 only needs to be exposed from the opening K, the seed layer 3 may be formed locally so as not to overlap part or all of the mask portion 5.

[0056] The openings K in the mask layer 6 function as growth initiation holes that expose the seed layer 3 and initiate the growth of the first semiconductor layer S1, and the mask portions 5 of the mask layer 6 function as selective growth masks that cause the first semiconductor layer S1 to grow laterally. The mask layer 6 may be a mask pattern that includes the mask portions 5 and the openings K.

[0057] The mask layer 6 may be, for example, a single layer film including one of a silicon oxide film (SiOx), a titanium nitride film (TiN, etc.), a silicon nitride film (SiNx), a silicon oxynitride film (SiON), and a metal film having a high melting point (e.g., 1000°C or higher), or a laminated film including at least two of these.

[0058] For example, a silicon oxide film having a thickness of about 100 nm to 4 μm (preferably about 150 nm to 2 μm) is formed on the entire surface of the underlayer 4 using a sputtering method, and a resist is applied to the entire surface of the silicon oxide film. The resist is then patterned using a photolithography method to form a resist with a plurality of stripe-shaped openings. Then, a wet etchant such as hydrofluoric acid (HF) or buffered hydrofluoric acid (BHF) is used to remove portions of the silicon oxide film to form the plurality of openings K, and the resist is then removed by organic cleaning to form the mask layer 6.

[0059] The openings K have a longitudinal shape (slit shape) and are periodically arranged in the a-axis direction (X direction) of the first semiconductor layer S1. The width of the openings K is approximately 0.1 μm to 20 μm. The smaller the width of each opening, the fewer the number of threading dislocations propagating from each opening to the first semiconductor layer S1. In addition, the width (size in the X direction) of the low-defect portions B2 and B3 can be increased.

[0060] While silicon oxide films decompose and evaporate in minute amounts during the formation of the ELO semiconductor layer and can become incorporated into the ELO semiconductor layer, silicon nitride films and silicon oxynitride films have the advantage of being less susceptible to decomposition and evaporation at high temperatures.

[0061] Therefore, the mask layer 6 may be a single layer film of a silicon nitride film or a silicon oxynitride film, or may be a laminated film in which a silicon oxide film and a silicon nitride film are formed in this order on the underlayer 4, or may be a laminated film in which a silicon nitride film and a silicon oxide film are formed in this order on the underlayer 4, or may be a laminated film in which a silicon nitride film, a silicon oxide film and a silicon nitride film are formed in this order on the underlayer.

[0062] When the first semiconductor layer S1 or the base semiconductor portion 8 is formed using the ELO method, a template substrate including an underlying substrate UK and a mask pattern on the underlying substrate UK may be used. The template substrate may have a growth-inhibiting region (e.g., a region that inhibits crystal growth in the Z direction) corresponding to the mask portion 5, and a seed region corresponding to the opening K. For example, the growth-inhibiting region and the seed region may be formed on the underlying substrate UK, and the first semiconductor layer S1 or the base semiconductor portion 8 may be formed on the growth-inhibiting region and the seed region using the ELO method.

[0063] (Compound Semiconductor Department, etc.) The compound semiconductor section 9 can be formed using, for example, an MOCVD apparatus. The first contact layer 9A can be, for example, an n-type GaN layer, the first cladding layer 9B can be, for example, an n-type AlGaN layer, the first optical guide layer 9C can be, for example, an n-type GaN layer, and the active layer 9K can be, for example, an InGaN layer, forming a multi-quantum well (MQW) structure. The electron blocking layer 9E can be, for example, a p-type AlGaN layer, the second optical guide layer 9D can be, for example, a p-type GaN layer, the second cladding layer 9F can be, for example, a p-type AlGaN layer, and the second contact layer 9G can be, for example, a p-type GaN layer. In the compound semiconductor section 9, the second optical guide layer 9D and the electron blocking layer 9E may be arranged interchangeably in the p-type semiconductor layer 9P. For example, the p-type semiconductor layer 9P can be formed by forming the electron blocking layer 9E, the second optical guide layer 9D, the second cladding layer 9F, and the second contact layer 9G in this order.

[0064] The thickness of each layer of the semiconductor laser body 21 can be expressed as base semiconductor portion 8>first cladding layer 9B>first optical guide layer 9C>active layer 9K, and base semiconductor portion 8>second cladding layer 9F>second optical guide layer 9D>active layer 9K. Furthermore, the refractive index of each layer of the compound semiconductor portion 9 (refractive index of light generated in the active layer 9K) can be expressed as first cladding layer 9B<first optical guide layer 9C<active layer 9K, and insulating film DF<second cladding layer 9F<second optical guide layer 9D<active layer 9K.

[0065] The first and second electrodes E1 and E2 and the first and second pads P1 and P2 can be formed of a single-layer or multi-layer film containing at least one of a metal film (which may be an alloy film) containing at least one of Ni, Rh, Pd, Cr, Au, W, Pt, Ti, and Al, and a conductive oxide film containing at least one of Zn, In, and Sn. The insulating film DF covering the ridge portion RJ can be formed of a single-layer or multi-layer film containing, for example, an oxide or nitride of Si, Al, Zr, Ti, Nb, or Ta.

[0066] The first semiconductor layer S1 (ELO semiconductor layer) that will become the base semiconductor portion 8 and the second semiconductor layer S2 that will become the compound semiconductor portion 9 can be successively deposited in the same deposition apparatus (for example, an MOCVD apparatus). Alternatively, the intermediate substrate on which the first semiconductor layer S1 has been deposited can be temporarily removed from the deposition apparatus, and the second semiconductor layer S2 can be deposited on the first semiconductor layer S1 using a different apparatus. In this case, the second semiconductor layer S2 may be formed after an n-type GaN layer (for example, with a thickness of about 0.1 μm to 3 μm) that will serve as a buffer during regrowth has been formed on the first semiconductor layer S1.

[0067] The reflective film UF covering the resonator facets F1 and F2 can be made of dielectric materials such as SiO2, Al2O3, AlN, AlON, Nb2O5, Ta2O5, and ZrO2. The reflective film UF may also be a multilayer film. The reflective film UF can be formed by electron beam evaporation, electron cyclotron resonance sputtering, chemical vapor deposition, etc.

[0068] (Variation) Fig. 24 is a flowchart showing another example of the method for manufacturing the semiconductor laser device according to Example 1. Fig. 25 is a schematic diagram showing the method for manufacturing the semiconductor laser device of Fig. 24. In the manufacturing method shown in Figs. 24 and 25, after a step of scribing the laminate LB on the template substrate 7 (for example, forming a crack SC at the initiation point of m-plane cleavage), the laminate LB is bonded to a support substrate SK. This separates the first semiconductor layer S1 from the template substrate 7, and cleaves the laminate LB to form a pair of cavity facets F1 and F2.

[0069] Fig. 26 is a flowchart showing another example of the method for manufacturing the semiconductor laser device according to Example 1. Fig. 27 is a schematic diagram showing the method for manufacturing the semiconductor laser device of Fig. 26. The manufacturing method shown in Fig. 26 and Fig. 27 includes the steps of transferring the laminate LB from the template substrate 7 to an adhesive first tape TF, cleaving the laminate LB on the first tape TF to form a pair of cavity facets, transferring the semiconductor laser body 21 including the pair of cavity facets F1 and F2 to a heat-resistant second tape TS, bonding the semiconductor laser body 21 on the second tape TS to a support substrate SK, forming a reflector film UF on the pair of cavity facets F1 and F2, and dividing the support substrate SK.

[0070] After the laminate LB is formed, the mask layer 6 is etched away, and the laminate LB is transferred to an adhesive first tape TF, thereby separating the first semiconductor layer S1 from the template substrate 7. The laminate LB is then cleaved (m-plane cleavage) on the first tape TF to form a pair of cavity facets F1 and F2. The cavity length (cavity length) can be, but is not limited to, 200 μm or less (the cavity length may be 200 μm or more). Alternatively, the laminate LB may be scribed (to form a starting point for m-plane cleavage) and then cleaved to form the pair of cavity facets F1 and F2. Alternatively, the laminate LB may be scribed to release internal stress and allow the cleavage to proceed naturally. Next, the semiconductor laser body 21 is temporarily transferred to the second tape TS, and the semiconductor laser body 21 on the second tape TS is bonded to a support substrate SK. This results in a two-dimensionally arranged semiconductor laser substrate (see FIG. 17). Next, the two-dimensionally arranged semiconductor laser substrate is divided into rows to form one-dimensionally arranged (bar-shaped) semiconductor laser substrates 22 (see FIG. 18). Next, a reflecting mirror film UF is formed on the cavity facets F1 and F2 of the one-dimensionally arranged semiconductor laser substrate 22. Thereafter, the support substrate SK is divided into a plurality of support members ST, and one or more semiconductor laser bodies 21 are held on each support member ST to form a plurality of semiconductor laser elements 23 (see FIGS. 13 to 15). Each semiconductor laser body 21 is held on the support member ST in a junction-down format (a mounting format in which the ridge portion is located on the support member ST side).

[0071] The base material of the first tape TF can be made of a material such as PET (polyethylene terephthalate). The base material of the second tape TS can be made of a material such as polyimide. The base materials of the first and second tapes TF and TS can be made of the same material or different materials.

[0072] 26, the laminate LB is cleaved on the first tape TF, but this is not limiting. The laminate LB may be cleaved when it is transferred from the template substrate 7 to the first tape TF. In this case, the laminate LB may be scribed on the template substrate 7 in advance.

[0073] In Figure 26, the laminate LB is cleaved on the first tape TF, but this is not limiting. The laminate LB transferred to the first tape TF may be transferred to a third tape, and cleavage may be performed on the third tape. For example, a scribe or the like may be performed on the surface of the laminate LB opposite to the surface that contacts the third tape, and a breaking blade or the like may be used to apply stress to the laminate LB from the back side of the third tape (through the third tape), thereby cleaving the laminate LB. The third tape may be a dicing tape.

[0074] In this case, the base material of the first tape TF may be formed from a material with a greater Young's modulus than the third tape. This reduces deformation of the first tape TF when the first tape TF is pressed against the laminate LB, thereby preventing misalignment of the laminate LB. On the other hand, because the third tape is more flexible than the first tape TF, when stress is applied to the laminate LB, for example during a breaking process, the third tape can more easily conform to the shape of the breaking blade, allowing stress to be applied to a more concentrated area, making it easier to cleave the laminate LB.

[0075] In this case, the semiconductor laser element obtained by cleavage on the third tape may be transferred to the (heat-resistant) second tape TS and then transferred to the support substrate SK. Alternatively, the semiconductor laser element obtained by cleavage on the third tape may be transferred to the fourth tape, and then transferred to the (heat-resistant) second tape TS, and then transferred (bonded) to the support substrate SK (junction-down mounting is possible). The base material of the first tape TF may be made of, for example, PET, and the base material of the third tape may be made of, for example, polyolefin. The Young's modulus of the first tape TF may be, for example, 2000 MPa or more, and the Young's modulus of the third tape may be, for example, 1500 MPa or less.

[0076] The laminate LB can be transferred to the third tape so that the upper surface of the laminate LB is exposed. For example, if the first semiconductor layer S1 is grown so that the upper surface (growth surface) of the first semiconductor layer S1 is the c-plane, which is the (0001) plane, the upper surface of the laminate LB is also the c-plane (Ga-plane), and cleavage can be easily performed by scribing the Ga-plane for cleavage.

[0077] Furthermore, the thickness of the laminate LB excluding the electrodes (the thickness of the semiconductor layers in the laminate) may be, for example, 10 μm or more, which prevents the cleaved laminate LB from bending without cracking, thereby improving yield.

[0078] 27, the semiconductor laser element on the first tape TF is transferred to the second tape TS and then bonded to the support substrate SK, but this is not limiting. The semiconductor laser element on the first tape TF may be transferred (bonded) to the support substrate SK and connected to the wiring on the support substrate SK via bonding wires, for example. Also, the semiconductor laser element obtained by cleaving the laminate LB transferred (from the first tape TF) to the third tape may be transferred (bonded) to the support substrate SK (from the third tape) (junction-down mounting is possible).

[0079] FIG. 28 is a flowchart illustrating another example of a method for manufacturing the semiconductor laser device according to the first embodiment. FIG. 29 is a schematic diagram illustrating a method for manufacturing the semiconductor laser device of FIG. 28. The manufacturing method illustrated in FIGS. 28 and 29 includes a step of scribing the laminate LB on the template substrate 7 (for example, forming a crack SC at the m-plane cleavage initiation point) and simultaneously cleaving the laminate LB to form a pair of cavity end faces F1 and F2. In this step, cleavage naturally progresses due to the release of internal stress in the laminate LB caused by scribing. The cavity length (cavity length) can be 200 μm or less, but is not limited thereto and may be 200 μm or more. Thereafter, a step of separating the base semiconductor portion 8 from the template substrate 7 by bonding the semiconductor laser body 21 to a support substrate SK is performed.

[0080] Example 2 FIG. 30 is a perspective view showing the configuration of a semiconductor laser body according to Example 2. FIG. 31 is a cross-sectional view showing the configuration of a semiconductor laser body according to Example 2. In Example 1, the second electrode E2 is provided on the same side as the first electrode E1 with respect to the base semiconductor portion 8, but this is not limiting. As shown in FIGS. 30 and 31, the second electrode E2 may be provided on a different side of the base semiconductor portion 8 from the first electrode E1 (i.e., the back surface of the base semiconductor portion 8). The configurations of the base semiconductor portion 8, the compound semiconductor portion 9, and the first electrode E1 are the same as those of Example 1. This shortens the current path between the first and second electrodes E1 and E2, thereby improving the light emission efficiency of the active layer 9K.

[0081] 32 is a cross-sectional view showing the configuration of a semiconductor laser device according to Example 2. The semiconductor laser device 23 includes a semiconductor laser body 21 including a base semiconductor portion 8 and a compound semiconductor portion 9, a support ST that holds the semiconductor laser body 21, and a conductive film MF that contacts a second electrode E2. The second electrode E2 is located on the back surface of the base semiconductor portion 8, and the compound semiconductor portion 9 and the first electrode E1 are closer to the support ST than the base semiconductor portion 8 (junction-down type).

[0082] The support ST (e.g., a submount) includes first and second conductive pads P1 and P2 and first and second conductive joints A1 and A2. The first electrode E1 is connected to the first pad P1 via the first joint A1, and the second electrode E2 is connected to the second pad P2 via the conductive film MF and the second joint A2.

[0083] Fig. 33 is a flowchart showing another example of the method for manufacturing the semiconductor laser device according to Example 2. Fig. 34 is a schematic diagram showing the method for manufacturing the semiconductor laser device of Fig. 33. The manufacturing method shown in Figs. 33 and 34 includes the steps of preparing a template substrate 7 including an underlying substrate UK and a mask layer 6, forming a first semiconductor layer S1 (and a third semiconductor layer S3) that will be the basis of the base semiconductor portion 8 by the ELO method, forming a second semiconductor layer S2 (and a fourth semiconductor layer S4) that will be the basis of the compound semiconductor portion 9, forming a stacked body LB that has the first semiconductor layer S1, the second semiconductor layer S2 including a ridge portion, and the first electrode E1, the second electrode E2, etc., and bonding the stacked body LB to a support substrate SK to form the first semiconductor layer S2 (and a fourth semiconductor layer S4). The method includes the steps of: separating the layer S1 from the template substrate 7; forming a second electrode E2 on the back surface of the laminate LB (the lower surface of the first semiconductor layer S1); forming a conductive film MF in contact with the second electrode E2 and (the second pad portion P2 of) the support substrate SK; cleaving the laminate LB on the support substrate SK (m-plane cleavage of the nitride semiconductor layer) to form a pair of resonant cavity facets F1 and F2 (an optical resonator LK including the pair of resonant cavity facets F1 and F2); forming a reflector film UF on each of the pair of resonant cavity facets F1 and F2; and dividing the support substrate SK into a plurality of supports ST.

[0084] Fig. 35 is a perspective view showing the configuration of a semiconductor laser device according to Example 2. As shown in Fig. 35, the semiconductor laser device 23 includes a semiconductor laser body 21 and a support ST. The support ST has two wide portions SH having a width greater than the resonance length of the semiconductor laser body 21, and a mounting portion SB located between the two wide portions SH and having a width smaller than the resonance length.

[0085] The support ST includes a T-shaped first pad portion P1 and a second pad portion P2. The first pad portion P1 includes a mounting portion J1 located on the wide portion SH and having a length in the Y direction greater than the resonance length L1, and a contact portion Q1 located on the mounting portion SB and having a length in the Y direction smaller than the resonance length L1. The second pad portion P2 includes a mounting portion J2 located on the wide portion SH and having a length in the Y direction greater than the resonance length L1, and a contact portion Q2 located on the mounting portion SB and having a length in the Y direction smaller than the resonance length L1. The contact portions Q1 and Q2 are aligned in the X direction on the upper surface of the mounting portion SB, and a second joint portion A2 is formed on the contact portion Q2. The first joint portion A1 contacts the first electrode E1 (anode) of the semiconductor laser body 21. The contact portion Q2 of the second pad portion P2 contacts the conductive film MF of the semiconductor laser body 21, thereby electrically connecting the second electrode E2 (cathode) and the second pad portion P2.

[0086] Example 3 In Examples 1 and 2, the first semiconductor layer S1 (ELO semiconductor layer) that forms the base semiconductor portion 8 can be a GaN layer. Alternatively, an InGaN layer, which is a GaN-based semiconductor layer, can be formed as the ELO semiconductor layer. The lateral deposition of the InGaN layer is performed at a low temperature, for example, below 1000°C. This is because at high temperatures, the vapor pressure of indium increases and it is not effectively incorporated into the film. Lowering the deposition temperature has the effect of reducing the mutual reaction between the mask portion 5 and the InGaN layer. Furthermore, the InGaN layer has the effect of being less reactive with the mask portion 5 than the GaN layer. It is desirable to incorporate indium into the InGaN layer at an In composition level of 1% or more, as this further reduces the reactivity with the mask portion 5. Triethylgallium (TEG) is preferably used as the gallium source gas.

[0087] Example 4 FIG. 36 is a perspective view showing the configuration of a semiconductor laser module of Example 4. The semiconductor laser module 24 (semiconductor laser device) of FIG. 36 is a surface-mount package and includes a housing 35 and a semiconductor laser element 23 (see, for example, FIG. 15). The semiconductor laser element 23 includes a plurality of semiconductor laser bodies 21, and the side surface (surface parallel to the cavity end face) of the support body ST is provided so as to face the bottom surface 37 of the housing 35. Therefore, the emission surface (emission-side cavity end face F1) of each semiconductor laser body 21 faces the top surface 34 (transparent plate) of the housing 35, and laser light is emitted from the top surface 34 of the housing 35. The semiconductor laser element 23 is connected to an external connection pin 33 via a wire 31.

[0088] Fig. 37 is a perspective view showing another configuration of the semiconductor laser module of Example 4. The semiconductor laser module 24 (semiconductor laser device) of Fig. 37 is a TO-can mounting type package, and includes a stem 38 and a semiconductor laser element 23 (see Fig. 13, for example). The semiconductor laser element 23 is disposed on a heat block 36 protruding from the base of the stem 38. First and second pad portions P1 and P2 of the semiconductor laser element 23 are connected to external connection pins 33 via wires 31.

[0089] In conventional technology, it was necessary to individually die-bond semiconductor laser chips to a submount to form a CoS (Chip on Submount). However, in Examples 1 to 4, the support ST of the semiconductor laser element 23 functions as a submount, and the semiconductor laser element 23 itself has a CoS structure, eliminating the need for die-bonding to a submount. This eliminates the difficulty of handling when the resonance length (cavity length) is short or the chip width (size in the X direction) is narrow. Specifically, the semiconductor laser element 23 has first and second pad portions P1 and P2 that meet the size requirements for wire bonding on the support ST. These first and second pad portions P1 and P2 are electrically connected to the first and second electrodes (anode and cathode) of the semiconductor laser body 21 (semiconductor laser chip). Therefore, it is sufficient to electrically connect the external connection pins 33 of the package to the first and second pad portions P1 and P2 with wires 31.

[0090] Example 5 Fig. 38 is a schematic diagram showing the configuration of an electronic device according to Example 5. The electronic device 50 in Fig. 38 includes a semiconductor laser device ZD (21 to 24) according to Examples 1 to 4, and a control unit 80 including a processor and controlling the semiconductor laser device ZD. Examples of the electronic device 50 include a lighting device, a display device, a communication device, an information processing device, a medical device, an electric vehicle (EV), etc.

[0091] Example 6 In the first embodiment, the compound semiconductor portion 9 is provided on the c-plane of the base semiconductor portion 8, and the pair of cavity facets are the m-planes of the nitride semiconductor, but this is not limiting. As shown in FIG. 39, the compound semiconductor portion 9 can be provided on the m-plane ((1-100) plane) of the base semiconductor portion 8, and the pair of cavity facets can be the c-plane ((0001) plane) of the nitride semiconductor. The cavity length L1 is the length in the c-axis direction. The cavity facets F1 can be formed, for example, by c-plane cleavage of the nitride semiconductor.

[0092] The above-described technical aspects are intended to be illustrative and explanatory, and not limiting. Many variations will be apparent to those skilled in the art based on these examples and descriptions.

[0093] [Additional Notes] The invention according to the present disclosure has been described above based on the drawings and examples. However, the invention according to the present disclosure is not limited to the above-described embodiments. In other words, the invention according to the present disclosure can be modified in various ways within the scope of the present disclosure, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the invention according to the present disclosure. In other words, it should be noted that a person skilled in the art can easily make various modifications or corrections based on the present disclosure. It should also be noted that these modifications or corrections are included in the scope of the present disclosure. [Explanation of symbols]

[0094] 7 Template substrate 8 Base Semiconductor Section 9 Compound Semiconductor Department 21 Semiconductor laser body 22 Semiconductor laser substrate 23 Semiconductor laser element 24 Semiconductor laser module S1 First semiconductor layer S2 Second semiconductor layer LK optical resonator RJ Ridge Club B1 Part 1 B2 Part 2 (low dislocation area) B3 Part 3 (low dislocation area) F1·F2 A pair of resonant end faces P1 First pad section P2 Second pad section E1 1st electrode E2 2nd electrode UF reflective mirror film ST support SB placement area SK support board

Claims

1. a base semiconductor portion; a compound semiconductor portion located on the base semiconductor portion and including a GaN-based semiconductor; the base semiconductor portion includes a first portion and a second portion having a lower density of threading dislocations extending in a thickness direction than the first portion; the compound semiconductor portion has an optical resonator including a pair of resonant end faces; at least one of the pair of resonator end faces is an m-plane or a c-plane of the compound semiconductor portion, The semiconductor laser body has a resonant length, which is the distance between the pair of resonant end faces, of 200 μm or less.

2. a base semiconductor portion; a compound semiconductor portion located on the base semiconductor portion, the base semiconductor portion includes a first portion and a second portion having a lower density of threading dislocations extending in a thickness direction than the first portion; the compound semiconductor portion has an optical resonator including a pair of resonant end faces; at least one of the pair of resonator end faces is included in a cleavage plane of the compound semiconductor portion, The semiconductor laser body has a resonant length, which is the distance between the pair of resonant end faces, of 200 μm or less.

3. a base semiconductor portion; a compound semiconductor portion located on the base semiconductor portion, the base semiconductor portion includes a first portion and a second portion having a lower density of threading dislocations extending in a thickness direction than the first portion; the compound semiconductor portion has an optical resonator including a pair of resonant end faces; At least one of the pair of cavity end faces has an optical reflectance of 98% or more, The semiconductor laser body has a resonant length, which is the distance between the pair of resonant end faces, of 200 μm or less.

4. 4. The semiconductor laser element according to claim 1, wherein the sum of the thickness of said base semiconductor portion and the thickness of said compound semiconductor portion is 50 μm or less.

5. 5. The semiconductor laser body according to claim 1, wherein the base semiconductor portion is a free-standing layer having no support member.

6. 6. The semiconductor laser body according to claim 1, further comprising a reflecting mirror film covering at least one of the pair of cavity end faces.

7. one of the pair of cavity end faces includes a light emitting region, 7. The semiconductor laser body according to claim 1, wherein the light emitting region overlaps with the second portion in a plan view seen in the thickness direction.

8. the base semiconductor portion includes a base end face parallel to the pair of resonator end faces, 8. The semiconductor laser body according to claim 1, wherein the dislocation density at the base end face is equal to or greater than the threading dislocation density in the second portion.

9. 8. The semiconductor laser body according to claim 1, wherein a ratio of the resonant cavity length to the thickness of the second portion is 1-20.

10. the size of the second portion in a direction perpendicular to a direction defining the resonance length is defined as a width of the second portion; 10. The semiconductor laser body according to claim 1, wherein a ratio of the resonant cavity length to the width of the second portion is 1-10.

11. a size of the first portion in a direction perpendicular to a direction defining the resonance length is defined as a width of the first portion; 11. The semiconductor laser body according to claim 1, wherein a ratio of the resonant length to the width of the first portion is 1-200.

12. 12. The semiconductor laser body according to claim 1, wherein the threading dislocation density of the second portion is equal to or less than 1 / 5 of the threading dislocation density of the first portion.

13. the base semiconductor portion includes a third portion having a threading dislocation density extending in a thickness direction that is lower than that of the first portion, 13. The semiconductor laser body according to claim 1, wherein the first portion is located between the second portion and the third portion.

14. 14. The semiconductor laser device according to claim 1, wherein the compound semiconductor portion includes an n-type semiconductor layer, an active layer, and a p-type semiconductor layer.

15. 15. The semiconductor laser body according to claim 14, wherein the optical resonator includes at least a portion of the n-type semiconductor layer, at least a portion of the active layer, and at least a portion of the p-type semiconductor layer.

16. the compound semiconductor portion includes a ridge portion, The semiconductor laser body according to claim 15 , wherein the ridge portion overlaps with the second portion in a plan view seen in the thickness direction.

17. The semiconductor laser body according to claim 16 , wherein the ridge portion does not overlap the first portion in a plan view.

18. the n-type semiconductor layer includes a first cladding layer, the p-type semiconductor layer includes a second cladding layer, 18. The semiconductor laser body according to claim 16, wherein at least a portion of the second cladding layer is included in the ridge portion.

19. the n-type semiconductor layer includes a first optical guiding layer that is closer to the active layer than the first cladding layer; 20. The semiconductor laser body according to claim 18, wherein the p-type semiconductor layer includes a second optical guide layer that is closer to the active layer than the second cladding layer.

20. an insulating film covering a side surface of the ridge portion, 19. The semiconductor laser body according to claim 18, wherein the refractive index of the insulating film is smaller than the refractive index of the second cladding layer.

21. 21. The semiconductor laser body according to claim 1, wherein a scribe mark exists on at least one of the pair of cavity end faces.

22. 22. The semiconductor laser body according to claim 1, further comprising a first electrode that overlaps with the optical resonator in a plan view seen in the thickness direction.

23. The semiconductor laser body according to claim 22 , wherein the first electrode overlaps with the second portion in a plan view.

24. 24. The semiconductor laser body according to claim 22, wherein the first electrode has a shape whose longitudinal direction is a direction that defines the resonant length, and the size in the longitudinal direction is smaller than the resonant length.

25. 25. The semiconductor laser element according to claim 22, further comprising a second electrode located on the same side as the first electrode or on a different side of the base semiconductor portion.

26. the base semiconductor portion includes a third portion having a threading dislocation density extending in a thickness direction that is lower than that of the first portion, 26. The semiconductor laser body according to claim 25, wherein the second electrode overlaps with the third portion in a plan view.

27. 27. The semiconductor laser body according to claim 25, wherein the first electrode is an anode and the second electrode is a cathode.

28. the compound semiconductor portion includes a GaN-based semiconductor, 4. The semiconductor laser body according to claim 2, wherein each of the pair of cavity end faces is an m-plane of the compound semiconductor portion.

29. 30. The semiconductor laser body according to claim 1, wherein the surface roughness of at least one of the pair of resonator end faces is smaller than the surface roughness of a side surface of the compound semiconductor portion parallel to the a-plane.

30. 28. The semiconductor laser body according to claim 27, wherein a power of 200 mW or less is supplied between the first and second electrodes.

31. The threading dislocation density of the second portion is 5×10 ６ / cm ２ 31. The semiconductor laser body according to claim 1, wherein:

32. 32. The semiconductor laser body according to claim 1, wherein the base semiconductor portion includes a GaN-based semiconductor.

33. 33. A semiconductor laser device comprising: the semiconductor laser body according to claim 1; and a support for holding the semiconductor laser body.

34. the support has a mounting portion having a width smaller than the resonance length, 34. The semiconductor laser device according to claim 33, wherein the semiconductor laser body is positioned on the mounting portion so that a width direction of the mounting portion coincides with a direction defining the resonant length.

35. 35. The semiconductor laser device according to claim 34, wherein at least one of the pair of cavity end faces protrudes from the mounting portion in a plan view seen in the thickness direction.

36. the mounting portion is formed between two notched portions facing each other in a direction that defines the resonance length, 36. The semiconductor laser device according to claim 35, wherein the pair of cavity end faces are located on the two notches.

37. 37. The semiconductor laser device according to claim 34, wherein the support includes a first pad portion and a second pad portion whose size in a direction defining the resonance length is larger than the resonance length.

38. 38. The semiconductor laser device according to claim 37, wherein the mounting portion includes a first bonding portion electrically connected to the first pad portion and a second bonding portion electrically connected to the second pad portion.

39. 39. The semiconductor laser device according to claim 38, wherein the second bonding portion has a thickness greater than that of the first bonding portion.

40. 40. The semiconductor laser device according to claim 34, further comprising: a reflector film covering at least one of the pair of cavity end faces; and a dielectric film formed on a side surface of the mounting portion and made of the same material as the reflector film.

41. a plurality of semiconductor laser bodies and a support substrate that holds the plurality of semiconductor laser bodies; A semiconductor laser substrate, wherein each semiconductor laser body is the semiconductor laser body according to any one of claims 1 to 32.

42. An electronic device comprising the semiconductor laser device according to any one of claims 1 to 32.

43. forming a strip-shaped first semiconductor layer on a template substrate by an ELO method; forming a second semiconductor layer on the first semiconductor layer; forming a pair of cavity end faces on the second semiconductor layer so that a cavity length, which is the distance between the pair of cavity end faces, is 200 μm or less.

44. 44. The method for manufacturing a semiconductor laser device according to claim 43, wherein at least one of the pair of resonant cavity facets is formed by cleaving the second semiconductor layer.

45. the second semiconductor layer includes a GaN-based semiconductor; 45. The method for manufacturing a semiconductor laser device according to claim 43, wherein the pair of cavity end faces are m-planes of the second semiconductor layer.

46. forming a third semiconductor layer on the template substrate, the third semiconductor layer being the same layer as the first semiconductor layer; forming a fourth semiconductor layer on the third semiconductor layer, the fourth semiconductor layer being the same layer as the second semiconductor layer; The method for manufacturing a semiconductor laser device according to any one of claims 43 to 45, wherein a pair of cavity end faces is formed in the fourth semiconductor layer.

47. the first semiconductor layer includes a first portion and a second portion having a threading dislocation density that is 1 / 5 or less of that of the first portion; 47. A method for manufacturing a semiconductor laser device according to claim 43, further comprising forming a ridge portion in the second semiconductor layer that overlaps with the second portion in a planar view before forming the pair of resonant cavity end faces.

48. forming a first electrode; 48. A method for manufacturing a semiconductor laser device according to claim 43, further comprising the step of bonding a stack including the first semiconductor layer, the second semiconductor layer, and the first electrode to a support substrate.

49. 49. The method of claim 48, further comprising the step of separating the stack from the template substrate.

50. 50. The method for manufacturing a semiconductor laser device according to claim 49, wherein the pair of resonant cavity facets are formed in a second semiconductor layer included in the stack on the support substrate.

51. 50. The method for manufacturing a semiconductor laser device according to claim 49, wherein the pair of resonant cavity end faces are formed when the laminate is bonded to the support substrate.

52. forming a first electrode; transferring a stacked body including the first semiconductor layer, the second semiconductor layer, and the first electrode from the template substrate to a first tape; The method for manufacturing a semiconductor laser device according to any one of claims 43 to 47, wherein at least one of the pair of resonator end faces is formed on the first tape.

53. 53. The method for manufacturing a semiconductor laser device according to claim 52, wherein at least one of the pair of resonator end faces is formed by scribing the laminate on the first tape.

54. forming a first electrode; transferring a stacked body including the first semiconductor layer, the second semiconductor layer, and the first electrode from the template substrate to a first tape; 48. The method for manufacturing a semiconductor laser device according to claim 43, wherein at least one of the pair of resonator end faces is formed when the laminate is transferred to the first tape.

55. 55. A method for manufacturing a semiconductor laser device according to any one of claims 52 to 54, wherein a semiconductor laser element located on the first tape and including the pair of resonant cavity end faces is transferred to a second tape, and then the semiconductor laser element located on the second tape is bonded to a support substrate.

56. 56. The method for manufacturing a semiconductor laser device according to claim 50, further comprising the step of forming a reflecting mirror film on each of the pair of cavity end faces on the support substrate.

57. 56. The method for manufacturing a semiconductor laser device according to claim 50, wherein the support substrate is divided into a plurality of support members, and each support member holds one or more semiconductor laser bodies including the pair of resonant cavity facets.

58. 58. The method for manufacturing a semiconductor laser device of claim 57, wherein the one or more semiconductor laser bodies are held on the support in a junction-down manner.

59. An apparatus for manufacturing a semiconductor laser device, which performs each step according to claim 43.

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