Surface-emitting laser and surface-emitting laser array

Abstract

Provided is a surface-emitting laser which makes it possible to inhibit a forming process for a polarization control structure from becoming complicated.　A surface-emitting laser according to the present technology is provided with a light-emitting element part including a first structure and a second structure that is provided on the first structure and has a mesa portion. The first structure and / or the second structure has an active layer having a light-emitting region. The first structure has an oxide structure that imparts anisotropic stress to the active layer.

Description

Surface-emitting lasers and surface-emitting laser arrays

[0001] The technology disclosed herein (hereinafter also referred to as "this technology") relates to surface-emitting lasers and surface-emitting laser arrays.

[0002] Conventionally, vertical cavity surface-emitting lasers (VCSELs) are known.

[0003] Some conventional surface-emitting lasers have a grating in the mesa portion that acts as a polarization control structure (see, for example, Patent Document 1).

[0004] Japanese Patent Application Publication No. 5-21889

[0005] However, conventional surface-emitting lasers have led to a complicated process for forming polarization-controlled structures.

[0006] Therefore, the main objective of this technology is to provide a surface-emitting laser that can suppress the complexity of the process for forming polarization-controlled structures.

[0007] This technology provides a surface-emitting laser comprising a light-emitting portion including a first structure and a second structure having a mesa portion provided on the first structure, wherein the first structure or the second structure has an active layer having a light-emitting region, and the first structure has an oxidation structure that imparts anisotropic stress to the active layer. The oxidation structure may be provided on the outer periphery or inside the first structure. The first structure may have a longitudinal shape in plan view. The oxidation structure may have first and second oxidation portions that sandwich the light-emitting region in plan view. Each of the first and second oxidation portions may overlap the mesa portion in plan view at least in part. The oxidation structure may be circumferential in plan view. The second structure may have the active layer, and the mesa portion may have at least the light-emitting region of the active layer. The mesa portion may have an oxidation constriction layer that sets the light-emitting region. The mesa portion has an oxidation constriction layer that sets the light-emitting region, and the oxidation constriction layer has a non-oxidized region and an oxidized region surrounding the non-oxidized region, and each of the first and second oxidized portions may overlap with the oxidized region in plan view, at least a portion of which may overlap. The second structure may have sidewall portions on one side and / or the other side of the mesa portion in the longitudinal direction of the first structure. The second structure may have a first sidewall portion as the sidewall portion provided on the one side and a second sidewall portion as the sidewall portion provided on the other side. The second structure may have a connecting portion that connects the mesa portion and the sidewall portion. The second structure may include a first side wall portion provided on one side as the side wall portion, a second side wall portion provided on the other side as the side wall portion, a first connecting portion connecting the mesa portion and the first side wall portion, and a second connecting portion connecting the mesa portion and the second side wall portion. At least the mesa portion of the mesa portion and the side wall portion may be covered with at least an electrode from the side opposite to the first structure. The side wall portion may be covered with at least the electrode from the side opposite to the first structure. A part of the electrode may be provided directly or via an insulating film in the groove formed by the first structure, the mesa portion and the side wall portion.The electrode may be a bonding electrode that is bonded to a mounting substrate via bumps. The technology also provides a surface-emitting laser array comprising a plurality of surface-emitting lasers, each including a light-emitting portion comprising a first structure and a second structure having a mesa portion provided on the first structure, wherein the first structure and / or the second structure have an active layer having an emitting region, and the first structure has an oxidation structure that imparts anisotropic stress to the active layer. The first structure of the plurality of surface-emitting lasers may have a longitudinal direction in plan view. The plurality of surface-emitting lasers may be arranged such that the longitudinal directions of two adjacent surface-emitting lasers are parallel or perpendicular.

[0008] This is a cross-sectional view (part 1) of a surface-emitting laser according to Example 1 of one embodiment of this technology. This is a cross-sectional view (part 2) of a surface-emitting laser according to Example 1 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser according to Example 1 of one embodiment of this technology. This is a cross-sectional view of the oxidation constriction layer and oxide layer of a surface-emitting laser according to Example 1 of one embodiment of this technology. This is a cross-sectional view of the oxide structure of a surface-emitting laser according to Example 1 of one embodiment of this technology. This is a flowchart for explaining an example of a method for manufacturing a surface-emitting laser according to Example 1 of one embodiment of this technology. Figures 7A and 7B are cross-sectional views of each step of an example of a method for manufacturing a surface-emitting laser according to Example 1 of one embodiment of this technology. Figures 8A and 8B are cross-sectional views of each step of an example of a method for manufacturing a surface-emitting laser according to Example 1 of one embodiment of this technology. Figures 9A and 9B are cross-sectional views of each step of an example of a method for manufacturing a surface-emitting laser according to Example 1 of one embodiment of this technology. Figures 10A and 10B are cross-sectional views of each step of an example of a method for manufacturing a surface-emitting laser according to Example 1 of one embodiment of this technology. Figures 11A and 11B are cross-sectional views of each step of an example of a method for manufacturing a surface-emitting laser according to Example 1 of one embodiment of this technology. Figures 12A and 12B are cross-sectional views of each step of an example of a method for manufacturing a surface-emitting laser according to Example 1 of one embodiment of this technology. Figures 13A and 13B are cross-sectional views of each step of an example of a method for manufacturing a surface-emitting laser according to Example 1 of one embodiment of this technology. Figures 14A and 14B are cross-sectional views of each step of an example of a method for manufacturing a surface-emitting laser according to Example 1 of one embodiment of this technology. Figure 15A is a cross-sectional view (1) of a light-emitting device according to Example 2 of one embodiment of this technology. Figure 15B is a cross-sectional view (2) of a light-emitting device according to Example 2 of one embodiment of this technology. This is a cross-sectional view (1) of a light-emitting device according to Example 3 of one embodiment of this technology. This is a cross-sectional view (2) of a light-emitting device according to Example 3 of one embodiment of this technology. This is a schematic plan view of the surface-emitting laser array of the light-emitting device according to Example 3 of one embodiment of this technology. This is a cross-sectional view (1) of a surface-emitting laser according to Example 4 of one embodiment of this technology. This is a cross-sectional view (part 2) of a surface-emitting laser according to Example 4 of one embodiment of this technology. This is a cross-sectional view (part 1) of a surface-emitting laser according to Example 5 of one embodiment of this technology.Figure 25A is a cross-sectional view (part 2) of a surface-emitting laser according to Example 5 of one embodiment of this technology. Figure 27B is a cross-sectional view (part 2) of a surface-emitting laser according to Example 6 of one embodiment of this technology. Figure 27C is a cross-sectional view (part 3) of a surface-emitting laser according to Example 6 of one embodiment of this technology. Figure 28A is a cross-sectional view (part 1) of a surface-emitting laser according to Example 9 of one embodiment of this technology. Figure 28B is a cross-sectional view (part 2) of a surface-emitting laser according to Example 9 of one embodiment of this technology. Figure 28C is a cross-sectional view (part 3) of a surface-emitting laser according to Example 9 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser according to Example 9 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser according to Example 10 of one embodiment of this technology. This is a cross-sectional view (part 1) of a surface-emitting laser according to Example 11 of one embodiment of this technology. This is a cross-sectional view (part 2) of a surface-emitting laser according to Example 11 of one embodiment of this technology. This is a cross-sectional view (part 1) of a surface-emitting laser according to Example 12 of one embodiment of this technology. This is a cross-sectional view (part 2) of a surface-emitting laser according to Example 12 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser according to Example 12 of one embodiment of this technology. This is a cross-sectional view (part 1) of a surface-emitting laser according to Example 13 of one embodiment of this technology. This is a cross-sectional view (part 2) of a surface-emitting laser according to Example 13 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser according to Example 13 of one embodiment of this technology. This is a cross-sectional view (part 1) of a surface-emitting laser according to Example 14 of one embodiment of this technology. This is a cross-sectional view (part 2) of a surface-emitting laser according to Example 14 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser according to Example 14 of one embodiment of this technology.This is a cross-sectional view (1) of a surface-emitting laser according to Example 15 of one embodiment of this technology. This is a cross-sectional view (2) of a surface-emitting laser according to Example 15 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser according to Example 15 of one embodiment of this technology. This is a cross-sectional view (1) of a surface-emitting laser according to Example 16 of one embodiment of this technology. This is a cross-sectional view (2) of a surface-emitting laser according to Example 16 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser according to Example 16 of one embodiment of this technology. This is a cross-sectional view (1) of a surface-emitting laser according to Example 17 of one embodiment of this technology. This is a cross-sectional view (2) of a surface-emitting laser according to Example 17 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser according to Example 17 of one embodiment of this technology. This is a cross-sectional view (1) of a surface-emitting laser according to Example 18 of one embodiment of this technology. This is a cross-sectional view (2) of a surface-emitting laser according to Example 18 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser according to Example 18 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser array according to Example 19 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser array according to Example 20 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser array according to Example 21 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser array of a light-emitting device according to Example 22 of one embodiment of this technology. Figure 58A is a partial plan view of a surface-emitting laser array of a light-emitting device according to Example 22 of one embodiment of this technology. Figure 58B is a partial cross-sectional view of a light-emitting device according to Example 22 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser array of a light-emitting device according to Example 23 of one embodiment of this technology. Figure 60A is a partial plan view of a surface-emitting laser array of a light-emitting device according to Example 23 of one embodiment of this technology. Figure 60B is a partial cross-sectional view of a light-emitting device according to Example 23 of one embodiment of this technology. This is a cross-sectional view of a light-emitting device according to Example 24 of one embodiment of this technology. This is a cross-sectional view (1) of a surface-emitting laser according to a modified example of Example 5 of one embodiment of this technology. This is a cross-sectional view (2) of a surface-emitting laser according to a modified example of Example 5 of one embodiment of this technology. This is a cross-sectional view (1) of a surface-emitting laser according to a modified example of Embodiment 6 of one embodiment of this technology. This is a cross-sectional view (2) of a surface-emitting laser according to a modified example of Embodiment 6 of one embodiment of this technology.This is a cross-sectional view of a surface-emitting laser according to Modification 1 of Example 1 of one embodiment of this technology. This is a cross-sectional view of a surface-emitting laser according to Modification 7 of one embodiment of this technology. This is a cross-sectional view (part 1) of a surface-emitting laser according to Modification 2 of Example 1 of one embodiment of this technology. This is a cross-sectional view (part 2) of a surface-emitting laser according to Modification 2 of Example 1 of one embodiment of this technology. This is a schematic plan view of a surface-emitting laser according to Modification 2 of Example 1 of one embodiment of this technology. This is a cross-sectional view (part 1) of a surface-emitting laser according to Modification 3 of Example 1 of one embodiment of this technology. This is a cross-sectional view (part 2) of a surface-emitting laser according to Modification 3 of Example 1 of one embodiment of this technology. This is a cross-sectional view (part 1) of a surface-emitting laser according to Modification 4 of Example 1 of one embodiment of this technology. This is a cross-sectional view (part 2) of a surface-emitting laser according to Modification 4 of Example 1 of one embodiment of this technology. This is a cross-sectional view (part 1) of a surface-emitting laser according to Modification 11 of one embodiment of this technology. This is a cross-sectional view (part 2) of a surface-emitting laser according to Modification 11 of one embodiment of this technology. This figure shows an example of applying a surface-emitting laser according to Embodiment 1 of this technology to a distance measuring device. This block diagram shows an example of a schematic configuration of a vehicle control system. This is an explanatory diagram showing an example of the installation location of the distance measuring device.

[0009] Preferred embodiments of the present technology will be described in detail below with reference to the attached drawings. In this specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant explanations will be omitted. The embodiments described below represent typical embodiments of the present technology and should not be interpreted as narrowing the scope of the present technology. Even if this specification describes that the surface-emitting laser and surface-emitting laser array relating to the present technology have multiple effects, the surface-emitting laser and surface-emitting laser array relating to the present technology only need to have at least one effect. The effects described in this specification are merely examples and are not limiting, and other effects may also exist.

[0010] Furthermore, the explanation will proceed in the following order: 0. Introduction 1. Surface-emitting laser according to Example 1 of one embodiment of this technology 2. Light-emitting device according to Example 2 of one embodiment of this technology 3. Light-emitting device according to Example 3 of one embodiment of this technology 4. Surface-emitting laser according to Example 4 of one embodiment of this technology 5. Surface-emitting laser according to Example 5 of one embodiment of this technology 6. Surface-emitting laser according to Example 6 of one embodiment of this technology 7. Surface-emitting laser according to Example 7 of one embodiment of this technology 8. Surface-emitting laser according to Example 8 of one embodiment of this technology 9. Surface-emitting laser according to Example 9 of one embodiment of this technology 10. Surface-emitting laser according to Example 10 of one embodiment of this technology 11. Surface-emitting laser according to Example 11 of one embodiment of this technology 12. Surface-emitting laser according to Example 12 of one embodiment of this technology 13. Surface-emitting laser according to Example 13 of one embodiment of this technology 14. Surface-emitting laser according to Example 14 of one embodiment of this technology 15. Surface-emitting laser according to Example 15 of one embodiment of this technology 16. 17. Surface-emitting laser according to Example 16 of one embodiment of this technology 18. Surface-emitting laser according to Example 18 of one embodiment of this technology 19. Surface-emitting laser array according to Example 19 of one embodiment of this technology 20. Surface-emitting laser array according to Example 20 of one embodiment of this technology 21. Surface-emitting laser array according to Example 21 of one embodiment of this technology 22. Light-emitting device according to Example 22 of one embodiment of this technology 23. Light-emitting device according to Example 23 of one embodiment of this technology 24. Light-emitting device according to Example 24 of one embodiment of this technology 25. Modifications of this technology 26. Examples of applications to electronic equipment 27. Example of applying a surface-emitting laser to a distance measuring device 28. Example of mounting a distance measuring device on a mobile body

[0011] <0. Introduction>

[0012] Conventionally, various techniques have been proposed for controlling the polarization of VCSELs. For example, in back-face ejection type VCSELs, a technique is known in which a grating is provided as a polarization control structure in the mesa to control the polarization (see, for example, Patent Document 1).

[0013] However, while it is possible to obtain polarization of any wavelength and direction by changing the width and depth of the grating, as described in Patent Document 1, for example, the process is difficult and requires expensive equipment (for example, an EB (Electron Beam) lithography apparatus) because it is necessary to form a microstructure smaller than the wavelength on the semiconductor layer. In other words, the technology described in Patent Document 1, for example, leads to a complicated process for forming the polarization control structure.

[0014] Therefore, after diligent research, the inventors adopted an oxide structure as the polarization control structure and succeeded in developing a novel technology that suppresses the complexity of the formation process of the polarization control structure by devising its shape and arrangement.

[0015] The inventors then developed a surface-emitting laser according to this technology, which embodies this novel technology. Furthermore, the inventors developed a surface-emitting laser array according to this technology, which comprises multiple such surface-emitting lasers.

[0016] Hereinafter, several embodiments of one example of this technology will be described in detail with reference to the drawings. In the following cross-sectional views such as Figure 1, the upper side will be referred to as "upper" and the lower side as "lower" as appropriate. The terms "identical" and "identical" used in this specification include not only complete identical and complete identical, but also substantially identical and substantially identical (when there are slight differences in the range of equivalent effect). Each cross-sectional view and each plan view is a schematic diagram illustrating a surface-emitting laser, and the shape, size, arrangement, dimensions, etc., do not necessarily correspond to those described in this specification.

[0017] <1. Surface-emitting laser according to Example 1 of one embodiment of the present technology> Figure 1 is a cross-sectional view (part 1) of the surface-emitting laser 10 according to Example 1 of one embodiment of the present technology. Figure 2 is a cross-sectional view (part 2) of the surface-emitting laser 10 according to Example 1 of one embodiment of the present technology. Figure 3 is a schematic plan view of the surface-emitting laser 10 according to Example 1 of one embodiment of the present technology. Figure 1 is a cross-sectional view taken along line 1-1 of Figure 3. Figure 2 is a cross-sectional view taken along line 2-2 of Figure 3.

[0018] <<Configuration of Surface-Emitting Laser>> (Overall Configuration) The surface-emitting laser 10 according to Example 1 of one embodiment of this technology is, as an example, a vertical cavity surface-emitting laser (VCSEL) as shown in Figures 1 to 3. The surface-emitting laser 10 is, as an example, a back-side emission VCSEL.

[0019] The surface-emitting laser 10 is driven by a driver (driving circuit), for example. The driver is configured to include, for example, a power supply and a transistor (e.g., MOSFET: Metal-Oxide-Semiconductor Field-Effect Transistor) that controls the on / off switching of power supplied from the power supply to the surface-emitting laser 10.

[0020] The surface-emitting laser 10 includes, as an example, a light-emitting element R comprising a first structure ST1 and a second structure ST2 having a mesa portion MP, which is provided on the first structure ST1. Hereinafter, the direction in which the first and second structures ST1 and ST2 are stacked (up and down direction) will also be referred to as the "stacking direction".

[0021] The second structure ST2, for example, has an active layer 106 including a light-emitting region LA. The first structure ST1, for example, has an oxidation structure OS that imparts anisotropic stress to the active layer 106.

[0022] Here, the mesa portion MP has at least an luminescent region LA of the active layer 106. The first structure ST1 has a first semiconductor multilayer mirror 103 as at least a part (e.g., all) of the lower mirror and a part (upper part) of the first contact layer 102 in this order from the second structure ST2 side (upper side).

[0023] The surface-emitting laser 10 has the other part (lower part) of the first contact layer 102 and the substrate 101 on the side opposite to the second structure ST2 (upper side) of the first structure ST1, and in this order from the second structure ST2 side (upper side). The back surface (lower surface) of the substrate 101 becomes the emission surface.

[0024] The light-emitting element R, including the first and second structures ST1 and ST2, is projected in a mesa-like manner on the base portion, which includes the substrate 101 and the other (lower) part of the first contact layer 102. In other words, the light-emitting element R has a mesa structure.

[0025] The second structure ST2 has first and second cladding layers 104 and 107 sandwiching the active layer 106 in the stacking direction. The first and second cladding layers 104 and 107 have different conductivity types. That is, the surface-emitting laser 10 includes a resonator having a double heterostructure in which the active layer 106 is sandwiched in the stacking direction by first and second cladding layers 104 and 107 with different conductivity types, and the active layer 106 can perform luminescent recombination (radiative recombination) of holes and electrons.

[0026] An oxidative constriction layer 105 is provided within the mesa section MP (more specifically, within the first cladding layer 104 of the mesa section MP). The oxidative constriction layer 105 sets the light-emitting region LA of the active layer 106. The light-emitting region LA is a region in the active layer 106 where current is injected (current injection region) and which emits light.

[0027] The second structure ST2 has a second semiconductor multilayer reflector 108 as at least a part (for example, all) of the upper reflector and a second contact layer 109 on the side opposite to the first structure ST1 (upper side) of the second cladding layer 107, and in this order from the side of the first structure ST1 (lower side).

[0028] In other words, in the surface-emitting laser 10, the resonator in the light-emitting element R is sandwiched between a lower reflector and an upper reflector.

[0029] The lower and upper mirrors have high reflectivity, enabling vertical optical confinement within the resonator. Furthermore, the oxidized constriction layer 105 has a transverse refractive index distribution within the resonator, enabling transverse optical confinement in the central region with a high refractive index (non-oxidized region). In other words, the surface-emitting laser 10 can achieve high three-dimensional optical confinement near the active layer 106 through both vertical and transverse optical confinement within the resonator.

[0030] The resonator length of the resonator, that is, the optical distance between the lower mirror and the upper mirror, is set to an integer multiple (nλ / 2) of half of the oscillation wavelength λ (λ / 2).

[0031] As can be understood from the above description, in the surface-emitting laser 10, as an example, a first contact layer 102, a first semiconductor multilayer film mirror 103, a first clad layer 104 provided with a constriction oxide layer 105 therein, an active layer 106, a second clad layer 107, a second semiconductor multilayer film mirror 108, and a second contact layer 109 are laminated in this order from the substrate 101 side (lower side).

[0032] The first structure ST1 has a shape in plan view having a longitudinal direction (the direction of line 1-1 in FIG. 3). More specifically, the first structure ST1 has an anisotropic shape such as, for example, a racetrack shape, an elliptical shape, or a rectangular shape in plan view. Here, in plan view, the outer edges of the first and second structures ST1 and ST2 coincide. That is, here, the first and second structures ST1 and ST2 have the same length in the longitudinal direction and the same length in the short transverse direction.

[0033] It is preferable that the second structure ST2 has side wall portions on one side and / or the other side in the longitudinal direction of the first structure ST1 of the mesa portion MP on the first structure ST1. Here, the second structure ST2 has a first side wall portion SWP1 as a side wall portion provided on one side in the longitudinal direction of the first structure ST1 and a second side wall portion SWP2 as a side wall portion provided on the other side in the longitudinal direction of the first structure ST1. That is, in the second structure ST2, the mesa portion MP is sandwiched in the longitudinal direction of the first structure ST1 by the first and second side wall portions SWP1 and SWP2.

[0034] Here, in plan view, the portions of the outer edges of the first side wall portion SWP1 excluding the portion facing the mesa portion MP and the portions of the outer edges of the second side wall portion SWP2 excluding the portion facing the mesa portion MP coincide with the outer edge of the first structure ST1.

[0035] The mesa portion MP is, for example, protruding on the first structure ST1 (here, the first semiconductor multilayer mirror 103). That is, the light-emitting element portion R has a stepped mesa structure. The mesa portion MP is, for example, provided on the central portion of the first structure ST1. The mesa portion MP is, for example, composed of a first cladding layer 104, an oxidation constriction layer 105, an active layer 106, a second cladding layer 107, a second semiconductor multilayer mirror 108, and a second contact layer 109. Here, as described above, the mesa portion MP has at least the light-emitting region LA in the active layer 106. When the mesa portion MP has the light-emitting region LA, it is also called a "light-emitting mesa", a "light-emitting portion", or an "emitter portion". The mesa portion MP is also called a "columnar portion" regardless of the presence or absence of the light-emitting region LA.

[0036] The shape of the mesa portion MP is preferably an isotropic shape. Here, the shape of the mesa portion MP is a cylinder (see FIGS. 1 to 3), but it is not limited thereto, and other shapes such as an elliptical cylinder (preferably having an aspect ratio close to 1), a polygonal prism (preferably a regular polygonal prism), a truncated cone, a truncated elliptical cone (preferably having an aspect ratio close to 1), and a truncated polygonal pyramid (preferably a regular truncated polygonal pyramid) may be used. Here, the mesa diameter, which is the diameter of the mesa portion MP, coincides with the minor axis length (length in the short side direction) of the first structure ST1. The diameter of the mesa portion MP is, for example, several μm to several tens of μm. The height of the mesa portion MP is, for example, several μm to several tens of μm.

[0037] The first and second side wall portions SWP1 and SWP2 have substantially the same layer structure as the mesa portion MP. That is, each side wall portion is, for example, composed of a first cladding layer 104, an oxide layer 119, an active layer 106, a second cladding layer 107, a second semiconductor multilayer mirror 108, and a second contact layer 109. The upper surfaces of the first and second side wall portions SWP1 and SWP2 are on the same plane as the upper surface of the mesa portion MP. The planar shape of each side wall portion is, for example, substantially arc-shaped (see FIG. 3).

[0038] Here, a first groove T1 is formed by the first structure ST1, the mesa portion MP, and the first sidewall portion SWP1, and a second groove T2 is formed by the second structure ST2, the mesa portion MP, and the second sidewall portion SWP2. The bottom surfaces of the first and second grooves T1 and T2 coincide with the boundary between the upper surface of the first structure ST (here, the upper surface of the first semiconductor multilayer reflector 103) and the lower surface of the second structure ST (here, the lower surface of the first cladding layer 104). That is, the bottom surfaces of the first and second grooves T1 and T2 are located at least on the substrate 101 side (lower side) of the oxidation constriction layer 105. Note that an etching stop layer (e.g., an InGaAs layer, an InGaAsP layer) may be provided between the first semiconductor multilayer reflector 103 and the first cladding layer 104.

[0039] The entire surface of the light-emitting element R (except for the electrode contact area of ​​the second contact layer 109 at the top of the mesa portion MP) is covered with an insulating film 111. More specifically, the insulating film 111 is provided along the sides and top surfaces of the first and second sidewall portions SWP1 and SWP2, and along the first and second grooves T1 and T2. Note that the insulating film 111 is not shown in Figure 3 (the same applies to other schematic plan views).

[0040] The anode electrode, which serves as the first electrode 112, is provided on the first contact layer 102 so as to surround the light-emitting element R via the insulating film 111.

[0041] The mesa portion MP is covered by a cathode electrode, which serves as the second electrode 113, from the side opposite to the first structure ST1 (top) and from the side. Here, the central portion 113a of the second electrode 113 is provided on the second contact layer 109. The first sidewall portion SWP1 is covered by one end portion 113b of the second electrode 113 via an insulating film 111 from the side opposite to the first structure ST1 (top). The second sidewall portion SWP2 is covered by the other end portion 113c of the second electrode 113 via an insulating film 111 from the side opposite to the first structure ST1 (top). A connecting portion 113d is provided in and on the first groove T1, connecting the central portion 113a and one end portion 113b of the second electrode 113 via an insulating film 111. A connecting portion 113e is provided within and on the second groove T2, connecting the central portion 113a and the other end portion 113c of the second electrode 113 via an insulating film 111.

[0042] In this way, by providing the second electrode 113 over substantially the entire area of ​​the second structure ST, which includes the mesa portion MP and the first and second sidewall portions SWP1 and SWP2, the entire light-emitting element R can receive the load when, for example, the surface-emitting laser 10 is joined to the drive substrate as a mounting substrate via conductive bumps (when flip-chip mounting). Therefore, even when the surface-emitting laser 10 has a small diameter mesa portion MP, damage to the mesa portion MP can be suppressed. Furthermore, since the thermal and electrical contact area between the light-emitting element R and the drive substrate is increased, improvements in electrical characteristics, including heat dissipation and responsiveness, can be expected. For the second electrode 113, for example, a metal film stacked in the order of Ti / Pt / Au from the second contact layer 109 side can be used.

[0043] In other words, the surface-emitting laser 10 has an intracavity structure in which, for example, the first electrode 112 and the second electrode 113 are arranged on the surface side (top side) of the substrate 101. This makes it possible to reduce the element resistance (element voltage).

[0044] The second electrode 113 can be used as a bonding electrode that is joined to a mounting substrate (e.g., a drive board with a driver, a wiring board connected to a driver, a submount, etc.) via bumps.

[0045] The surface-emitting laser 10 can, for example, be mounted on a substrate using a junction-down (flip-chip) configuration.

[0046] (Substrate) The substrate 101 is, for example, a semi-insulating substrate or an insulating substrate, such as an SI (Semi-Insulated)-GaAs substrate or an i-GaAs substrate. The thickness of the substrate 101 is, for example, 100 μm. Semi-insulating substrates and insulating substrates that have little or no impurity doping have low light absorption and are particularly suitable for back-side emission VCSELs, such as in this embodiment, where laser light is emitted from the back surface of the substrate 101. As the GaAs substrate 101, various surface orientation substrates such as (n11)-plane substrates can be used, but a (100)-plane substrate is preferred for reasons such as substrate cost and the aperture shape of the oxide constriction layer 105, which will be described later. Furthermore, an anti-reflective coating (ARC) and an on-chip lens (OCL) for controlling the emission direction and radiation angle may be formed on the back surface of the substrate 101, i.e., the emission surface.

[0047] (First Contact Layer) The first contact layer 102 is made of a p-type compound semiconductor, for example, a p-GaAs layer. The first contact layer 102 is a semiconductor layer for making the anode electrode, which is the first electrode 112, into ohmic contact with the first semiconductor multilayer reflector 103, and is a semiconductor layer doped with a high concentration of p-type impurities (for example, C). The thickness of the first contact layer 102 is, for example, 2 μm.

[0048] (First Semiconductor Multilayer Reflector) The first semiconductor multilayer reflector 103 is, as an example, a p-type semiconductor multilayer reflector doped with p-type impurities, which has low light absorption, high reflectivity and conductivity. A multilayer reflector is also called a distributed Bragg reflector (DBR). The first semiconductor multilayer reflector 103 has a structure in which non-oxidized regions 103b1 of high refractive index layers 103a and low refractive index layers 103b, which have different refractive indices, are alternately stacked with an optical thickness of 1 / 4 wavelength of the emission wavelength of the active layer 106. The non-oxidized region 103b1 of the low refractive index layer 103b is made of an Al-containing compound semiconductor (e.g., AlGaAs, AlAs, etc.). The high refractive index layer 103a is made of a compound semiconductor (e.g., AlGaAs, GaAs, etc.). The non-oxidizing region 103b1 of the low refractive index layer 103b is a high-Al composition layer with a higher Al composition than the high refractive index layer 103a. It is preferable that the refractive index difference (Al composition difference) between the high refractive index layer 103a and the non-oxidizing region 103b1 of the low refractive index layer 103b be as large as possible. This is because a high reflectivity can be obtained with a small number of pairs.

[0049] The refractive indices of the non-oxidizing region 103b1 of the low refractive index layer 103b and the high refractive index layer 103a are, for example, Al ｘ Ga １－ｘ The Al composition x can be adjusted with As (0 ≤ x ≤ 1), and the higher the Al composition x (lower the Ga composition), the lower the refractive index layer obtained. In this embodiment, as the first semiconductor multilayer reflector 103, for example, a p-DBR can be used in which multiple periods of alternating p-AlGaAs high refractive index layers (C-doped, 45-60 nm thick) with an Al composition x of 0.4 or less and p-AlGaAs low refractive index layers (C-doped, 50-65 nm thick) with an Al composition x of 0.8 or more are stacked. The number of repeated stacks of the p-DBR is set so that the reflectance for the desired oscillation wavelength (940 nm) is lower than that of the second semiconductor multilayer reflector 108 (n-DBR) described later (for example, 97.79%) (the required number of stacks can be derived based on the composition and thickness of each layer).

[0050] (First cladding layer) The first cladding layer 104 consists, for example, of a p-type compound semiconductor, such as a p-AlGaAs layer (C-doped, approximately 315 nm thick). The "cladding layer" is also called a "spacer layer". The Al composition of the first cladding layer 104 is, for example, 0.3 to 0.5 (for example, 0.4).

[0051] (Oxidation Constriction Layer) Figure 4 is a cross-sectional view of the oxidation constriction layer 105 and the oxide layer 119 of a surface-emitting laser 10 according to Example 1 of one embodiment of the present technology. The oxidation constriction layer 105 has, for example, a non-oxidized region 105a included in the mesa MP and an oxidized region 105b included in the mesa MP and surrounding the non-oxidized region 105a. The region of the active layer 106 corresponding to the non-oxidized region 105a (for example, the central region) becomes the light-emitting region LA. The outer shape (plan view shape) of the non-oxidized region 105a is defined by the inner circumferential shape of the oxidized region 105b. The diameter (average diameter) of the non-oxidized region 105a is defined by the inner diameter (average inner diameter) of the oxidized region 105b. In the oxidation constriction layer 105, the non-oxidized region 105a is also called OA (Optical Aperture). In the oxidative constriction layer 105, the diameter of the non-oxidized region 105a is also called the OA diameter (Optical Aperture Diameter).

[0052] The non-oxidizing region 105a is, for example, located in the central part of the mesa MP in a plan view and functions as a current / light passing region (aperture). The non-oxidizing region 105a includes, for example, a p-type compound semiconductor containing Al (e.g., p-AlGaAs, p-AlAs, etc.). Here, the non-oxidizing region 105a consists of p-AlGaAs (C-doped, 15-20 nm thick) with a high Al composition. The OA diameter is preferably less than or equal to the short axis of the non-oxidizing region 103b1 of the low refractive index layer 103b of the first semiconductor multilayer reflecting mirror 103, which will be described later, and for this reason, the p-Al used in the non-oxidizing region 105a is... ｘ Ga １－ｘ The As layer preferably has an Al composition x (for example, x ≥ 0.9) that is greater than or equal to the Al composition of the non-oxidizing region 103b1. Here, the OA has a substantially circular shape in plan view, and the OA diameter is several μm to more than 10 μm.

[0053] The oxidized region 105b is, for example, a circumferential (e.g., ring-shaped) region in a plan view surrounding the non-oxidized region 105a. The oxidized region 105b is a region with higher resistance and lower refractive index than the non-oxidized region 105a, and functions as a current / light constriction region. The oxidized region 105b is, for example, an oxide containing Al (e.g., Al ｘ O ｙ This includes (etc.). The oxidation region 105b is exposed to the side surface of the mesa MP across its entire outer edge. The oxidation region 105b is provided with the same width across the entire outer edge of the isotropically shaped mesa MP, and does not impart anisotropic stress to the active layer 106.

[0054] Because the mesa portion MP has an isotropic shape, oxidation treatment makes it easier to obtain an isotropic shape (e.g., circular, regular polygon, etc.) in the non-oxidized region 105a, and an effect of suppressing higher-order transverse mode oscillation can be expected.

[0055] Similarly, from the viewpoint of suppressing higher-order transverse mode oscillations, the OA diameter is preferably, for example, 3 to 8 μm, more preferably 5 to 7 μm. Furthermore, it is preferable that the OA is positioned in a location that overlaps with the central part of the non-oxidizing structure NOS of the first semiconductor multilayer film reflector 103, as described later, when viewed from the bottom.

[0056] Furthermore, the mesa diameter, which is the diameter of the mesa portion MP, is preferably 1 to 15 μm, more preferably 2 to 10 μm, added to the OA diameter, taking into consideration the required oxidation width of the oxidation region 105b, the area required for current injection, and the manufacturing margin. For example, in this embodiment, the OA diameter can be 5 μm, the mesa diameter 11 μm, and the short axis length of the non-oxidized structure NOS of the first structure ST1, which will be described later, can be 5.5 μm.

[0057] The oxidative constriction layer 105 is preferably positioned at or near the node of a standing wave generated within the resonator. This suppresses light absorption in the oxidative constriction layer 105.

[0058] As an example, an oxide layer 119 is provided in the first cladding layer 104 of the first and second sidewall portions SWP1 and SWP2, at a position corresponding to the oxidation constriction layer 105. The oxide layer 119 has higher resistance and a lower refractive index than the non-oxidized region 105a. The oxide layer 119 is, as an example, an Al-containing oxide (e.g., Alｘ O ｙ This includes, for example, the oxide layer 119 provided on the first sidewall SWP1 has its entire outer edge exposed to the side surface of the first sidewall SWP1. For example, the oxide layer 119 provided on the second sidewall SWP2 has its entire outer edge exposed to the side surface of the second sidewall SWP2.

[0059] (Active layer) The active layer 106 is, for example, made of a compound semiconductor having a smaller bandgap energy than the first and second cladding layers 104 and 107. The active layer 106 is, for example, made of a GaAs-based compound semiconductor (e.g., GaAs, AlGaAs, InGaAs, GaInAsN, etc.). The active layer 106 may have any of the following structures: quantum well structure, multiple quantum well structure, quantum nanowire structure, or quantum dot structure. The emission wavelength of the active layer 106 is set to, for example, about 700 to 1100 nm. It is preferable to position the active layer 106 at or near the antinode of a standing wave generated in the resonator. This can improve the luminescence efficiency.

[0060] Here, in order to obtain a desired oscillation wavelength (e.g., 940 nm), the active layer 106 uses a quantum well structure such as GaAsP / InGaAs / GaAsP / InGaAs / GaAsP (all undoped, with each layer having a thickness of 10 nm / 7 nm / 8 nm / 7 nm / 10 nm).

[0061] (Second Cladding Layer) The second cladding layer 107 is constructed in the same manner as the first cladding layer 104, except for the conductivity type. For example, it consists of an n-type compound semiconductor, such as n-AlGaAs (Si-doped, approximately 100 nm thick). The "cladding layer" is also called a "spacer layer". The Al composition of the second cladding layer 107 is, for example, 0.3 to 0.5 (for example, 0.4). An oxide constriction layer may also be provided within the second cladding layer 107. When an oxide constriction layer is provided within the second cladding layer 107, the same design principles (Al composition, film thickness) as when an oxide constriction layer 105 is provided within the first cladding layer 104 can be applied, except that the conductivity type of the oxide constriction layer is matched to that of the second cladding layer 107 (i.e., Si-doped n-AlGaAs or n-AlAs is used as the material for the oxide constriction layer).

[0062] (Second Semiconductor Multilayer Mirror) The second semiconductor multilayer mirror 108 (semiconductor DBR) is, as an example, an n-type semiconductor multilayer mirror doped with n-type impurities, having little light absorption and having high reflectivity and conductivity. The multilayer mirror is also called a distributed Bragg reflector (DBR). The second semiconductor multilayer mirror 108 has a structure in which a high refractive index layer and a low refractive index layer having different refractive indices are alternately stacked with an optical thickness of 1 / 4 wavelength of the emission wavelength of the active layer 106. The low refractive index layer is made of a compound semiconductor containing Al (for example, AlGaAs, AlAs, etc.). The high refractive index layer is made of a compound semiconductor (for example, AlGaAs, GaAs, etc.). The low refractive index layer is a high Al composition layer having a higher Al composition than the high refractive index layer. It is preferable that the refractive index difference (Al composition difference) between the high refractive index layer and the low refractive index layer is large. This is because a high reflectivity can be obtained with a small number of pairs.

[0063] Here, an n-AlGaAs layer doped with Si is used for the low refractive index layer of the second semiconductor multilayer mirror 108, and an n-GaAs layer doped with Si (Al composition x = 0) is used for the high refractive index layer. Since the second semiconductor multilayer mirror 108 needs to emit light to the back side (emission surface side) of the substrate 101, it is preferable that the layer structure (composition, thickness, number of pairs, etc.) is set so as to have a higher reflectivity (for example, 99.9% or more) than the first semiconductor multilayer mirror 103.

[0064] The Al used for the low refractive index layer of the second semiconductor multilayer mirror 108 ｘ Ga １－Ｘ As layer preferably has an Al composition x lower (for example, x <0.8) than the non-oxidized region 103b1 of the low refractive index layer 103b of the first semiconductor multilayer mirror 103. It is more preferable that the low refractive index layer of the second semiconductor multilayer mirror 1 is lower in Al composition than the high refractive index layer 103a of the first semiconductor multilayer mirror 103. In the second semiconductor multilayer mirror 108 as well, the high refractive index layer has a lower Al composition x (including x = 0) than the low refractive index layer.

[0065] As described above, by using an AlGaAs layer with a low Al composition in the second semiconductor multilayer reflector 108, oxidation of the second semiconductor multilayer reflector 108 during the oxidation process to form the oxidation constriction layer and the first semiconductor multilayer reflector 103 can be suppressed. During the oxidation process, the entire outer edge of the second semiconductor multilayer reflector 108 is exposed. Therefore, if the second semiconductor multilayer reflector 108 is oxidized, it may cancel out the anisotropic stress caused by the oxidation structure OS described later, and sufficient polarization may not be obtained.

[0066] (Second Contact Layer) The second contact layer 109 is made of an n-type compound semiconductor, for example, an n-GaAs layer. The second contact layer 109 is a semiconductor layer for making ohmic contact between the cathode electrode, which is the second electrode 113, and the second semiconductor multilayer reflector 108, and is a semiconductor layer doped with a high concentration of n-type impurities (for example, Si). The thickness of the second contact layer 109 is, for example, 273 nm.

[0067] (Insulating film) The insulating film 111 is, for example, SiO ２ It is made of an insulator such as SiN or SiON. The insulating film 111 functions as a protective layer covering the mesa portion MP and the first and second sidewall portions SWP1 and SWP2, preventing short circuits and leaks caused by the intrusion of moisture from the outside or the adhesion of metal scraps, etc.

[0068] (First Electrode) The anode electrode, as the first electrode 112, may have a single-layer structure or a multilayer structure. The first electrode 112 is composed of at least one metal (including alloys) selected from the group consisting of, for example, Au, Ag, Pd, Pt, Ni, Ti, V, W, Cr, Al, Cu, Zn, Sn, Ge, and In. If the first electrode 112 has a multilayer structure, it is composed of materials such as Ti / Au, Ti / Al, Ti / Al / Au, Ti / Pt / Au, Ni / Au, Ni / Au / Pt, Ni / Pt, Pd / Pt, Ag / Pd, etc. The first electrode 112 is electrically connected to the anode side of the driver.

[0069] (Second Electrode) The cathode electrode, which serves as the second electrode 113, may have a single-layer structure or a multilayer structure. The second electrode 113 is composed of at least one metal (including alloys) selected from the group consisting of, for example, Au, Ag, Pd, Pt, Ni, Ti, V, W, Cr, Al, Cu, Zn, Sn, Ge, and In. If the second electrode 113 has a multilayer structure, it is composed of materials such as Ti / Au, Ti / Al, Ti / Al / Au, Ti / Pt / Au, Ni / Au, Ni / Au / Pt, Ni / Pt, Pd / Pt, Ag / Pd, AuGe / Ni / Au, etc. The second electrode 113 is electrically connected to the cathode side of the driver. It is also possible to make the second electrode 113 function as part of the upper reflector (metal reflector) together with the second semiconductor multilayer reflector 108.

[0070] (Oxidized structure and non-oxidized structure) Figure 5 is a cross-sectional view of the oxidized structure OS of a surface-emitting laser 10 according to Example 1 of one embodiment of the present technology.

[0071] The oxide structure OS functions as a polarization control structure. The oxide structure OS is provided on the outer periphery of the first structure ST1, as shown in Figures 1, 2, and 5. More specifically, the oxide structure OS is composed of an oxide region 103b2 provided on the outer periphery of at least one (e.g., more) low refractive index layers 103b of the first semiconductor multilayer reflecting mirror 103.

[0072] The oxidation structure OS is circumferential in plan view (preferably circumferential with shape anisotropy in plan view). More specifically, the oxidation region 103b2 of the low refractive index layer 103b included in the oxidation structure OS surrounds the non-oxidized region 103b1 of the low refractive index layer 103b. Here, the plan view shape of the oxidation structure OS is the shape of the outer perimeter of a race track, but any circumferential shape with shape anisotropy in plan view may be, for example, rectangular frame shape, elliptical frame shape, etc. The long axis direction (longitudinal direction) of the oxidation structure OS coincides with the long axis direction (longitudinal direction) of the first structure ST1. Hereinafter, the long axis direction of the oxidation structure OS will also be simply referred to as the "long axis direction," and the short axis direction of the oxidation structure OS will also be simply referred to as the "short axis direction."

[0073] The oxidized structure OS has first and second oxidized regions OP1 and OP2 that sandwich the light-emitting region LA (located in a position corresponding to the non-oxidized region 105a in a plan view) in a direction perpendicular to the longitudinal direction of the first structure ST1 (the direction of the 2-2 line in Figure 3) (see Figures 2 and 5). Each oxidized region consists of at least one (for example, more) oxidized regions 103b2.

[0074] Each of the first and second oxidation regions OP1 and OP2 overlaps with the mesa region MP in at least a portion (for example, a portion) in a plan view. More specifically, each of the first and second oxidation regions OP1 and OP2 overlaps with the oxidation region 105b of the oxidation constriction layer 105 in at least a portion (for example, a portion) in a plan view.

[0075] On the other hand, in a plan view, the third and fourth oxidation regions OP3 and OP4 of the oxidation structure OS, which sandwich the light-emitting region LA in the longitudinal direction of the first structure ST1 (the direction of the 1-1 line in Figure 2), are located away from the mesa region MP in a plan view.

[0076] Here, in the oxidation structure OS, during the oxidation process, the AlGaAs layer and AlAs, which are the material of the low refractive index layer 103b of the first semiconductor multilayer reflector 103, are oxidized (Al ２ O ３ When the material is transformed into the first and second oxidation parts OP1 and OP2, expansion occurs, generating stress near each oxidation part. At this time, the active layer 106 of the mesa part MP, which partially overlaps with each of the first and second oxidation parts OP1 and OP2 aligned in the short axis direction and is separated from the third and fourth oxidation parts OP3 and OP4 aligned in the long axis direction, is subjected to anisotropic stress in the short axis direction, thereby strengthening the polarization component in the long axis direction.

[0077] Here, at least one non-oxidized region 103b1 of the low refractive index layer 103b may have a higher Al composition x (e.g., x ≥ 0.9). A higher Al composition not only lowers the refractive index but also increases the oxidation rate in the oxidation process. Therefore, the stress applied to the active layer 106 (the stress at which polarization characteristics are obtained) can be adjusted by appropriately designing the Al composition, thickness, and combination (number and ratio of low refractive index layers with different Al compositions) of the low refractive index layers.

[0078] The non-oxidized structure NOS, which is the inner circumferential structure of the oxidized structure OS of the first semiconductor multilayer mirror 103, has a planar shape (e.g., a racetrack shape) that is substantially similar to the shape of the oxidized structure OS (see Figure 5). It is preferable that the long axis length of the non-oxidized structure NOS is longer than the diameter of the mesa portion MP. This makes it possible to increase the distance between the third and fourth oxidized portions OP3 and OP4, which are aligned in the long axis direction, and the mesa portion MP, thereby increasing the anisotropic stress in the short axis direction. It is preferable that the short axis length of the non-oxidized structure NOS is 1 to 1.2 times the diameter (OA diameter) of the non-oxidized region 105a of the oxidized constriction layer 105. If the short axis length of the non-oxidized structure NOS is shorter than the diameter of the non-oxidized region 105a, the efficiency of light hitting the oxidized structure OS decreases, and the radial oxidation length (oxidation width, oxidation distance) of the oxidized structure OS becomes longer, requiring extra time for the oxidation treatment. Conversely, if the short-axis length of the non-oxidized structure NOS becomes larger than the above range, it becomes necessary to narrow the allowable oxidation width of the oxidized structure OS or increase the size of the light-emitting element R, making it difficult to secure sufficient anisotropic stress or to increase the density when arranging the surface-emitting lasers 10 in an array.

[0079] (First and second grooves, first and second sidewalls) The first groove T1, for example, has a uniform width throughout the depth direction (preferably 1 to 3 μm, more preferably 1 to 2 μm) so that the distance between the mesa portion MP and the first sidewall portion SWP1 is constant. The second groove T2, for example, has a uniform width throughout the depth direction (preferably 1 to 3 μm, more preferably 1 to 2 μm) so that the distance between the mesa portion MP and the second sidewall portion SWP2 is constant. By having the width of each groove within the above range, it becomes possible to form grooves with different etching depths and mesa-shaped light-emitting portions R simultaneously by dry etching. By making the widths of the first and second grooves T1 and T2 the same, it becomes possible to make the height of the mesa portion MP uniform on the first groove T1 side and the second groove T2 side.

[0080] It is important that the depths of the first and second grooves T1 and T2 are such that the end faces of the material of the oxidative constriction layer 105 (e.g., AlGaAs, AlAs, etc.) are exposed on the side surface of the mesa portion MP. For example, the bottom surfaces of the first and second grooves T1 and T2 may be located within the first semiconductor multilayer mirror 103.

[0081] The first and second sidewall portions SWP1 and SWP2 are used not only for the simultaneous formation of the first and second grooves T1 and T2 and the mesa-shaped light-emitting portion R, but also for pressure distribution when bonding the surface-emitting laser 10 to the electrodes on the mounting substrate (e.g., drive substrate), and for increasing the thermal and electrical contact area of ​​the light-emitting portion R. In the case of the oxide layer 119 within each sidewall portion, it is not a problem if an unoxidized portion remains in the center when insulated by the insulating film 111, but from the viewpoint of reliability, it is preferable that the entire area is oxidized. The entire area of ​​the oxide layer 119 can be oxidized by designing the oxide layer 119 such that the distance from each point to the side surface is smaller than the oxidation width of the oxidation constriction layer 105 (the radial width of the oxidation region 105b). For example, in this embodiment, the long axis length of the light-emitting portion R is about 30 μm, and the length of each sidewall portion in the long axis direction of the light-emitting portion R is about 6 μm, which is twice the oxidation width of the oxidation constriction layer 105, which is 3 μm. Furthermore, although this embodiment shows an example where the side wall portion is approximately arc-shaped in plan view, it is not limited to this, and may be approximately rectangular in shape, for example. However, it is preferable that the width of each groove be uniform, and that the groove-side surface of each side wall portion be shaped to conform to the outer circumferential surface of the mesa portion MP.

[0082] ≪Operation of the Surface-Emitting Laser≫ The operation of the surface-emitting laser 10 will be described below. When the driver's power supply voltage is applied to the surface-emitting laser 10, current flows into the light-emitting element R from the anode side of the driver, through the anode electrode as the first electrode 112 and the first contact layer 102 in that order. The current that flows into the light-emitting element R passes through the non-oxidizing structure NOS of the first semiconductor multilayer reflector 103, is narrowed by the oxidation-constricting layer 105, and is injected into the light-emitting region LA of the active layer 106 via the first cladding layer 104. At this time, the light-emitting region LA emits light, and the light travels back and forth between the first and second semiconductor multilayer reflectors 103 and 108, narrowed by the oxidation-constricting layer 105 and amplified by the active layer 106. When the oscillation conditions are met, the light is emitted as laser light to the back side of the substrate 101. The current injected into the light-emitting region LA flows out to the cathode side of the driver via the second cladding layer 107, the second semiconductor multilayer reflector 108, the second contact layer 109, and the cathode electrode as the second electrode 113, in that order.

[0083] ≪Manufacturing Method for Surface-Emitting Lasers≫ Below, an example of a manufacturing method for surface-emitting lasers 10 will be explained with reference to the flowchart in Figure 6. The overall process is as follows: First, multiple surface-emitting lasers 10 are simultaneously generated on a single wafer (hereinafter referred to as "substrate 101" for convenience) which is the base material for the substrate 101, using a semiconductor manufacturing method with semiconductor manufacturing equipment. Next, the multiple surface-emitting lasers 10, which are a single integrated unit, are separated from each other by dicing (for example, stealth dicing) to obtain chip-shaped surface-emitting lasers 10.

[0084] In the first step S1, a laminate is generated (see Figure 7A (corresponding to the cross-section along line 1-1 in Figure 3) and Figure 7B (corresponding to the cross-section along line 2-2 in Figure 3)). Specifically, an epitaxial crystal growth method such as MOCVD (Metal Organic Chemical Vapor Deposition) is used to generate a laminate by stacking a first contact layer 102, a semiconductor multilayer reflector 103S which is the material for the first semiconductor multilayer reflector 103, a first cladding layer 104 with an oxidized layer 105S (e.g., AlGaAs, AlAs, etc.) inserted into it, an active layer 106, a second cladding layer 107, a second semiconductor multilayer reflector 108, and a second contact layer 109 in this order on a substrate 101 which serves as a growth substrate. When forming the laminate, the raw materials for the compound semiconductor include, for example, methyl-based organometallic gases such as trimethylaluminum (TMAl), trimethylgallium (TMGa), and trimethylindium (TMIn), and arsine (AshH). ３ Using gas, the raw material for the donor impurity is, for example, disilane (Si ２ H ６ ) is used, and as the raw material for acceptor impurities, for example, carbon tetrabromide (CBr) ４ Use ).

[0085] In the next step S2, a mesa M is formed (see Figure 8A (corresponding to the cross-section along line 1-1 in Figure 3) and Figure 8B (corresponding to the cross-section along line 2-2 in Figure 3)). Specifically, first, a resist pattern for forming the mesa M is formed on the laminate by photolithography. Next, the laminate is etched using the resist pattern as a mask, for example, by dry etching. This etching is carried out, for example, until the bottom surface of the etching is located within the first contact layer 102. As a result, the mesa M is formed. After that, the resist pattern is removed.

[0086] In the next step S3, the first and second grooves T1 and T2 are formed (see Figure 9A (corresponding to the cross section along line 1-1 in Figure 3) and Figure 9B (corresponding to the cross section along line 2-2 in Figure 3)). Specifically, first, a resist pattern for forming the first and second grooves T1 and T2 is formed on the laminate on which the mesa M is formed by photolithography. Next, the laminate is etched by dry etching using the resist pattern as a mask. The etching here is carried out until at least the side surface of the oxidized layer 105S is exposed (for example, until the semiconductor multilayer reflector 103S is exposed). As a result, the first and second sidewall portions SWP1 and SWP2 (more precisely, the sidewall portion that becomes the first sidewall portion SWP1 and the sidewall portion that becomes the second sidewall portion SWP2) are formed. After that, the resist pattern is removed. Note that the order of steps S2 and S3 can be reversed.

[0087] In the next step S4, the oxidized constriction layer 105 and the oxidized structure OS are formed (see Figure 10A (corresponding to the cross-section along line 1-1 in Figure 3) and Figure 10B (corresponding to the cross-section along line 2-2 in Figure 3)). Specifically, the mesa M formed in the laminate and the first and second grooves T1 and T2 are exposed to a high-temperature steam atmosphere to selectively oxidize the oxidized layer 105S and the low refractive index layer of the semiconductor multilayer reflector 103S, respectively, at a desired distance from the end face. During this oxidation process, the oxidized layer 105S on each side wall is also oxidized in the same way, forming an oxidized layer 119.

[0088] In the next step S5, the insulating film 111 is formed. Specifically, first, the insulating film 111 is deposited over the entire surface (see Figure 11A (corresponding to the cross-section along line 1-1 in Figure 3) and Figure 11B (corresponding to the cross-section along line 2-2 in Figure 3)). At this time, the insulating film 111 is deposited along the mesa portion MP, the first and second sidewall portions SWP1 and SWP2, and the first contact layer 102. Next, the insulating film 111 on the electrode contact area of ​​the first contact layer 102 and the insulating film 111 on the electrode contact area of ​​the second contact layer 109 are removed by photolithography and etching (see Figure 12A (corresponding to the cross-section along line 1-1 in Figure 3) and Figure 12B (corresponding to the cross-section along line 2-2 in Figure 3)).

[0089] In the next step S6, an anode electrode is formed as the first electrode 112 (see Figure 13A (corresponding to the cross-section along line 1-1 in Figure 3) and Figure 13B (corresponding to the cross-section along line 2-2 in Figure 3)). Specifically, the first electrode 112 is formed on the electrode contact area of ​​the first contact layer 102, for example by the lift-off method, so as to surround the light-emitting portion in a plan view. At this time, for example, vapor deposition or sputtering is used to deposit the electrode material.

[0090] In the final step S7, a cathode electrode is formed as the second electrode 113 (see Figure 14A (corresponding to the cross-section along line 1-1 in Figure 3) and Figure 14B (corresponding to the cross-section along line 2-2 in Figure 3)). Specifically, the second electrode 113 is formed on the mesa portion MP, the first and second sidewall portions SWP1 and SWP2, and the first and second grooves T1 and T2, for example, by the lift-off method. At this time, for example, vapor deposition or sputtering is used to deposit the electrode material.

[0091] Furthermore, steps S2 and S3 may be performed simultaneously, that is, mesas and grooves with different etching depths may be formed simultaneously by utilizing the microloading effect. Alternatively, the order of steps S6 and S7 may be reversed, that is, the first electrode 112 may be formed after the second electrode 113.

[0092] <<Effects of surface-emitting laser and method for manufacturing the surface-emitting laser>> The effects of the surface-emitting laser 10 will be explained below.

[0093] The surface-emitting laser 10 comprises a light-emitting element R including a first structure ST1 and a second structure ST2 having a mesa portion MP provided on the first structure ST1, wherein the second structure ST2 has an active layer 106 having a light-emitting region LA, and the first structure ST1 has an oxide structure OS that imparts anisotropic stress to the active layer 106.

[0094] In the surface-emitting laser 10, the oxide structure OS can be formed relatively easily as a polarization control structure by oxidation treatment.

[0095] As a result, the surface-emitting laser 10 can provide a surface-emitting laser that can suppress the complexity of the process for forming a polarization-controlled structure.

[0096] On the other hand, in the surface-emitting laser described in Patent Document 1, for example, it is necessary to form a grating as a polarization control structure in the mesa portion, which leads to a complicated process for forming the polarization control structure.

[0097] Furthermore, in the surface-emitting laser described in Patent Document 1, for example, a highly reflective semiconductor DBR is placed between the active layer and the grating. As a result, most of the light from the active layer is reflected towards the substrate before reaching the grating, making it difficult to obtain sufficient polarization.

[0098] On the other hand, in the surface-emitting laser 10, polarization is obtained by imparting anisotropic stress to the active layer 106 using the oxidized structure OS, thus enabling stable and sufficient polarization.

[0099] The oxidation structure OS is provided on the outer periphery of the first structure ST1. This allows the oxidation structure OS to be easily formed by oxidation treatment from the outer periphery side of the first structure ST.

[0100] The first structure ST1 has a longitudinal direction in its plan view. This makes it possible to create a difference between the longitudinal distance between the oxide structure OS and the mesa portion MP in a plan view and the distance in a direction perpendicular to the longitudinal direction (for example, the short direction), thereby reliably imparting anisotropic stress to the active layer 106.

[0101] The oxidation structure OS has first and second oxidation parts OP1 and OP2 that sandwich the light-emitting region LA in a direction perpendicular to the longitudinal direction of the first structure ST1 when viewed in plan. This allows sufficient anisotropic stress to be imparted to the active layer 106.

[0102] In a plan view, at least a portion of each of the first and second oxidation sections OP1 and OP2 overlaps with the mesa section MP. This allows sufficient anisotropic stress to be imparted to the active layer 106.

[0103] The oxidized structure OS is circumferential in plan view. This allows the oxidized structure OS to be formed by a general-purpose oxidation treatment that oxidizes the entire outer circumference of the first structure ST.

[0104] The second structure ST2 has an active layer 106, and the mesa portion MP has at least a light-emitting region LA within the active layer 106. This makes it possible to increase the current density of the injected current into the light-emitting region LA.

[0105] The mesa portion MP has an oxidation constriction layer 105 that sets the light-emitting region LA. This allows the oxidation constriction layer 105 to be formed on a relatively small diameter mesa portion MP, thereby shortening the oxidation time during the oxidation process.

[0106] The oxidative constriction layer 105 has a non-oxidized region 105a and an oxidized region 105b surrounding the non-oxidized region 105a, and at least a portion of each of the first and second oxidized regions OP1 and OP2 overlaps with the oxidized region 105b in a plan view. This allows sufficient anisotropic stress to be applied near the light-emitting region LA of the active layer 106.

[0107] The second structure ST2 has sidewalls (for example, first and second sidewalls SWP1 and SWP2) on one and the other side of the mesa portion MP on the first structure ST1 in the longitudinal direction of the first structure ST1. This makes it possible to suppress damage to the mesa portion MP during junction-down mounting to the mounting substrate even if the mesa portion MP has a small diameter, and to ensure sufficient electrical and thermal contact between the entire light-emitting element R and the mounting substrate.

[0108] On the other hand, for example, Japanese Patent Publication No. 2020-155771 discloses a general configuration of a back-side injection-type VCSEL array, in which multiple VCSELs (mesas) formed on a substrate are each joined to a submount or the like via solder. The shape of the mesa is generally cylindrical, and metal electrodes for current injection and heat dissipation are formed at the top of the mesa. If the mesa diameter (cross-sectional area of ​​the cylinder) is small, sufficient electrical and thermal contact cannot be ensured, and there are problems such as breakage due to the pressure when mounting (joining) to the submount. Conversely, if the mesa diameter is large, it becomes difficult to increase the density of the array, resulting in an increase in the size (cost) of the VCSEL array. An oxidation constriction layer is inserted into each mesa to improve efficiency. The oxidation constriction layer is made by oxidizing an AlGaAs layer with a high Al composition in a water vapor atmosphere to make the area other than the center highly resistive (Al ２ O ３ It is formed by oxidation. Since controlling the aperture (the non-oxidized region in the center) diameter of the oxidized constriction layer requires high precision, the oxidation treatment is carried out at a low rate. Therefore, the larger the mesa diameter, the longer the oxidation treatment required to form the oxidized constriction layer, which is undesirable from the standpoint of mass production.

[0109] The mesa portion MP and at least the mesa portion MP of the first and second sidewall portions SWP1 and SWP2 are covered by at least the second electrode 113 from the side opposite to the first structure ST1. This allows for electrical connection between at least the mesa portion MP and the mounting substrate, and also allows for a larger area for the second electrode 113.

[0110] The first and second sidewalls SWP1 and SWP2 are covered by at least the second electrode 113 from the side opposite to the first structure ST1. This ensures sufficient electrical and thermal contact between the light-emitting element R and the mounting substrate.

[0111] A portion of the second electrode 113 is provided via an insulating film 111 in the first groove T1 formed by the first structure ST1, the mesa portion MP, and the first side wall portion SWP1, and in the second groove T2 formed by the first structure ST1, the mesa portion MP, and the second side wall portion SWP2. This improves heat dissipation from the mesa portion MP and also blocks (for example, absorbs) excess light from the mesa portion MP (LED light that did not contribute to laser oscillation) and ambient disturbance light.

[0112] The second electrode 113 may be a bonding electrode that is joined to the mounting substrate via bumps. This ensures sufficient electrical and thermal contact with the mounting substrate.

[0113] <2. Light-emitting device according to Example 2 of one embodiment of the present technology> Figure 15A is a cross-sectional view of the light-emitting device 20 according to Example 2 of one embodiment of the present technology (Part 1, corresponding to Figure 1). Figure 15B is a cross-sectional view of the light-emitting device 20 according to Example 2 of one embodiment of the present technology (Part 2, corresponding to Figure 2).

[0114] As shown in Figures 15A and 15B, the light-emitting device 20 comprises a surface-emitting laser 10 according to Embodiment 1 and a mounting substrate 200 on which the surface-emitting laser 10 is mounted.

[0115] Here, the mounting substrate 200 is a drive substrate having a driver. The mounting substrate 200 includes a substrate 201 and an electrode 202 (e.g., a cathode) provided on the substrate 201.

[0116] The surface-emitting laser 10 is mounted on the mounting substrate 200 using a junction-down (flip-chip) configuration. That is, the second electrode 113 (e.g., cathode electrode) of the surface-emitting laser 10 and the electrode 202 of the mounting substrate 200 are joined via a conductive bump B. The first electrode 112 (e.g., anode electrode) of the surface-emitting laser 10 can be electrically connected to another electrode (e.g., anode) of the mounting substrate 200.

[0117] Materials such as Au, Ag, Cu, and solder can be used for conductive bump B.

[0118] The light-emitting device 20 makes it possible to realize a light-emitting device with polarization controllability that can sufficiently ensure electrical and thermal contact between the surface-emitting laser 10 and the mounting substrate 200, and suppress damage to the mesa portion MP.

[0119] <3. Light-emitting device according to Example 3 of one embodiment of the present technology> Figure 16 is a cross-sectional view (part 1) of the light-emitting device 30 according to Example 3 of one embodiment of the present technology. Figure 17 is a cross-sectional view (part 2) of the light-emitting device 30 according to Example 3 of one embodiment of the present technology. Figure 18 is a schematic plan view of the surface-emitting laser array of the light-emitting device 30 according to Example 3 of one embodiment of the present technology. Figure 16 is a cross-sectional view including the cross-section taken along line 16-16 in Figure 18. Figure 17 is a cross-sectional view including the cross-section taken along line 17-17 in Figure 18.

[0120] As shown in Figures 16 to 18, the light-emitting device 30 comprises a surface-emitting laser array VA in which a plurality of surface-emitting lasers 10 according to Embodiment 1 are arranged in an array, and a mounting substrate 200 on which the surface-emitting laser array VA is mounted.

[0121] As an example, the light-emitting device 30 has a dummy mesa DM on one side of the surface-emitting laser array VA (see Figure 16). As an example, the dummy mesa DM has a layer structure and height similar to that of the light-emitting portion of the surface-emitting laser 10. As an example, the entire surface of the dummy mesa DM is covered with an insulating film 111. The dummy mesa DM is also called a "non-emitting mesa" or "base portion".

[0122] In a surface-emitting laser array VA, for example, multiple surface-emitting lasers 10 are arranged in a two-dimensional array along the xy plane (for example, a matrix arrangement) (see Figure 18). Here, the multiple surface-emitting lasers 10 are arranged such that the longitudinal direction of the first structure ST is aligned with the x direction (the short direction is aligned with the y direction).

[0123] In the surface-emitting laser array VA, each surface-emitting laser 10 shares the substrate 101, the lower part of the first contact layer 102, and the first electrode 112 (see Figures 16 and 17). The first electrode 112 (shared electrode) extends from a position covering the first contact layer 102 between the surface-emitting laser 10 closest to the dummy mesa DM and the dummy mesa DM, through the insulating film 111 to the side and even the top of the dummy mesa DM (see Figure 16). The portion of the first electrode 112 that covers the top of the dummy mesa DM via the insulating film 111 becomes the junction electrode.

[0124] Here, the mounting substrate 200 is a drive substrate having a driver. The mounting substrate 200 includes a substrate 201, an electrode 202A (e.g., an anode) provided on the substrate 201 at a position corresponding to a dummy mesa DM, and a plurality of electrodes 202B (e.g., cathodes) provided on the substrate 201 at a position corresponding to a plurality of surface-emitting lasers 10.

[0125] Each surface-emitting laser 10 is mounted on the mounting substrate 200 using a junction-down (flip-chip) configuration. Specifically, the first electrode 112 (e.g., anode electrode) of the surface-emitting laser 10 and the junction electrode 202A of the mounting substrate 200 are joined via a first conductive bump B1. The second electrode 113 (e.g., cathode electrode) of the surface-emitting laser 10 and the electrode 202B of the mounting substrate 200 are joined via a second conductive bump B2.

[0126] Materials such as Au, Ag, Cu, and solder can be used for each conductive bump.

[0127] The spacing Dx and Dy (see Figure 18) in the x and y directions between the light-emitting elements R of adjacent surface-emitting lasers 10 is greater than the width of the first and second grooves T1 and T2, for example, 5 μm or more. By widening the spacing between the light-emitting elements R, the etching rate of the semiconductor layer can be increased during the dry etching process when forming the light-emitting elements R in a mesa shape, thereby achieving the target etching depth. Conversely, in narrow regions such as the first and second grooves T1 and T2, the etching rate is lower (microloading effect) even when etching is performed under the same process conditions compared to wider regions, thus achieving the target etching depth. By utilizing this microloading effect, it is possible to simultaneously form mesa-shaped light-emitting elements R with a deep target etching depth and first and second grooves T1 and T2 with shallow target etching depths. In addition, the etching rate changes depending on the aperture width and shape of the resist, process conditions (gas type, bias, temperature, pressure, etc.), so the target groove depth and light-emitting element height can be obtained by adjusting these conditions.

[0128] As can be understood from the above, the second electrodes 113 (junction electrodes) on each side wall also play a role in load distribution and thermal / electrical contact, so the diameter of the mesa MP can be made to the minimum size necessary for current injection and anisotropic stress application. When the surface-emitting lasers 10 are arranged in an array, as can be seen by referring to Figure 18, in particular, by reducing the spacing Dy in the short axis direction (y direction) of the light-emitting element R (spacing of the mesa MP in the y direction), the array period Py (pitch) in the short axis direction (y direction) of the light-emitting element R can be reduced, and a surface-emitting laser array in which the mesa MPs are densely arranged in the y direction can be obtained. Furthermore, by reducing the spacing Dy and reducing the diameter of the mesa MPs, the array period Py (pitch) in the short axis direction (y direction) of the light-emitting element R can be reduced even further, and a surface-emitting laser array in which the mesa MPs are densely arranged in the y direction can be obtained. Similarly, by reducing the spacing Dx) of the light-emitting element R in the longitudinal direction (x direction), the array period Px (pitch) of the light-emitting element R in the longitudinal direction (x direction) can be reduced, and a surface-emitting laser array can be obtained in which the mesa elements MP are densely arranged in the x direction, though not as densely as in the y direction. Furthermore, by reducing the spacing Dx and decreasing the diameter of the mesa elements MP, the array period Px (pitch) of the light-emitting element R in the longitudinal direction (x direction) can be reduced even further, and a surface-emitting laser array can be obtained in which the mesa elements MP are densely arranged in the x direction, though not as densely as in the y direction.

[0129] The light-emitting device 30 enables the realization of a light-emitting device equipped with a surface-emitting laser array that can densely arrange surface-emitting lasers 10 with polarization controllability, which can sufficiently ensure electrical and thermal contact between the surface-emitting laser 10 and the mounting substrate 200, and suppress damage to the mesa portion MP.

[0130] <4. Surface-emitting laser according to Example 4 of one embodiment of the present technology> Figure 19 is a cross-sectional view of the surface-emitting laser 40 according to Example 4 of one embodiment of the present technology (Part 1, corresponding to Figure 1). Figure 20 is a cross-sectional view of the surface-emitting laser 40 according to Example 4 of one embodiment of the present technology (Part 2, corresponding to Figure 2).

[0131] As shown in Figures 19 and 20, the surface-emitting laser 40 has a configuration that is generally the same as the surface-emitting laser 10 according to Example 1, except that the relative positions of the oxidative constriction layer 105 and the active layer 106 are reversed.

[0132] In the surface-emitting laser 40, for example, an oxidation-constricting layer 105 is provided within the second cladding layer 107 (for example, an n-AlGaAs layer). Here, the non-oxidized region 105a of the oxidation-constricting layer 105 consists of a compound semiconductor with a high Al composition (for example, n-AlGaAs, n-AlAs, etc.).

[0133] The surface-emitting laser 40 provides effects that are generally similar to those of the surface-emitting laser 10 in Example 1.

[0134] <5. Surface-emitting laser according to Example 5 of one embodiment of the present technology> Figure 21 is a cross-sectional view of the surface-emitting laser 50 according to Example 5 of one embodiment of the present technology (Part 1, corresponding to Figure 1). Figure 22 is a cross-sectional view of the surface-emitting laser 50 according to Example 5 of one embodiment of the present technology (Part 2, corresponding to Figure 2).

[0135] As shown in Figures 21 and 22, the surface-emitting laser 50 has a configuration that is generally the same as the surface-emitting laser 40 according to Example 4, except that the first structure ST1 has a first cladding layer 104, an active layer 106, and a part (lower part) of the second cladding layer 107 in addition to the first semiconductor multilayer reflecting mirror 103.

[0136] In the surface-emitting laser 50, as an example, the bottom surfaces of the first and second grooves T1 and T2 are located within the second cladding layer 107, and the mesa portion MP is composed of the other part (upper part) of the second cladding layer 107, which has an oxide constriction layer 105 inside, a second semiconductor multilayer reflecting mirror 108, and a second contact layer 109.

[0137] Although the surface-emitting laser 50 has slightly lower luminescence efficiency because the active layer 106 is not located within the mesa portion MP, it achieves generally the same effects as the surface-emitting laser 40 in Example 4.

[0138] <6. Surface-emitting laser according to Example 6 of one embodiment of the present technology> Figure 23 is a cross-sectional view of the surface-emitting laser 60 according to Example 6 of one embodiment of the present technology (Part 1, corresponding to Figure 1). Figure 24 is a cross-sectional view of the surface-emitting laser 60 according to Example 6 of one embodiment of the present technology (Part 2, corresponding to Figure 2).

[0139] As shown in Figures 23 and 24, the surface-emitting laser 60 has a configuration that is generally the same as the surface-emitting laser 40 according to Example 1, except that the first structure ST1 has a first cladding layer 104, an active layer 106, a second cladding layer 107, and a part (lower part) of the second semiconductor multilayer reflecting mirror 108, in addition to the first semiconductor multilayer reflecting mirror 103.

[0140] In the surface-emitting laser 60, as an example, the bottom surfaces of the first and second grooves T1 and T2 are located within the second semiconductor multilayer reflecting mirror 108, and the mesa portion MP is composed of the other part (upper part) of the second semiconductor multilayer reflecting mirror 108, which has an oxide constriction layer 105 inside, and the second contact layer 109.

[0141] Although the surface-emitting laser 60 has slightly lower luminescence efficiency because the active layer 106 is not located within the mesa portion MP, it achieves generally the same effects as the surface-emitting laser 40 in Example 4.

[0142] <7. Surface-emitting laser according to Example 7 of one embodiment of the present technology> Figure 25A is a cross-sectional view (1) of the surface-emitting laser 70 according to Example 7 of one embodiment of the present technology. Figure 25B is a cross-sectional view (2) of the surface-emitting laser 70 according to Example 7 of one embodiment of the present technology. Figure 25C is a cross-sectional view (3) of the surface-emitting laser 70 according to Example 7 of one embodiment of the present technology. Figure 26 is a schematic plan view of the surface-emitting laser 70 according to Example 7 of one embodiment of the present technology. Figure 25A is a cross-sectional view taken along the line 25A-25A of Figure 26. Figure 25B is a cross-sectional view taken along the line 25B-25B of Figure 26. Figure 25C is a cross-sectional view taken along the line 25C-25C of Figure 26.

[0143] As shown in Figures 25A, 25B, 25C, and 26, the surface-emitting laser 70 has a configuration that is generally the same as the surface-emitting laser 10 according to Embodiment 1, except that the second structure has a connecting portion that connects the mesa portion MP and the side wall portion.

[0144] In the surface-emitting laser 70, the second structure includes a first connecting portion CP1 that connects the mesa portion MP and the first sidewall portion SWP1, and a second connecting portion CP2 that connects the mesa portion MP and the second sidewall portion SWP2. Here, two of each connecting portion are provided. Each connecting portion has a layer configuration that is generally similar to that of the mesa portion MP and each sidewall portion. The two first connecting portions CP1 define one end and the other end of the first groove T1 in the longitudinal direction (here, the direction in which the arc extends). The two second connecting portions CP2 define one end and the other end of the second groove T2 in the longitudinal direction (here, the direction in which the arc extends). The width of each connecting portion is, for example, 1 to 2 μm.

[0145] With the surface-emitting laser 70, the same effects as the surface-emitting laser 10 according to Example 1 can be obtained, and since the mesa portion MP and each side wall portion are connected via two connection portions, the mechanical strength of the mesa portion MP can be improved.

[0146] <8. Surface-emitting laser according to Example 8 of one embodiment of the present technology> Figure 27A is a cross-sectional view of the surface-emitting laser 80 according to Example 8 of one embodiment of the present technology (Part 1, corresponding to Figure 25A). Figure 27B is a cross-sectional view of the surface-emitting laser 80 according to Example 8 of one embodiment of the present technology (Part 2, corresponding to Figure 25B). Figure 27C is a cross-sectional view of the surface-emitting laser 80 according to Example 8 of one embodiment of the present technology (Part 3, corresponding to Figure 25C).

[0147] In the surface-emitting laser 80, as shown in Figures 27A, 27B, and 27C, one longitudinal end 113b of the second electrode 113 is in contact with the top of the first sidewall SWP1 (in this case, the second contact layer 109), and the other longitudinal end 113c of the second electrode 113 is in contact with the top of the second sidewall SWP2 (in this case, the second contact layer 109).

[0148] This increases the current path from the first electrode 112 through the first contact layer 102, the light-emitting element R, and the second contact layer 109 to the second electrode 113, thereby improving electrical characteristics. Furthermore, it increases the heat dissipation path from the light-emitting element R through the second electrode 113 to the mounting substrate, thereby improving heat dissipation characteristics. For example, if the width of the connection portion is about 1 to 2 μm, the oxidation region 105b of the oxidation constriction layer 105 can wrap around during oxidation, allowing oxidation to spread. Therefore, even when a connection portion is provided, an isotropic aperture (for example, approximately circular) can be obtained.

[0149] <9. Surface-emitting laser according to Example 9 of one embodiment of the present technology> Figure 28A is a cross-sectional view (1) of the surface-emitting laser 90 according to Example 9 of one embodiment of the present technology. Figure 28B is a cross-sectional view (2) of the surface-emitting laser 90 according to Example 9 of one embodiment of the present technology. Figure 28C is a cross-sectional view (3) of the surface-emitting laser 90 according to Example 9 of one embodiment of the present technology. Figure 29 is a schematic plan view of the surface-emitting laser 90 according to Example 9 of one embodiment of the present technology. Figure 28A is a cross-sectional view taken along the line 28A-28A of Figure 29. Figure 28B is a cross-sectional view taken along the line 28B-28B of Figure 29. Figure 28C is a cross-sectional view taken along the line 28C-28C of Figure 29.

[0150] As shown in Figures 28A, 28B, 28C, and 29, the surface-emitting laser 90 has a configuration that is generally the same as the surface-emitting laser 70 according to Embodiment 7, except that the number of connection points connecting the mesa portion MP and each side wall portion is different.

[0151] In the surface-emitting laser 90, the second structure has three first connecting parts CP1 that connect the mesa part MP and the first side wall part SWP1, and three second connecting parts CP2 that connect the mesa part MP and the second side wall part SWP2. Each connecting part has a layer configuration that is generally similar to that of the mesa part MP and each side wall part. Two first grooves T1 are formed by the first side wall part SWP1, the mesa part MP and the three first connecting parts CP1. Two second grooves T2 are formed by the second side wall part SWP2, the mesa part MP and the three second connecting parts CP2.

[0152] With the surface-emitting laser 70, the same effects as the surface-emitting laser 70 according to Example 7 can be obtained, and since the mesa portion MP and each side wall portion are connected via three connection portions, the mechanical strength of the mesa portion MP can be further improved.

[0153] <10. Surface-emitting laser according to Example 10 of one embodiment of the present technology> Figure 30 is a schematic plan view of a surface-emitting laser 100 according to Example 10 of one embodiment of the present technology.

[0154] As shown in Figure 30, the surface-emitting laser 100 has a configuration that is generally the same as the surface-emitting laser 70 according to Embodiment 7, except that the second structure has a different number of connection points connecting the mesa portion MP and each side wall portion.

[0155] In the surface-emitting laser 100, the second structure has one first connecting part CP1 which connects the mesa part MP and the first side wall part SWP1, and one second connecting part CP2 which connects the mesa part MP and the second side wall part SWP2. Each connecting part has the same layer configuration as the mesa part MP and each side wall part. Two first grooves T1 are formed by the first side wall part SWP1, the mesa part MP and one first connecting part CP1. Two second grooves T2 are formed by the second side wall part SWP2, the mesa part MP and one second connecting part CP2.

[0156] In the case of the surface-emitting laser 70, although the degree of improvement in the mechanical strength of the mesa portion MP is inferior because the mesa portion MP and each side wall portion are connected via a single connection portion, the same effect as the surface-emitting laser 70 in Example 7 can be obtained with a simpler configuration.

[0157] <11. Surface-emitting laser according to Example 11 of one embodiment of the present technology> Figure 31 is a cross-sectional view of the surface-emitting laser 110 according to Example 11 of one embodiment of the present technology (Part 1, corresponding to Figure 1). Figure 32 is a cross-sectional view of the surface-emitting laser 110 according to Example 11 of one embodiment of the present technology (Part 2, corresponding to Figure 2).

[0158] The surface-emitting laser 110 has a configuration that is generally the same as the surface-emitting laser 10 according to Example 1, except that it has a multi-junction structure in which a plurality (for example, two) of active layers are stacked, as shown in Figures 31 and 32.

[0159] In the surface-emitting laser 110, a first contact layer 102, a first semiconductor multilayer reflector 103, a first cladding layer 104A (e.g., a p-AlGaAs layer), a first active layer 106A, a second cladding layer 107A (e.g., an n-AlGaAs layer), a tunnel junction layer 115, a third cladding layer 104B (e.g., a p-AlGaAs layer), a second active layer 106B, a fourth cladding layer 107B (e.g., an n-AlGaAs layer), a second semiconductor multilayer reflector 108, and a second contact layer 109 are stacked on the substrate 101 in this order from the substrate 101 side.

[0160] In this configuration, a first oxidative constriction layer 105A is provided within a first cladding layer 104A (e.g., a p-AlGaAs layer), and a second oxidative constriction layer 105B is provided within a third cladding layer 104B (e.g., a p-AlGaAs layer).

[0161] In other words, in the surface-emitting laser 110, a tunnel junction layer 115 is provided between the active layers, and an oxide constriction layer is provided for each active layer. It is preferable that each active layer be positioned at or near the antinode of a standing wave generated in the resonator. It is preferable that each oxide constriction layer be positioned at or near the node of a standing wave generated in the resonator.

[0162] Here too, the bottom surfaces of the first and second grooves T1 and T2 coincide with the interface between the first semiconductor multilayer reflector 103 and the first cladding layer 104A. That is, here the mesa portion MP is composed of the first cladding layer 104A, the first oxide constriction layer 105A, the first active layer 106A, the second cladding layer 107A, the tunnel junction layer 115, the third cladding layer 104B, the second oxide constriction layer 105B, the second active layer 106B, the fourth cladding layer 107B, the second semiconductor multilayer reflector 108, and the second contact layer 109.

[0163] The tunnel junction layer 115 includes p-type semiconductor regions and n-type semiconductor regions stacked on top of each other. Here, the n-type semiconductor region is located on the substrate 101 side (lower side) of the p-type semiconductor region. The p-type semiconductor region is, for example, a p-type highly doped layer (e.g., a p++ GaAs layer, 10 nm thick) doped with a high concentration of p-type impurities (e.g., C). The n-type semiconductor region is, for example, an n-type highly doped layer (e.g., n++ InGaAs, 20 nm thick) doped with a high concentration of n-type impurities (e.g., Te). It is preferable that the tunnel junction layer 115 be located at or near the node of a standing wave generated in the resonator. Due to the action of the tunnel junction layer 115, a current of the same magnitude can be passed through the first and second active layers 106A and 106B.

[0164] The surface-emitting laser 110 enables the realization of a high-power and high-efficiency back-side emission VCSEL that provides the same effects as the surface-emitting laser 10 according to Example 1.

[0165] <12. Surface-emitting laser according to Example 12 of one embodiment of the present technology> Figure 33 is a cross-sectional view (part 1, corresponding to Figure 1) of the surface-emitting laser 120 according to Example 12 of one embodiment of the present technology. Figure 34 is a cross-sectional view (part 2, corresponding to Figure 2) of the surface-emitting laser 120 according to Example 12 of one embodiment of the present technology. Figure 35 is a schematic plan view of the surface-emitting laser 120 according to Example 12 of one embodiment of the present technology. Figure 33 is a cross-sectional view taken along line 33-33 of Figure 35. Figure 34 is a cross-sectional view taken along line 34-34 of Figure 35.

[0166] As shown in Figures 33, 34, and 35, the surface-emitting laser 120 has a configuration that is generally the same as the surface-emitting laser 10 according to Embodiment 1, except that it does not have first and second side wall portions SWP1 and SWP2.

[0167] While the surface-emitting laser 120 is inferior in terms of electrical and thermal contact with the mounting substrate and suppression of damage to the mesa portion MP when junction-down mounting is performed, it has a simple structure and exhibits the same polarization control effect as the surface-emitting laser 10 according to Example 1.

[0168] <13. Surface-emitting laser according to Example 13 of one embodiment of the present technology> Figure 36 is a cross-sectional view (part 1, corresponding to Figure 1) of the surface-emitting laser 130 according to Example 13 of one embodiment of the present technology. Figure 37 is a cross-sectional view (part 2, corresponding to Figure 2) of the surface-emitting laser 130 according to Example 13 of one embodiment of the present technology. Figure 38 is a schematic plan view of the surface-emitting laser 130 according to Example 13 of one embodiment of the present technology. Figure 36 is a cross-sectional view taken along line 36-36 of Figure 38. Figure 37 is a cross-sectional view taken along line 37-37 of Figure 38.

[0169] As shown in Figures 36, 37, and 38, the surface-emitting laser 130 has a configuration that is generally the same as the surface-emitting laser 120 according to Embodiment 12, except that the first electrode 112 is provided on the first structure ST1.

[0170] In the surface-emitting laser 130, the first structure ST1 includes a part (lower part) of the first cladding layer 104 in addition to the first semiconductor multilayer reflecting mirror 103.

[0171] In the surface-emitting laser 130, the mesa portion MP is composed of the other part (upper part) of the first cladding layer 104, the oxidative constriction layer 105, the active layer 106, the second cladding layer 107, the second semiconductor multilayer reflector 108, and the second contact layer 109.

[0172] In the surface-emitting laser 130, the first electrode 112 is provided in a circumferential manner (for example, in a ring shape) surrounding the mesa portion MP at the bottom of the first cladding layer 104, which constitutes the uppermost layer of the first structure ST1.

[0173] The surface-emitting laser 130 provides the same effects as the surface-emitting laser 120 in Example 12, while also reducing the series resistance of the mesa portion MP.

[0174] <14. Surface-emitting laser according to Example 14 of one embodiment of the present technology> Figure 39 is a cross-sectional view (part 1, corresponding to Figure 1) of the surface-emitting laser 140 according to Example 14 of one embodiment of the present technology. Figure 40 is a cross-sectional view (part 2, corresponding to Figure 2) of the surface-emitting laser 140 according to Example 14 of one embodiment of the present technology. Figure 41 is a schematic plan view of the surface-emitting laser 140 according to Example 14 of one embodiment of the present technology. Figure 39 is a cross-sectional view taken along line 39-39 of Figure 41. Figure 40 is a cross-sectional view taken along line 40-40 of Figure 41.

[0175] As shown in Figures 39, 40, and 41, the surface-emitting laser 140 has a configuration that is generally the same as the surface-emitting laser 10 according to Example 1, except that it is a surface-emitting type.

[0176] In the surface-emitting laser 140, the first electrode 112 is the anode electrode, and the second electrode 113 is the cathode electrode. The anode electrode, which is the first electrode 112, has an opening in its central portion 113a that serves as the emission port.

[0177] Here too, the conductivity type of the first contact layer 102, the first semiconductor multilayer reflector 103, the first cladding layer 104, and the oxide constriction layer 105 is p-type, and the conductivity type of the second cladding layer 107, the second semiconductor multilayer reflector 108, and the second contact layer 109 is n-type.

[0178] Even with the surface-emitting laser 140, the reflectivity of the first semiconductor multilayer mirror 103 is set slightly higher than the reflectivity of the second semiconductor multilayer mirror 108.

[0179] In the surface-emitting laser 140, in addition to a semi-insulating substrate and an insulating substrate, a conductive substrate (for example, a p-GaAs substrate) may also be used for the substrate 101.

[0180] The surface-emitting laser 140 is mounted on a mounting substrate (e.g., a drive board, a wiring board, etc.) using a junction-up configuration. In this case, for example, the first and second electrodes 112 and 113 of the surface-emitting laser 140 may be connected to the corresponding electrodes on the mounting substrate via bonding wires.

[0181] The surface-emitting laser 140 provides a surface-emitting VCSEL that exhibits effects generally similar to those of the surface-emitting laser 10 according to Example 1.

[0182] <15. Surface-emitting laser according to Example 15 of one embodiment of the present technology> Figure 42 is a cross-sectional view (part 1, corresponding to Figure 1) of the surface-emitting laser 150 according to Example 15 of one embodiment of the present technology. Figure 43 is a cross-sectional view (part 2, corresponding to Figure 2) of the surface-emitting laser 150 according to Example 15 of one embodiment of the present technology. Figure 44 is a schematic plan view of the surface-emitting laser 150 according to Example 15 of one embodiment of the present technology. Figure 42 is a cross-sectional view taken along line 42-42 of Figure 44. Figure 43 is a cross-sectional view taken along line 43-43 of Figure 44.

[0183] As shown in Figures 42, 43, and 44, the surface-emitting laser 150 has a configuration that is generally the same as the surface-emitting laser 140 according to Example 14, except that it is a back-side electrode type.

[0184] In the surface-emitting laser 150, there is no first contact layer 102 between the substrate 101 and the first semiconductor multilayer reflector 103. Instead, the anode electrode, which serves as the first electrode 112, is provided in a solid form on the back surface of the conductive substrate (e.g., a p-GaAs substrate) serving as the substrate 101.

[0185] The surface-emitting laser 150 is mounted on a substrate, for example, using a junction-up configuration. In this case, for example, the first electrode 112 of the surface-emitting laser 150 may be directly bonded to the corresponding electrode on the substrate, and the second electrode 113 may be connected to the corresponding electrode on the substrate via a bonding wire.

[0186] The surface-emitting laser 150 provides a surface-emitting and back-electrode type VCSEL that exhibits generally the same effects as the surface-emitting laser 10 according to Example 1.

[0187] <16. Surface-emitting laser according to Example 16 of one embodiment of the present technology> Figure 45 is a cross-sectional view (part 1, corresponding to Figure 1) of the surface-emitting laser 160 according to Example 16 of one embodiment of the present technology. Figure 46 is a cross-sectional view (part 2, corresponding to Figure 2) of the surface-emitting laser 160 according to Example 16 of one embodiment of the present technology. Figure 47 is a schematic plan view of the surface-emitting laser 160 according to Example 16 of one embodiment of the present technology. Figure 45 is a cross-sectional view taken along line 45-45 of Figure 47. Figure 46 is a cross-sectional view taken along line 46-46 of Figure 47.

[0188] As shown in Figures 45, 46, and 47, the surface-emitting laser 160 has a configuration that is generally the same as the surface-emitting laser 140 according to Embodiment 14, except that the second electrode 113 is provided only on the mesa portion MP.

[0189] The surface-emitting laser 160 is mounted on a substrate, for example, using a junction-up configuration. In this case, for example, the first and second electrodes 112 and 113 of the surface-emitting laser 140 may be connected to the corresponding electrodes on the substrate via bonding wires.

[0190] The surface-emitting laser 160 provides a surface-emitting VCSEL that exhibits generally the same effects as the surface-emitting laser 10 according to Example 1, while also having a smaller area for the second electrode 113 and being easy to form.

[0191] <17. Surface-emitting laser according to Example 17 of one embodiment of the present technology> Figure 48 is a cross-sectional view (part 1, corresponding to Figure 1) of the surface-emitting laser 170 according to Example 17 of one embodiment of the present technology. Figure 49 is a cross-sectional view (part 2, corresponding to Figure 2) of the surface-emitting laser 170 according to Example 17 of one embodiment of the present technology. Figure 50 is a schematic plan view of the surface-emitting laser 170 according to Example 17 of one embodiment of the present technology. Figure 48 is a cross-sectional view taken along line 48-48 of Figure 50. Figure 49 is a cross-sectional view taken along line 49-49 of Figure 50.

[0192] As shown in Figures 48, 49, and 50, the surface-emitting laser 170 has a configuration that is generally the same as the surface-emitting laser 140 according to Embodiment 14, except that the second structure ST2 does not have first and second side wall portions SWP1 and SWP2.

[0193] The surface-emitting laser 170 is mounted, for example, on a mounting substrate using a junction-up configuration. In this case, for example, each of the first and second electrodes 112 and 113 of the surface-emitting laser 170 may be connected to the corresponding electrode on the mounting substrate via bonding wires.

[0194] The surface-emitting laser 170 provides effects that are generally similar to those of the surface-emitting laser 10 according to Example 1, while also simplifying the second structure ST and providing a surface-emitting VCSEL that has a smaller area but is easy to form.

[0195] <18. Surface-emitting laser according to Example 18 of one embodiment of the present technology> Figure 51 is a cross-sectional view (part 1) of the surface-emitting laser 180 according to Example 18 of one embodiment of the present technology. Figure 52 is a cross-sectional view (part 2) of the surface-emitting laser 180 according to Example 18 of one embodiment of the present technology. Figure 53 is a schematic plan view of the surface-emitting laser 180 according to Example 18 of one embodiment of the present technology. Figure 51 is a cross-sectional view taken along line 51-51 of Figure 53. Figure 52 is a cross-sectional view taken along line 52-52 of Figure 53.

[0196] As shown in Figures 51, 52, and 53, the surface-emitting laser 180 has a configuration that is generally the same as the surface-emitting laser 170 according to Embodiment 17, except that the first electrode 112 is provided on the first structure ST1 (for example, a semiconductor multilayer reflecting mirror 103).

[0197] In the surface-emitting laser 180, the mesa portion MP is composed of a first cladding layer 104, an oxidative constriction layer 105, an active layer 106, a second cladding layer 107, a second semiconductor multilayer reflector 108, and a second contact layer 109.

[0198] In the surface-emitting laser 180, the first electrode 112 is arranged in a circumferential manner (for example, in a ring shape) on the first semiconductor multilayer reflecting mirror 103 so as to surround the mesa portion MP.

[0199] The surface-emitting laser 180 provides the same effects as the surface-emitting laser 170 in Example 17, while also reducing the series resistance of the mesa portion MP.

[0200] <19. Surface-emitting laser array according to Example 19 of one embodiment of the present technology> Figure 54 is a schematic plan view of a surface-emitting laser array 190 according to Example 19 of one embodiment of the present technology.

[0201] The surface-emitting laser array 190 has a configuration that is generally similar to the surface-emitting laser array VA of the light-emitting device 30 according to Embodiment 3, except that, as an example, as shown in Figure 54, a plurality of surface-emitting lasers 10 are arranged in two dimensions such that the longitudinal directions of the light-emitting elements of adjacent surface-emitting lasers 10 in the x and y directions are non-parallel (for example, orthogonal) (for example, the mesa portions MP are arranged in a square grid).

[0202] The surface-emitting laser array 190 makes it possible to equally shorten both the x-direction and y-direction array periods Px and Py of the mesa portion MP, and to provide a surface-emitting laser array that can make the polarization directions of adjacent surface-emitting lasers 10 different (for example, orthogonal).

[0203] <20. Surface-emitting laser array according to Example 20 of one embodiment of the present technology> Figure 55 is a schematic plan view of a surface-emitting laser array 205 according to Example 20 of one embodiment of the present technology.

[0204] The surface-emitting laser array 205 has a configuration that is generally similar to the surface-emitting laser array VA of the light-emitting device 30 according to Embodiment 3, except that, as shown in Figure 55, a plurality of surface-emitting lasers 10 are arranged in two dimensions (for example, the mesa portions MP are arranged in a square grid) such that the longitudinal direction of the light-emitting portion of each surface-emitting laser 10 is tilted at the same angle with respect to the x direction (or y direction).

[0205] The surface-emitting laser array 205 makes it possible to equally shorten both the x-direction and y-direction array periods Px and Py of the mesa portion MP, and to provide a surface-emitting laser array that can align the polarization direction among the surface-emitting lasers 10.

[0206] <21. Surface-emitting laser array according to Example 21 of one embodiment of the present technology> Figure 56 is a schematic plan view of a surface-emitting laser array 210 according to Example 21 of one embodiment of the present technology.

[0207] The surface-emitting laser array 210 has a configuration that is generally similar to the surface-emitting laser array VA of the light-emitting device 30 according to Embodiment 3, except that, as shown in Figure 56, the multiple surface-emitting lasers 10 are arranged in a staggered pattern (for example, the mesa portion MP is also arranged in a staggered pattern).

[0208] The surface-emitting laser array 210 provides generally the same effects as the surface-emitting laser array VA of the light-emitting device 30 according to Example 3.

[0209] <22. Light-emitting device according to Example 22 of one embodiment of the present technology> Figure 57 is a schematic plan view of the surface-emitting laser array of the light-emitting device 220 according to Example 22 of one embodiment of the present technology. Figure 58A is a partial plan view of the surface-emitting laser array of the light-emitting device 220 according to Example 22 of one embodiment of the present technology. Figure 58B is a partial cross-sectional view of the light-emitting device 220 according to Example 22 of one embodiment of the present technology.

[0210] As shown in Figures 57, 58A, and 58B, the light-emitting device 220 has a configuration that is generally the same as the light-emitting device 30 according to Embodiment 3, except that in a surface-emitting laser array, the light-emitting parts of a plurality of surface-emitting lasers 10 include two adjacent light-emitting parts in the longitudinal direction, and the two adjacent light-emitting parts share a side wall as a shared side wall SSW.

[0211] In the surface-emitting laser array of the light-emitting device 220, multiple rows of light-emitting elements, each consisting of multiple (e.g., seven) elements aligned in the x-direction, are arranged in the y-direction (for example, five rows). This allows for a shorter x-direction arrangement period Px of the mesa elements MP. To elaborate, compared to the surface-emitting laser array VA of the light-emitting device 30 according to Embodiment 3, the y-direction spacing Dy and arrangement period Py remain unchanged, but the number of side walls between adjacent light-emitting elements in the longitudinal direction in each row of light-emitting elements has been substantially reduced (to one), allowing for a shorter Px, and enabling the arrangement of the mesa elements MP in a square grid, for example, Px = Py.

[0212] In the surface-emitting laser array of the light-emitting device 220, a second electrode 113 is used as a shared electrode between the light-emitting elements of each row of light-emitting elements, acting as a bonding electrode. That is, the second electrode 113 is provided so as to span two adjacent light-emitting elements of each row of light-emitting elements. This makes it possible to drive multiple light-emitting elements of each row of light-emitting elements simultaneously. Alternatively, the second electrode 113 as a bonding electrode may be separated between the light-emitting elements of each row of light-emitting elements (for example, by providing the second electrode 113 on the mesa portion MP of each light-emitting element), allowing each light-emitting element to be driven independently.

[0213] <23. Light-emitting device according to Example 23 of one embodiment of the present technology> Figure 59 is a schematic plan view of the surface-emitting laser array of the light-emitting device 230 according to Example 23 of one embodiment of the present technology. Figure 60A is a partial plan view of the surface-emitting laser array of the light-emitting device 230 according to Example 23 of one embodiment of the present technology. Figure 60B is a partial cross-sectional view of the light-emitting device 230 according to Example 23 of one embodiment of the present technology.

[0214] As shown in Figures 59, 60A, and 60B, the light-emitting device 230 has a configuration that is generally the same as the light-emitting device 220 according to Embodiment 22, except that a second electrode 113 is provided for each light-emitting element in each row of light-emitting elements, and a recess D is provided in the shared side wall SSW.

[0215] In the surface-emitting laser array of the light-emitting device 230, a second electrode 113 is provided as a bonding electrode for each light-emitting element in each row of light-emitting elements, and each light-emitting element can be driven independently. Specifically, the second electrodes 113 of two adjacent light-emitting elements in a row of light-emitting elements may be provided on a shared side wall SSW in an electrically isolated state (see Figure 60A).

[0216] When multiple electrically isolated second electrodes 113 are provided on the shared sidewall SSW in this manner, it becomes difficult to narrow the width of the shared sidewall SSW, while widening the width of the shared sidewall SSW may cause a non-oxidized region to form in the center of the oxide layer 119 within the shared sidewall SSW. Therefore, in the light-emitting device 230, a recess D having a depth approximately the same as the depth of the first and second grooves T1 and T2 is provided in the shared sidewall SSW. This allows oxidation to be carried out from the end face of the oxidized layer (material of the oxide layer 119) of the shared sidewall SSW exposed in the recess D, thereby forming the oxide layer 119. As a result, the width of the shared sidewall SSW can be widened to a degree that secures an area capable of providing multiple electrically isolated second electrodes 113. Here, the recess D is provided in the center of the shared sidewall SSW, but a groove that divides the shared sidewall SSW may be provided, or a notch may be provided in the short-side direction of the light-emitting part of the shared sidewall SSW.

[0217] <24. Light-emitting device according to Example 24 of one embodiment of the present technology> Figure 61 is a cross-sectional view of a light-emitting device 240 according to Example 24 of one embodiment of the present technology.

[0218] The light-emitting device 240 has a configuration that is generally the same as the light-emitting device 30 according to Embodiment 3, except that a lens structure 101a is formed on the back surface of the substrate 101 to control the emission direction and / or radiation angle of each surface-emitting laser 10, as shown in Figure 61.

[0219] The light-emitting device 240 allows for the control of the emission direction and / or radiation angle of each surface-emitting laser 10 without increasing the number of parts.

[0220] <25. Modifications of the Technology> The technology is not limited to the embodiments of the above embodiment and can be modified as appropriate.

[0221] (Modification of Example 5) For example, as shown in Figure 62 (corresponding to Figure 1) and Figure 63 (corresponding to Figure 2), the surface-emitting laser 50M according to a modification of Example 5 may have a semiconductor layer 117 having an oxide structure OS.

[0222] In the surface-emitting laser 50M, the first semiconductor multilayer reflecting mirror 103 does not have an oxide structure OS.

[0223] The semiconductor layer 117 is provided, for example, within the first cladding layer 104. The semiconductor layer 117 consists of a non-oxidizing portion 117a made of a p-type compound semiconductor (for example, p-AlGaAs, p-AlAs, etc. with a high Al composition) and an insulator (for example, Al) surrounding the non-oxidizing portion 117a. ２ O ３ It has an oxide portion 117b made of an oxide such as a ion. The semiconductor layer 117 is preferably placed at or near a node of a standing wave generated in the resonator, because it can suppress light absorption in the semiconductor layer 117.

[0224] The surface-emitting laser 50M provides effects that are generally similar to those of the surface-emitting laser 50 in Example 5.

[0225] In addition, in the surface-emitting laser 50M, the first semiconductor multilayer reflecting mirror 103 may also be provided with an oxide structure OS, similar to the surface-emitting laser 50.

[0226] (Modified Example 6) For example, as shown in Figure 64 (corresponding to Figure 1) and Figure 65 (corresponding to Figure 2), the surface-emitting laser 60M according to a modified example of Example 6 may have a semiconductor layer 117 having an oxide structure OS.

[0227] In the surface-emitting laser 60M, the first semiconductor multilayer reflecting mirror 103 does not have an oxide structure OS.

[0228] The semiconductor layer 117 is provided, for example, within the second cladding layer 107. The semiconductor layer 117 consists of a non-oxidizing portion 117a made of an n-type compound semiconductor (for example, n-AlGaAs, n-AlAs, etc. with a high Al composition) and an insulator (for example, Al) surrounding the non-oxidizing portion 117a. ２ O ３ It has an oxide portion 117b made of an oxide such as a ion. The semiconductor layer 117 is preferably placed at or near a node of a standing wave generated in the resonator, because it can suppress light absorption in the semiconductor layer 117.

[0229] The surface-emitting laser 60M provides effects that are generally similar to those of the surface-emitting laser 60 in Example 6.

[0230] In addition, in the surface-emitting laser 60M, the first semiconductor multilayer film reflecting mirror 103 may also be provided with an oxide structure OS, similar to the surface-emitting laser 60.

[0231] (Modification 1 of Example 1) For example, as shown in Figure 66 (corresponding to Figure 1), the surface-emitting laser 10M1 according to Modification 1 of Example 1 may not have to have one of the first and second sidewall portions SWP1 and SWP2 (for example, the second sidewall portion SWP2).

[0232] (Modification of Example 7) For example, as shown in Figure 67 (corresponding to Figure 3), the surface-emitting laser 70 according to a modification of Example 7 does not necessarily have a connecting portion (for example, a second connecting portion CP2) that connects one of the first and second sidewall portions SWP1 and SWP2 (for example, the second sidewall portion SWP2) to the mesa portion MP.

[0233] (Modification 2 of Example 1) Figure 68 is a cross-sectional view (part 1) of a surface-emitting laser 10M2 according to modification 2 of Example 1 of one embodiment of the present technology. Figure 69 is a cross-sectional view (part 2) of a surface-emitting laser 10M2 according to modification 2 of Example 1 of one embodiment of the present technology. Figure 70 is a schematic plan view of a surface-emitting laser 10M2 according to modification 2 of Example 1 of one embodiment of the present technology. Figure 68 is a cross-sectional view taken along line 68-68 of Figure 70. Figure 69 is a cross-sectional view taken along line 69-69 of Figure 70.

[0234] As shown in Figures 68, 69, and 70, the surface-emitting laser 10M2 does not have a mesa-shaped light-emitting element R, and instead has an oxide structure OS (here only the first and second oxide sections OP1 and OP2) within the first structure ST1. In the surface-emitting laser 10M2, there is no first contact layer 102, and the oxide constriction layer 105 is provided within the second cladding layer 107 (for example, the p-AlGaAs layer).

[0235] In the surface-emitting laser 10M2, the light-emitting element R is provided with first and second grooves T1 and T2 (see Figure 68) that define the longitudinal outer edge of the first structure ST1 of the mesa MP, and third and fourth grooves T3 and T4 (see Figure 69) that define the short outer edge of the first structure ST2. Here, the first and second grooves T1 and T2 penetrate the active layer 106, and the bottom surfaces of the first and second grooves T1 and T2 are located on the substrate 101 side of the active layer 106 (for example, within the first cladding layer 104) (see Figure 68). The bottom surfaces of the third and fourth grooves T3 and T4 are located, for example, at the interface between the substrate 101 and the first semiconductor multilayer reflector 103 or within the substrate 101, so as to expose at least a portion of the side surface of the first semiconductor multilayer reflector 103 (see Figure 69). In other words, the depth of the third and fourth grooves T3 and T4 is greater than the depth of the first and second grooves T1 and T2. Here, the width of the third and fourth grooves T3 and T4 is greater than the width of the first and second grooves T1 and T2, making it possible to form the first to fourth grooves T1, T2, T3, and T4 simultaneously, for example, by utilizing the microloading effect. Note that when the first and second grooves T1 and T2 and the third and fourth grooves T3 and T4 are formed separately, the relative widths of the first and second grooves T1 and T2 and the third and fourth grooves T3 and T4 can be arbitrary.

[0236] Here, the second electrode 113 is the anode electrode, and the two first electrodes 112A and 112B are cathode electrodes. The cathode electrode as the first electrode 112A has a first contact electrode 112a1 provided on the bottom surface of the first groove T1, an intermediate portion extending vertically surrounded by an insulating film 111 covering the side surface of the first groove T1, and another end portion 112b1 as a bonding electrode that extends from the opening of the first groove T1 to the side opposite to the mesa MP side via the insulating film 111. The cathode electrode as the first electrode 112B has a second contact electrode 112a2 provided on the bottom surface of the second groove T2, an intermediate portion extending vertically surrounded by an insulating film 111 covering the side surface of the second groove T2, and another end portion 112b2 as a bonding electrode that extends from the opening of the second groove T2 to the side opposite to the mesa MP side via the insulating film 111.

[0237] (Modification 3 of Example 1) For example, as shown in Figure 71 (corresponding to Figure 1) and Figure 72 (corresponding to Figure 3), the bottom surfaces of the first and second grooves T1 and T2 may be located within the first semiconductor multilayer reflecting mirror 103.

[0238] (Modification 4 of Example 1) For example, as shown in Figure 73 (corresponding to Figure 1) and Figure 74 (corresponding to Figure 3), the connecting portions 113d and 113e of the second electrode 113 may be directly provided in the first and second grooves T1 and T2. In the surface-emitting laser 10M4, ion implantation regions IIA surrounding the light-emitting region LA are provided in the mesa portion MP and the first and second sidewall portions SWP1 and SWP2 of the second structure ST2. The ion implantation region IIA surrounds each of the first and second grooves T1 and T2. Here, the bottom surfaces of the first and second grooves T1 and T2 are located within the first cladding layer 104. The ion implantation depth of the ion implantation region IIA is deeper than the bottom surfaces of the first and second grooves T1 and T2 (for example, within the first cladding layer 104). Examples of ion species in the ion implantation region IIA include H ions and B ions. Alternatively, the luminescence region of the active layer 106 may be set by ion implantation region IIA without providing the oxidative constriction layer 105.

[0239] (Modification of Example 11) For example, as shown in Figure 75 (corresponding to Figure 1) and Figure 76 (corresponding to Figure 3), the surface-emitting laser 110M according to a modification of Example 11 may have a first active layer 106A in the first structure ST1 and a second active layer 106B in the second structure ST2.

[0240] For example, in the surface-emitting lasers according to each of the above embodiments and modifications, in addition to the oxidation region 103b2 on the outer periphery of the low refractive index layer 103b of the first semiconductor multilayer reflector 103, the outer periphery of the high refractive index layer 103a may also be an oxidation region of the oxidation structure OS.

[0241] For example, in the surface-emitting lasers according to each of the above embodiments and modifications, the first contact layer 102, the first and second cladding layers 104 and 107, the oxidative constriction layer 105, and the second contact layer 109 are not essential.

[0242] In the above embodiments and modifications, surface-emitting lasers mainly using GaAs-based materials (materials lattice-matched to GaAs) have been described. However, this technology is not limited to these and can also be applied to surface-emitting lasers using InP-based, GaN-based, and other materials. For example, in the case of an InP-based laser, the semiconductor multilayer mirror may contain AlGaInAs, such as InP / AlGaInAs or AlInAs / AlGaInAs. The active layer may consist of, for example, an AlGaInAs / AlGaInAs multiple quantum well layer.

[0243] In other words, the surface-emitting laser related to this technology can use any material with an emission wavelength included in the wavelength band of 200 to 2000 nm.

[0244] For example, the surface-emitting lasers according to each of the above embodiments and modifications may have, in addition to a semiconductor multilayer film mirror, at least one of the lower mirror and the upper mirror may be a mirror composed of one or more types selected from semiconductors, dielectrics, and metals, or a combination of two or more types.

[0245] In the surface-emitting lasers according to each of the above embodiments and modifications, the conductivity types (p-type and n-type) of the upper and lower active layer 106 may be reversed. However, in this case, the relative positions of the anode electrode and the cathode electrode must also be reversed.

[0246] Some of the configurations of the surface-emitting lasers according to each of the above embodiments and their respective modifications may be combined within a range that is not contradictory to one another.

[0247] In each of the above embodiments and modifications, the arrangement, material, conductivity type, thickness, width, numerical values, shape, size, etc., of each layer constituting the surface-emitting laser can be appropriately changed within the range in which it functions as a surface-emitting laser. For example, the composition, dopants, thickness, and arrangement of some layers described above are just examples.

[0248] <26. Examples of Application to Electronic Devices> The technology relating to this disclosure (this technology) can be applied to various products (electronic devices). For example, the technology relating to this disclosure may be implemented as a device mounted on any type of mobile device such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility devices, airplanes, drones, ships, and robots, or on low-power devices (e.g., smartphones, smartwatches, tablets, mice, laptops, etc.).

[0249] The surface-emitting laser related to this technology can be applied, for example, as a light source for devices that form or display images using light (e.g., printers, copiers, projectors, head-mounted displays, head-up displays, etc.).

[0250] <27. Example of applying a surface-emitting laser to a distance measuring device> Below, an example of the application of the surface-emitting laser 10 according to Embodiment 1 of one embodiment of this technology will be described.

[0251] Figure 77 shows an example of the schematic configuration of a distance measuring device 1000 (distance measuring device) equipped with a surface-emitting laser 10, as an example of electronic equipment related to this technology. The distance measuring device 1000 measures the distance to a subject S using the TOF (Time Of Flight) method. The distance measuring device 1000 is equipped with a surface-emitting laser 10. The distance measuring device 1000 includes, for example, a surface-emitting laser 10, a light receiving device 125, lenses 128 and 138, a signal processing unit 145, a control unit 155, a display unit 165, and a storage unit 175.

[0252] The light receiving device 125 receives light emitted from the surface-emitting laser 10 and reflected by the object S. In other words, the light receiving device 125 detects the light reflected by the object S. Lens 128 is a lens for aligning the light emitted from the surface-emitting laser 10, and is, for example, a collimating lens. Lens 138 is a lens for focusing the light reflected by the object S and guiding it to the light receiving device 125, and is, for example, a focusing lens.

[0253] The signal processing unit 145 is a circuit for generating a signal corresponding to the difference between the signal input from the light receiving device 125 and the reference signal input from the control unit 155. The control unit 155 is configured to include, for example, a Time to Digital Converter (TDC). The reference signal may be a signal input from the control unit 155, or it may be an output signal from a detection unit that directly detects the output of the surface-emitting laser 10. The control unit 155 is a processor that controls, for example, the surface-emitting laser 10, the light receiving device 125, the signal processing unit 145, the display unit 165, and the storage unit 175. The control unit 155 is a circuit for measuring the distance to the subject S based on the signal generated by the signal processing unit 145. The control unit 155 generates a video signal for displaying information about the distance to the subject S and outputs it to the display unit 165. The display unit 165 displays information about the distance to the subject S based on the video signal input from the control unit 155. The control unit 155 stores the information about the distance to the subject S in the storage unit 175.

[0254] In this application example, instead of the surface-emitting laser 10, any of the following can be applied to the distance measuring device 1000: surface-emitting lasers 10M1, 10M2, 10M3, 10M4, light-emitting devices 20, 30, surface-emitting lasers 40, 50, 60, 70, 70M, 80, 90, 100, 110, 110M, 120, 130, 140, 150, 170, 180, surface-emitting laser arrays 190, 205, 210, or light-emitting devices 220, 230, 240.

[0255] <28. Example of mounting a distance measuring device on a mobile body> Figure 78 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile body control system to which the technology described herein can be applied.

[0256] The vehicle control system 12000 comprises a plurality of electronic control units connected via a communication network 12001. In the example shown in Figure 78, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. The functional configuration of the integrated control unit 12050 is shown in the figure, which includes a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network interface 12053.

[0257] The drivetrain control unit 12010 controls the operation of devices related to the vehicle's drivetrain according to various programs. For example, the drivetrain control unit 12010 functions as a control device for a drivetrain generating device that generates driving force for the vehicle, such as an internal combustion engine or a drive motor; a drivetrain transmission mechanism that transmits driving force to the wheels; a steering mechanism that adjusts the steering angle of the vehicle; and a braking device that generates braking force for the vehicle.

[0258] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window system, or various lamps such as headlights, reverse lights, brake lights, turn signals, or fog lights. In this case, the body system control unit 12020 may receive radio waves transmitted from a portable device that replaces a key or signals from various switches. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock system, power window system, lamps, etc.

[0259] The external information detection unit 12030 detects information from outside the vehicle equipped with the vehicle control system 12000. For example, a distance measuring device 12031 is connected to the external information detection unit 12030. The distance measuring device 12031 includes the distance measuring device 1000 described above. The external information detection unit 12030 causes the distance measuring device 12031 to measure the distance to an object outside the vehicle (subject S) and acquires the distance data obtained thereby. Based on the acquired distance data, the external information detection unit 12030 may perform object detection processing for people, cars, obstacles, signs, etc.

[0260] The in-vehicle information detection unit 12040 detects information inside the vehicle. The in-vehicle information detection unit 12040 is connected to, for example, a driver status detection unit 12041 that detects the driver's state. The driver status detection unit 12041 includes, for example, a camera that captures images of the driver, and the in-vehicle information detection unit 12040 may calculate the driver's level of fatigue or concentration, or determine whether the driver is drowsy, based on the detection information input from the driver status detection unit 12041.

[0261] The microcomputer 12051 can calculate control target values ​​for the drive force generator, steering mechanism, or braking device based on information inside and outside the vehicle acquired by the external information detection unit 12030 or the internal information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing ADAS (Advanced Driver Assistance System) functions, including vehicle collision avoidance or impact mitigation, following driving based on distance between vehicles, maintaining vehicle speed, vehicle collision warning, or vehicle lane departure warning.

[0262] Furthermore, the microcomputer 12051 can perform cooperative control for purposes such as autonomous driving, where the vehicle drives autonomously without driver intervention, by controlling the drive force generating device, steering mechanism, or braking device, etc., based on information about the vehicle's surroundings acquired by the external information detection unit 12030 or the internal information detection unit 12040.

[0263] Furthermore, the microcomputer 12051 can output control commands to the body system control unit 12020 based on external information acquired by the external information detection unit 12030. For example, the microcomputer 12051 can control the headlights according to the position of a preceding or oncoming vehicle detected by the external information detection unit 12030, and perform coordinated control aimed at reducing glare, such as switching from high beams to low beams.

[0264] The audio-image output unit 12052 transmits at least one of audio and image output signals to an output device capable of visually or audibly notifying information to the vehicle's occupants or to those outside the vehicle. In the example shown in Figure 78, the output devices are exemplified as an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an onboard display and a head-up display.

[0265] Figure 79 shows an example of the installation location of the distance measuring device 12031.

[0266] In Figure 79, the vehicle 12100 has distance measuring devices 12101, 12102, 12103, 12104, and 12105 as a distance measuring device 12031.

[0267] Distance measuring devices 12101, 12102, 12103, 12104, and 12105 are installed, for example, on the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield inside the vehicle 12100. Distance measuring device 12101 installed on the front nose and distance measuring device 12105 installed on the upper part of the windshield inside the vehicle mainly acquire data in front of the vehicle 12100. Distance measuring devices 12102 and 12103 installed on the side mirrors mainly acquire data to the sides of the vehicle 12100. Distance measuring device 12104 installed on the rear bumper or back door mainly acquires data behind the vehicle 12100. The forward data acquired by distance measuring devices 12101 and 12105 is mainly used for detecting preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, etc.

[0268] Figure 79 shows an example of the detection ranges of distance measuring devices 12101 to 12104. Detection range 12111 indicates the detection range of distance measuring device 12101 installed on the front nose, detection ranges 12112 and 12113 indicate the detection ranges of distance measuring devices 12102 and 12103 installed on the side mirrors, respectively, and detection range 12114 indicates the detection range of distance measuring device 12104 installed on the rear bumper or back door.

[0269] For example, the microcomputer 12051, based on distance data obtained from distance measuring devices 12101 to 12104, can determine the distance to each object within the detection range 12111 to 12114 and the temporal change of this distance (relative speed to the vehicle 12100). In particular, it can extract the nearest object on the vehicle 12100's path that is traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or more) as the preceding vehicle. Furthermore, the microcomputer 12051 can set a predetermined distance to be maintained before the preceding vehicle and perform automatic braking control (including follow-and-stop control) and automatic acceleration control (including follow-and-start control), etc. In this way, cooperative control aimed at autonomous driving, where the vehicle drives autonomously without driver intervention, can be performed.

[0270] For example, the microcomputer 12051 can use distance data obtained from distance measuring devices 12101 to 12104 to classify and extract three-dimensional object data related to three-dimensional objects, such as motorcycles, passenger cars, large vehicles, pedestrians, utility poles, and other three-dimensional objects, and use this data for automatic obstacle avoidance. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the degree of risk of collision with each obstacle. If the collision risk is above a set value and there is a possibility of collision, the microcomputer 12051 can provide driving assistance to avoid a collision by outputting a warning to the driver via the audio speaker 12061 or display unit 12062, or by performing forced deceleration or evasive steering via the drive system control unit 12010.

[0271] The above describes an example of a mobile control system to which the technology described herein may be applied. The technology described herein may be applied to the distance measuring device 12031 among the configurations described above.

[0272] Furthermore, this technology can also take the following configurations: (1) A surface-emitting laser comprising a first structure and a second structure having a mesa portion provided on the first structure, wherein the first structure and / or the second structure have an active layer having a light-emitting region, and the first structure has an oxidation structure that imparts anisotropic stress to the active layer. (2) The surface-emitting laser according to (1), wherein the oxidation structure is provided on the outer periphery or inside the first structure. (3) The surface-emitting laser according to (1) or (2), wherein the first structure has a longitudinal shape in plan view. (4) The surface-emitting laser according to any one of (1) to (3), wherein the oxidation structure has first and second oxidation portions that sandwich the light-emitting region in plan view. (5) The surface-emitting laser according to (4), wherein each of the first and second oxidation portions overlaps the mesa portion in plan view at least in part. (6) The surface-emitting laser according to any one of (1) to (5), wherein the oxidation structure is circumferential in plan view. (7) The surface-emitting laser according to any one of (1) to (6), wherein the second structure has the active layer, and the mesa portion has at least the light-emitting region of the active layer. (8) The surface-emitting laser according to any one of (1) to (7), wherein the mesa portion has an oxidation constriction layer that sets up the light-emitting region. (9) The surface-emitting laser according to any one of (4) to (8), wherein the mesa portion has an oxidation constriction layer that sets up the light-emitting region, and the oxidation constriction layer has a non-oxidized region and an oxidation region surrounding the non-oxidized region, and each of the first and second oxidation portions overlaps with the oxidation region in plan view by at least a portion thereof. (10) The surface-emitting laser according to any one of (3) to (9), wherein the second structure has sidewalls on one side and / or the other side of the mesa portion in the longitudinal direction of the first structure. (11) The surface-emitting laser according to (10), wherein the second structure comprises a first side wall portion provided on one side as the side wall portion, and a second side wall portion provided on the other side as the side wall portion. (12) The surface-emitting laser according to (10) or (11), wherein the second structure comprises a connecting portion connecting the mesa portion and the side wall portion.(13) The surface-emitting laser according to (12), wherein the second structure comprises: a first side wall portion provided on one side as the side wall portion; a second side wall portion provided on the other side as the side wall portion; a first connecting portion connecting the mesa portion and the first side wall portion; and a second connecting portion connecting the mesa portion and the second side wall portion. (14) The surface-emitting laser according to any one of (10) to (13), wherein at least the mesa portion of the mesa portion and the side wall portion is covered with at least an electrode from the side opposite to the first structure. (15) The surface-emitting laser according to (14), wherein the side wall portion is covered with at least the electrode from the side opposite to the first structure. (16) The surface-emitting laser according to (14) or (15), wherein a part of the electrode is provided directly or via an insulating film in a groove formed by the first structure, the mesa portion and the side wall portion. (17) The surface-emitting laser according to any one of (14) to (16), wherein the electrode is a bonding electrode that is bonded to a mounting substrate via bumps. (18) A surface-emitting laser array comprising a plurality of surface-emitting lasers, each including a light-emitting portion comprising a first structure and a second structure having a mesa portion provided on the first structure, wherein the first structure and / or the second structure have an active layer having an emitting region, and the first structure has an oxidation structure that imparts anisotropic stress to the active layer. (19) The surface-emitting laser array according to (18), wherein the first structure of the plurality of surface-emitting lasers has a longitudinal direction in plan view. (20) The surface-emitting laser array according to (19), wherein the plurality of surface-emitting lasers are arranged such that the longitudinal directions of two adjacent surface-emitting lasers are parallel or perpendicular to each other. (21) The surface-emitting laser array according to (19), wherein the light-emitting portion of the plurality of surface-emitting lasers includes two adjacent light-emitting portions in the longitudinal direction, and the two adjacent light-emitting portions share the side wall portion as a shared side wall. (22) The surface-emitting laser array according to (21), wherein an electrode covering the second structure is provided for each of the light-emitting portions. (23) The surface-emitting laser array according to (21), wherein an electrode covering the second structure is provided so as to span the two adjacent light-emitting portions.(24) A surface-emitting laser according to any one of (1) to (23), wherein the first structure has a semiconductor multilayer reflecting mirror.

[0273] 10, 10M1, 10M2, 10M3, 10M4, 40, 50, 60, 70, 70M, 80, 90, 100, 110, 110M, 120, 130, 140, 150, 170, 180: Surface-emitting laser VA, 190, 205, 210: Surface-emitting laser array 101: Substrate 103: First semiconductor multilayer reflector (first structure) 105, 105A, 105B: Oxidation constriction layer 105a: Non-oxidized region 105b: Oxidized region 113: First electrode (electrode) R: Light-emitting element MP: Mesa region OS: Oxidation structure OP1: First oxidation region OP2: Second oxidation region LA: Light-emitting region SWP1: First sidewall region (sidewall region) SWP2: Second side wall section (side wall section) CP1: First connection section (connection section) CP2: Second connection section (connection section) SSW: Shared side wall ST1: First structure ST2: Second structure

Claims

1. A surface-emitting laser comprising a light-emitting portion including a first structure and a second structure having a mesa portion provided on the first structure, wherein the first structure and / or the second structure have an active layer having a light-emitting region, and the first structure has an oxidation structure that imparts anisotropic stress to the active layer.

2. The surface-emitting laser according to claim 1, wherein the oxidation structure is provided on the outer periphery or inside the first structure.

3. The surface-emitting laser according to claim 1, wherein the first structure has a longitudinal direction in plan view.

4. The surface-emitting laser according to claim 1, wherein the oxidation structure has first and second oxidation portions that sandwich the light-emitting region in a plan view.

5. The surface-emitting laser according to claim 4, wherein at least a portion of each of the first and second oxidation portions overlaps with the mesa portion in a plan view.

6. The surface-emitting laser according to claim 3, wherein the oxidation structure is circumferential in plan view.

7. The surface-emitting laser according to claim 1, wherein the second structure has the active layer, and the mesa portion has at least the light-emitting region of the active layer.

8. The surface-emitting laser according to claim 1, wherein the mesa portion has an oxidative constriction layer that sets the light-emitting region.

9. The surface-emitting laser according to claim 4, wherein the mesa portion has an oxidation constriction layer that sets the light-emitting region, the oxidation constriction layer has a non-oxidized region and an oxidation region surrounding the non-oxidized region, and each of the first and second oxidation portions overlaps with the oxidation region in plan view, at least a portion of which overlaps.

10. The surface-emitting laser according to claim 3, wherein the second structure has sidewalls on one and / or the other side of the mesa portion in the longitudinal direction of the first structure.

11. The surface-emitting laser according to claim 10, wherein the second structure comprises a first side wall portion provided on one side and a second side wall portion provided on the other side.

12. The surface-emitting laser according to claim 10, wherein the second structure has a connecting portion that connects the mesa portion and the side wall portion.

13. The surface-emitting laser according to claim 12, wherein the second structure comprises: a first side wall portion provided on one side as the side wall portion; a second side wall portion provided on the other side as the side wall portion; a first connecting portion connecting the mesa portion and the first side wall portion; and a second connecting portion connecting the mesa portion and the second side wall portion.

14. The surface-emitting laser according to claim 10, wherein at least the mesa portion of the mesa portion and the side wall portion is covered with at least an electrode from the side opposite to the first structure side.

15. The surface-emitting laser according to claim 14, wherein the side wall portion is covered by at least the electrode from the side opposite to the first structure side.

16. The surface-emitting laser according to claim 14, wherein a portion of the electrode is provided directly or via an insulating film in a groove formed by the first structure, the mesa portion, and the side wall portion.

17. The surface-emitting laser according to claim 14, wherein the electrode is a bonding electrode that is bonded to a mounting substrate via bumps.

18. A surface-emitting laser array comprising a plurality of surface-emitting lasers, each including a light-emitting portion comprising a first structure and a second structure having a mesa portion provided on the first structure, wherein the first structure and / or the second structure have an active layer having a light-emitting region, and the first structure has an oxidation structure that imparts anisotropic stress to the active layer.

19. The surface-emitting laser array according to claim 18, wherein the first structure of the plurality of surface-emitting lasers has a longitudinal shape in plan view.

20. The surface-emitting laser array according to claim 19, wherein the plurality of surface-emitting lasers are arranged such that the longitudinal directions of two adjacent surface-emitting lasers are parallel or perpendicular to each other.

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