Surface light-emitting element

Abstract

The present invention provides a surface light-emitting element that makes it possible to enhance robustness of reflectance distribution in an in-plane direction of a reflection structure against deviation from a design target value.　A surface light-emitting element according to the present invention comprises a layered structure including a light-emitting layer and a reflection structure that are layered onto each other. The layered structure has an emission surface on the side opposite from the reflection-structure side of the light-emitting layer. The reflection structure has a reflectance distribution in the in-plane direction. The surface light-emitting element according to the present invention can provide a surface light-emitting element that makes it possible to enhance robustness of the reflectance distribution in the in-plane direction of the reflection structure against deviation from a design target value.

Description

Surface-emitting element

[0001] The technology according to the present disclosure (hereinafter also referred to as "the technology") relates to a surface light emitting device.

[0002] 2. Description of the Related Art Conventionally, there has been known a surface-emitting device capable of obtaining a surface-emitting output, such as a surface-emitting laser, in which a light-emitting layer and a reflecting structure are stacked (see, for example, Patent Documents 1 and 2).

[0003] Conventional surface light emitting devices (for example, surface light emitting devices described in Patent Documents 1 and 2) have a reflecting structure on the light emitting surface side that has a reflectance distribution in the in-plane direction.

[0004] JP 2008-283028 A JP 2023-24359 A

[0005] However, conventional surface light emitting devices have room for improvement in terms of increasing robustness against deviations from the design target value of the reflectance distribution in the in-plane direction of the reflective structure.

[0006] Therefore, a main object of the present technology is to provide a surface light emitting device that can increase robustness against deviations from design target values ​​of the reflectance distribution in the in-plane direction of the reflective structure.

[0007] The present technology provides a surface-emitting device comprising a stacked structure including a light-emitting layer and a reflection structure stacked on top of each other, the stacked structure having an emission surface on the side of the light-emitting layer opposite the reflection structure, and the reflection structure having a reflectivity distribution in an in-plane direction. The reflection structure may have first and second portions having different positions and reflectivities in the in-plane direction. The first portion may correspond to a light-emitting region of the light-emitting layer. The second portion may surround the first portion. The reflectivity of the first portion may be lower than the reflectivity of the second portion. The reflectivity of the first portion may be higher than the reflectivity of the second portion. The reflection structure may include a multilayer film reflector having a plurality of refractive index layers stacked thereon, the multilayer film reflector being included in at least one of the first and second portions. The multilayer film reflector may be included in the first or second portion. The multilayer film reflector may be included in the first and second portions. The reflectivity of the multilayer film reflector in the first portion may be different from the reflectivity of the multilayer film reflector in the second portion. The number of refractive index layers of the multilayer film reflector in the first portion may be different from the number of refractive index layers of the multilayer film reflector in the second portion. The multilayer film reflector may be a dielectric multilayer film reflector. The reflection structure may have a metal reflector included in at least one of the first and second portions. The metal reflector may be included in the first portion or the second portion. The metal reflector may be included in the first portion and the second portion. The reflectance of the metal reflector in the first portion may be different from the reflectance of the metal reflector in the second portion. The metal reflector may also serve as an electrode and / or wiring. The reflection structure may have a multilayer film reflector having a plurality of stacked refractive index layers, the multilayer film reflector being included in at least one of the first and second portions, and a metal reflector included in at least one of the first and second portions. The surface light emitting device may further include a reflector arranged on the side of the light emitting layer opposite the reflection structure, and the lower of the reflectances of the first and second portions may be lower than the reflector.The surface-emitting device may further include a reflector arranged on the opposite side of the light-emitting layer from the reflective structure side, and the reflector may have the lowest reflectance among the reflectances of the first and second portions and the reflectance of the reflector.

[0008] 1 is a cross-sectional view of a surface light emitting device according to Example 1 of an embodiment of the present technology; FIG. 2 is a plan view of a surface light emitting device according to Example 1 of an embodiment of the present technology; FIG. 3 is a partially enlarged view of FIG. 1; FIG. 4 is a diagram illustrating a refractive index profile of a reflection structure of the surface light emitting device of FIG. 1; FIG. 5 is a diagram (part 1) illustrating a relationship between a radial position of a first portion in the reflection structure of the surface light emitting device of FIG. 1 and an effective mirror loss for each mode; FIG. 6 is a diagram (part 2) illustrating a relationship between a radial position of a first portion in the reflection structure of the surface light emitting device of FIG. 1 and an effective mirror loss for each mode; FIG. 7 is a flowchart (first half) for explaining an example of a manufacturing method of the surface light emitting device of FIG. 1; FIG. 8 is a flowchart (second half) for explaining an example of a manufacturing method of the surface light emitting device of FIG. 1; FIG. 9A and FIG. 9B are half-side cross-sectional views of each process of an example of a manufacturing method of the surface light emitting device of FIG. 1; FIG. 11A and FIG. 11B are half-side cross-sectional views of each process of an example of a manufacturing method of the surface light emitting device of FIG. 1; FIG. 12A and FIG. 12B are half-side cross-sectional views of each process of an example of a manufacturing method of the surface light emitting device of FIG. 1; 13A and 13B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 1 . FIGS. 14A and 14B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 1 . FIGS. 15A and 15B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 1 . FIGS. 16A and 16 ...B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 1 . FIGS. 16B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 1 . FIGS. 16B are partially enlarged cross-sectional views of a surface light emitting device according to Example 2 of an embodiment of the present technology. FIGS. 16A and 16B are a flowchart (first half) for describing an example of a method for manufacturing the surface light emitting device of FIG. 18 . FIGS. 16B are a flowchart (second half) for describing an example of a method for manufacturing the surface light emitting device of FIG. 18 . FIGS. 21A and 21B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 18 . FIGS. 22A and 22B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 18 . FIGS. 23A and 23B are half-side cross-sectional views of each step Figures 24A and 24B are half-side cross-sectional views of each step in an example of a method for manufacturing the surface light emitting device of Figure 18. Figures 25A and 25B are half-side cross-sectional views of each step in an example of a method for manufacturing the surface light emitting device of Figure 18.26A and 26B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 18 . FIGS. 27A and 27B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 18 . FIGS. 27A and 27B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 18 . FIGS. 27A and 27B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 18 . FIGS. 27A and 27B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 18 . FIGS. 27A and 27B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 18 . FIGS. 27A and 27B are half-side cross-sectional views of each step of an example of a method for manufacturing the surface light emitting device of FIG. 29 . 36A and 36B are half-side cross-sectional views of each step of an example of a manufacturing method of the surface light emitting device of FIG. 29 . FIGS. 37A and 37B are half-side cross-sectional views of each step of an example of a manufacturing method of the surface light emitting device of FIG. 29 . FIG. 37B is a partially enlarged cross-sectional view of a surface light emitting device according to Example 4 of an embodiment of the present technology. FIG. 37C is a partially enlarged cross-sectional view (part 1) of a surface light emitting device according to Example 5 of an embodiment of the present technology. FIG. 37D is a partially enlarged cross-sectional view (part 2) of a surface light emitting device according to Example 5 of an embodiment of the present technology. FIG. 37E is a plan view of a surface light emitting device according to Example 5 of an embodiment of the present technology. FIG. 37F is a partially enlarged cross-sectional view of a surface light emitting device according to Example 6 of an embodiment of the present technology. FIG. 37G is a cross-sectional view of a surface light emitting device according to Example 7 of an embodiment of the present technology. FIG. 37H is a cross-sectional view of a surface light emitting device according to Example 8 of an embodiment of the present technology. FIG. 37I is a cross-sectional view of a surface light emitting device according to Example 9 of an embodiment of the present technology. FIG. 37I is a cross-sectional view of a surface light emitting device according to Example 10 of an embodiment of the present technology. FIG. 37J is a cross-sectional view of a surface light emitting device according to Example 11 of an embodiment of the present technology. FIG. 37I is a cross-sectional view of a surface light emitting device according to Example 12 of an embodiment of the present technology. FIG. 37I is a cross-sectional view of a surface light emitting device according to Example 13 of an embodiment of the present technology. FIG. 37I is a cross-sectional view of 15A and 15B are cross-sectional views of a surface light emitting device according to Example 15 of an embodiment of the present technology;FIG. 10 is a cross-sectional view of a surface light emitting device according to Example 17 of an embodiment of the present technology. FIG. 11 is a plan view of a surface light emitting device according to Example 18 of an embodiment of the present technology. FIG. 12 is a plan view of a surface light emitting device according to Example 19 of an embodiment of the present technology. FIG. 13 is a cross-sectional view of a surface light emitting device according to Example 20 of an embodiment of the present technology. FIG. 14 is a cross-sectional view of a surface light emitting device according to Example 21 of an embodiment of the present technology. FIG. 15 is a diagram showing a refractive index profile of a reflection structure of a surface light emitting device according to a modified example of an embodiment of the present technology. FIG. 16 is a diagram showing an example of application of a surface light emitting device according to Example 1 of an embodiment of the present technology to a distance measurement device. FIG. 17 is a block diagram showing an example of a schematic configuration of a vehicle control system. FIG. 18 is an explanatory diagram showing an example of an installation position of a distance measurement device.

[0009] Preferred embodiments of the present technology will be described in detail below with reference to the accompanying drawings. Note that in this specification and the drawings, components having substantially the same functional configurations are denoted by the same reference numerals, and redundant description will be omitted. The embodiments described below illustrate typical embodiments of the present technology, and the scope of the present technology should not be interpreted narrowly. Even when it is described in this specification that a surface light emitting device according to the present technology has multiple effects, it is sufficient that the surface light emitting device according to the present technology has at least one effect. The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0010] The description will be made in the following order: 0. Introduction 1. Surface-light-emitting device according to Example 1 of one embodiment of the present technology 2. Surface-light-emitting device according to Example 2 of one embodiment of the present technology 3. Surface-light-emitting device according to Example 3 of one embodiment of the present technology 4. Surface-light-emitting device according to Example 4 of one embodiment of the present technology 5. Surface-light-emitting device according to Example 5 of one embodiment of the present technology 6. Surface-light-emitting device according to Example 6 of one embodiment of the present technology 7. Surface-light-emitting device according to Example 7 of one embodiment of the present technology 8. Surface-light-emitting device according to Example 8 of one embodiment of the present technology 9. Surface-light-emitting device according to Example 9 of one embodiment of the present technology 10. Surface-light-emitting device according to Example 10 of one embodiment of the present technology 11. Surface-light-emitting device according to Example 11 of one embodiment of the present technology 12. Surface-light-emitting device according to Example 12 of one embodiment of the present technology 13. Surface-light-emitting device according to Example 13 of one embodiment of the present technology 14. Surface-light-emitting device according to Example 14 of one embodiment of the present technology 15. Surface-light-emitting device according to Example 15 of one embodiment of the present technology 16. Surface-light-emitting device according to Example 16 of one embodiment of the present technology 17. Surface light emitting device according to Example 17 of an embodiment of the present technology 18. Surface light emitting device according to Example 18 of an embodiment of the present technology 19. Surface light emitting device according to Example 19 of an embodiment of the present technology 20. Surface light emitting device according to Example 20 of an embodiment of the present technology 21. Surface light emitting device according to Example 21 of an embodiment of the present technology 22. Modification of the present technology 23. Application example to electronic device 24. Example of application of surface light emitting device to distance measurement device 25. Example of mounting distance measurement device on a moving body

[0011] <0. Introduction>

[0012] (Concept of the present technology) In conventional surface light emitting devices (for example, the surface light emitting devices described in Patent Documents 1 and 2), the reflective structure having an in-plane reflectance distribution is located on the light output surface side, and therefore light must be transmitted, which limits the degree of freedom in material and structural selection. For this reason, the reflective structure of conventional surface light emitting devices has low robustness against deviations of the in-plane reflectance distribution from the design target value.

[0013] Therefore, after extensive research, the inventors have succeeded in developing a surface light emitting device according to the present technology that is capable of increasing robustness against deviations from the design target value of the reflectance distribution of the reflective structure.

[0014] The surface-emitting device according to the present technology has an emission surface on the side opposite to the reflective structure side of the light-emitting layer, thereby increasing the degree of freedom in the selection of materials and structures for the reflective structure, and ultimately making it possible to increase robustness against deviations from the design target value of the reflectivity distribution in the in-plane direction of the reflective structure.

[0015] Furthermore, the surface light emitting device according to the present technology can control the transverse mode by setting the reflectance distribution in the in-plane direction of the reflective structure, and thus can control the radiation angle (NA: Numerical Aperture).

[0016] Incidentally, in recent years, sensing technology has become important, as exemplified by distance measurement applications using time of flight and structured light, and facial recognition. The basic components for realizing these sensing applications are a light source and a light-receiving element. The optical characteristics (wavelength, pulse emission width, radiation angle, spot size) required of the light source vary depending on the purpose of the application. However, when a surface-emitting element array chip in which surface-emitting elements such as surface-emitting lasers and light-emitting diodes are arranged in an array is generally used as a light source, the multiple light-emitting elements included in a single chip have the same radiation angle, making it difficult to control the radiation angle over a wide range for each light-emitting element.

[0017] The surface-emitting device according to the present technology can control the ratio of fundamental and higher-order transverse modes by setting the reflectivity distribution in the in-plane direction of the reflective structure, and thus can arbitrarily control the radiation angle of the emitted light.

[0018] Hereinafter, several examples of an embodiment of a surface light emitting device according to the present technology will be described in detail with reference to the drawings. In the following, in cross-sectional views such as Fig. 1, the upper side will be referred to as "upper" and the lower side will be referred to as "lower". The term "same" used in this specification includes not only completely same but also substantially same (when there is a slight difference within the range of the same effect).

[0019] 1. Surface light emitting device according to Example 1 of an embodiment of the present technology> Fig. 1 is a cross-sectional view of a surface light emitting device 10 according to Example 1 of an embodiment of the present technology. Fig. 2 is a plan view (top view) of the surface light emitting device 10 according to Example 1 of an embodiment of the present technology. Fig. 1 is a cross-sectional view taken along line 1-1 in Fig. 2.

[0020] <Configuration of Surface-Emitting Element> (Overall Configuration) A surface-emitting element 10 according to Example 1 of an embodiment of the present technology is a vertical cavity surface-emitting laser (VCSEL) as shown in Fig. 1 and Fig. 2 . The surface-emitting element 10 is, for example, a back-emitting VCSEL. The oscillation wavelength λ of the surface-emitting element 10 is, for example, 400 nm to 1550 nm (for example, 940 nm in the case of a GaAs-based element).

[0021] The surface light emitting element 10 is driven by, for example, a driver (drive circuit), which includes, for example, a power supply and a transistor that turns on and off the power supply to the surface light emitting element 10 .

[0022] The surface light emitting device 10 includes, for example, a laminated structure LS including a light emitting layer 103 and a reflective structure 108 stacked on top of each other. The laminated structure LS has an emission surface ES on the side of the light emitting layer 103 opposite to the reflective structure 108 side.

[0023] As an example, the stacked structure LS further includes a first semiconductor multilayer film reflector 102 (reflector) arranged on the side opposite (below) the reflective structure 108 side of the light emitting layer 103, and a second semiconductor multilayer film reflector 104 (reflector) arranged between the light emitting layer 103 and the reflective structure 108. The first and second semiconductor multilayer film reflectors 102 and 104 have different conductivity types.

[0024] The stacked structure LS further includes, for example, a substrate 101 arranged on the side of the first semiconductor multilayer film reflector 102 opposite to the light emitting layer 103 side.

[0025] As an example, the stacked structure LS further includes an oxide constriction layer 105 (current constriction layer) disposed inside the second semiconductor multilayer film reflector 104. The oxide constriction layer 105 defines a light emitting region LA of the light emitting layer 103. The light emitting region LA corresponds to the non-oxidized region 105a of the oxide constriction layer 105, and is a region in the light emitting layer 103 into which a current is injected (current injection region) and which emits light.

[0026] The stacked structure LS further includes, for example, a contact layer 106 arranged on the opposite side (upper side) of the second semiconductor multilayer film reflector 104 from the light emitting layer 103 side.

[0027] As described above, in the surface-emitting device 10, as an example, a first semiconductor multilayer reflector 102, a light-emitting layer 103, a second semiconductor multilayer reflector 104 having an oxide constriction layer 105 disposed therein, and a contact layer 106 are stacked on a substrate 101 in this order from the substrate 101 side (bottom side).

[0028] The surface light emitting device 10 has a double hetero structure in which the light emitting layer 103 is sandwiched in the plane-perpendicular direction (up and down direction) between first and second semiconductor multilayer film reflectors 102 and 104 of different conductivity types, and holes and electrons can undergo radiative recombination (radiative recombination) in the light emitting layer 103. Note that the surface light emitting device 10 may have a configuration in which a double hetero structure in which the light emitting layer 103 is sandwiched in the plane-perpendicular direction between first and second clad layers (semiconductor layers) of different conductivity types is sandwiched in the plane-perpendicular direction between the first and second semiconductor multilayer film reflectors 102 and 104.

[0029] In the surface-emitting element 10, a resonator is formed including a light-emitting layer 103 and first and second semiconductor multilayer film reflectors 102 and 104 that sandwich the light-emitting layer 103 in the direction perpendicular to the surface. The surface-emitting element 10 emits laser light from an emission surface ES, which is the surface of the laminate structure LS facing the substrate 101 (the back surface of the substrate 101).

[0030] The first and second semiconductor multilayer film reflectors 102, 104 have high reflectivities, enabling vertical light confinement within the resonator. Furthermore, the oxidized confinement layer 105 has a horizontal refractive index distribution within the resonator, enabling lateral light confinement to the central high-refractive-index portion (non-oxidized region 105a). In other words, the surface-emitting device 10 can achieve high three-dimensional light confinement near the light-emitting layer 103 through vertical and horizontal light confinement within the resonator.

[0031] As an example, a recess DP defining at least a mesa structure MS is provided on the surface (top surface) of the stacked structure LS opposite the substrate 101. The recess DP exposes at least the side surface of the oxide constriction layer 105. Here, the recess DP is a notch or a groove. As an example, the mesa structure MS includes a first semiconductor multilayer reflector 102, a light-emitting layer 103, a second semiconductor multilayer reflector 104, an oxide constriction layer 105, and a contact layer 106. The mesa structure MS is also referred to as a "light-emitting mesa." Here, the shape of the mesa structure MS in a plan view is circular (see FIG. 2 ), but it may be other shapes such as elliptical or polygonal. As an example, the diameter of the mesa structure MS is several tens of μm (e.g., 10 μm to 30 μm).

[0032] As an example, an anode electrode 107 (p-side electrode) and a reflective structure 108 are provided on the top of the mesa structure MS (more specifically, on the contact layer 106). The anode electrode 107 is provided in a circumferential shape (for example, a ring shape (more specifically, a split ring shape), in a broad sense, with or without an interrupted portion) so as to surround the light emitting region LA in a plan view.

[0033] As an example, at least the side surfaces of the mesa structure MS and a region around the mesa structure MS on the upper surface (front surface) of the substrate 101 are covered with a first insulating film 112. The first insulating film 112 is made of a dielectric material such as SiN, SiO, or SiON.

[0034] As an example, on the region around the mesa structure MS on the upper surface (front surface) of the substrate 101, a cathode electrode 109 (n-side electrode) is provided so as to surround the mesa structure MS and so as to overlap the first insulating film 112 at its inner peripheral end, and further, a cathode wiring 111 is provided so as to cover the cathode electrode 109 from above and to surround the mesa structure MS via the first insulating film 112. The cathode wiring 111 is electrically connected to the cathode side of the driver.

[0035] That is, the surface light emitting device 10 has an intra-cavity structure in which the anode electrode 107 and the cathode electrode 109 are arranged on the same surface side of the substrate 101 .

[0036] As an example, the first insulating film 112 provided on at least the side surface of the mesa structure MS and the cathode wiring 111 are covered with the second insulating film 113. The second insulating film 113 is made of a dielectric material such as SiN, SiO, or SiON.

[0037] As an example, the surface light emitting device 10 is mounted on a mounting substrate (for example, a drive substrate having a driver, a wiring substrate connected to the driver, etc.) in a junction-down (flip-chip) manner.

[0038] (Substrate) The substrate 101 is, for example, a semi-insulating substrate (for example, a semi-insulating GaAs substrate).

[0039] (First Semiconductor Multilayer Reflector) The first semiconductor multilayer reflector 102 (semiconductor DBR), for example, is a semiconductor multilayer reflector doped with n-type impurities, and has low light absorption, high reflectivity, and electrical conductivity. Multilayer reflectors are also called distributed Bragg reflectors (DBRs). The first semiconductor multilayer reflector 102 has a structure in which high-refractive index layers and low-refractive index layers with different refractive indices are alternately stacked with an optical thickness equal to one-quarter of the emission wavelength of each light-emitting layer. The low-refractive index layers are made of a compound semiconductor containing Al (e.g., AlGaAs, AlAs, etc.). The high-refractive index layers are made of a compound semiconductor (e.g., AlGaAs, GaAs, etc.). The low-refractive index layers are high-Al composition layers with a higher Al composition than the high-refractive index layers. It is preferable that the refractive index difference (Al composition difference) between the high-refractive index layers and the low-refractive index layers be as large as possible. This is because high reflectivity can be obtained with a small number of pairs. The Al composition of the low refractive index layer is preferably 0.8 or more, more preferably 0.85 or more, even more preferably 0.9 or more, and even more preferably 0.95 or more. The Al composition of the high refractive index layer is preferably 0.2 or less, more preferably 0.15 or less, even more preferably 0.1 or less, and even more preferably 0.05 or less. Examples of n-type impurities (n-type dopants) in the first semiconductor multilayer film reflector 102 include Si, Se, and Ge. The reflectivity of the first semiconductor multilayer film reflector 102 is set to, for example, 98.7%.

[0040] (Light Emitting Layer) The light emitting layer 103 is made of, for example, a compound semiconductor having a band gap energy smaller than that of each refractive index layer of the first and second semiconductor multilayer film reflectors 102 and 104. The light emitting layer 103 is made of, for example, a GaAs-based compound semiconductor (e.g., GaAs, AlGaAs, GaInAs, GaInAsN, etc.). The light emitting layer 103 may have any of a quantum well structure, a multiple quantum well structure, a quantum wire structure, and a quantum dot structure. The emission wavelength of the light emitting layer 103 is set to, for example, about 400 to 1550 nm. The light emitting layer 103 is preferably disposed at or near the antinode of a standing wave generated in the resonator. The light emitting layer is also called an "active layer."

[0041] (Second Semiconductor Multilayer Reflector) The second semiconductor multilayer reflector 104 (semiconductor DBR), for example, is a semiconductor multilayer reflector doped with p-type impurities, and has low light absorption, high reflectivity, and electrical conductivity. Multilayer reflectors are also called distributed Bragg reflectors (DBRs). The second semiconductor multilayer reflector 104 has a structure in which high-refractive index layers and low-refractive index layers with different refractive indices are alternately stacked with an optical thickness equal to one-quarter of the emission wavelength of each light-emitting layer. The low-refractive index layers are made of a compound semiconductor containing Al (e.g., AlGaAs, AlAs, etc.). The high-refractive index layers are made of a compound semiconductor (e.g., AlGaAs, GaAs, etc.). The low-refractive index layers are high-Al composition layers with a higher Al composition than the high-refractive index layers. It is preferable that the refractive index difference (Al composition difference) between the high-refractive index layers and the low-refractive index layers is large. This is because high reflectivity can be obtained with a small number of pairs. The Al composition of the low refractive index layer is preferably 0.8 or more, more preferably 0.85 or more, even more preferably 0.9 or more, and even more preferably 0.95 or more. The Al composition of the high refractive index layer is preferably 0.2 or less, more preferably 0.15 or less, even more preferably 0.1 or less, and even more preferably 0.05 or less. Examples of p-type impurities (p-type dopants) in the second semiconductor multilayer reflector 104 include Zn, Mg, Be, and C. Here, the reflectivity of the second semiconductor multilayer reflector 104 is set to the same as that of the first semiconductor multilayer reflector 102 (e.g., 98.7%).

[0042] (Oxidized Constriction Layer) As an example, the oxidized constriction layer 105 has a non-oxidized region 105a and an oxidized region 105b surrounding the non-oxidized region 105a. The outer peripheral shape of the non-oxidized region 105a is determined by the inner peripheral shape of the oxidized region 105b. The inner peripheral shape of the oxidized region 105b is determined by the outer peripheral shape of the mesa structure MS. The diameter (average diameter) of the non-oxidized region 105a is determined by the inner diameter (average inner diameter) of the oxidized region 105b. The oxidized constriction layer 105 is preferably disposed at or near the node of a standing wave generated in the resonator. In the oxidized constriction layer, the non-oxidized region is also referred to as an OA (Oxide Aperture) (hereinafter the same). In the oxidized constriction layer, the diameter of the non-oxidized region, that is, the oxide constriction diameter, is also referred to as the OA diameter (hereinafter the same).

[0043] The non-oxidized region 105a functions as a current / light passing region. For example, the non-oxidized region 105a includes an Al-containing compound semiconductor (e.g., AlGaAs, AlAs, etc.). The non-oxidized region 105a preferably has an Al composition of 0.8 or more, more preferably 0.85 or more, even more preferably 0.9 or more, and even more preferably 0.95 or more.

[0044] The oxidized region 105b is, for example, a circular (for example, ring-shaped) region in plan view that surrounds the non-oxidized region 105a. The oxidized region 105b has a higher resistance and a lower refractive index than the non-oxidized region 105a, and functions as a current / light confinement region. For example, the oxidized region 105b is made of an oxide containing Al (for example, Al x O y etc.)

[0045] (Anode Electrode) The anode electrode 107 may have a single-layer structure or a laminated structure. The anode electrode 107 is made 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. When the anode electrode 107 has a laminated structure, it is made 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, or the like.

[0046] (Cathode Electrode) The cathode electrode 109 may have a single-layer structure or a laminated structure. The cathode electrode 109 is made 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. When the cathode electrode 109 has a laminated structure, it is made 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, or the like.

[0047] (Cathode Wiring) The cathode wiring 111 is made of plating containing, for example, Au, Ag, Cu, Al, Zn, or the like.

[0048] (Reflecting Structure) Fig. 3 is a partially enlarged view of Fig. 1, more specifically, a partially enlarged view of the area surrounded by the dashed line in Fig. 1. The left edge of Fig. 3 corresponds to the center of the oxidized region 105b in the in-plane direction.

[0049] The reflective structure 108 has a reflectance distribution in the in-plane direction. More specifically, as shown in FIGS. 1 and 3, the reflective structure 108 has first and second portions 108-1 and 108-2 that differ in in-plane position and reflectance. The first portion 108-1 corresponds to the light-emitting region LA of the light-emitting layer 103. That is, the first portion 108-1 also corresponds to the non-oxidized region 105a of the oxidized constriction layer 105. The second portion 108-2 surrounds the first portion 108-1. Here, the first portion 108-1 has a circular shape in plan view, and the second portion has a circular shape in plan view (e.g., annular) (see FIG. 2), but these shapes can be changed as appropriate. The planar shape of the first portion 108-1 may be a polygon, such as an ellipse, square, or rectangle. The shape of the second portion 108-2 in a plan view may be a shape corresponding to the shape of the first portion 108-1 in a plan view (for example, an elliptical ring, a square frame, a rectangular frame, or other polygonal frame shape).

[0050] For example, the reflectance of the first portion 108-1 is higher than the reflectance of the second portion 108-2. Furthermore, for example, the reflectance of the first portion 108-1 is higher than the reflectance (e.g., 98.7%) of the first and second semiconductor multilayer film reflectors 102, 104, and the reflectance of the second portion 108-2 is lower than the reflectance of the first and second semiconductor multilayer film reflectors 102, 104. Specifically, the reflectance of the first portion 108-1 is, for example, 99.9%. The reflectance of the second portion 108-2 is, for example, 93.9%. Of the reflectances of the first and second portions 108-1, 108-2 and the reflectances of the first and second semiconductor multilayer film reflectors 102, 104, at least one of the reflectances of the first and second semiconductor multilayer film reflectors 102, 104 may have the lowest reflectance.

[0051] As an example, the reflecting structure 108 has a multilayer reflector 108a, which is a multilayer reflector formed by stacking a plurality of refractive index layers and is included in the first and second portions 108-1 and 108-2. In other words, the multilayer reflector 108a straddles the first and second portions 108-1 and 108-2. As an example, the multilayer reflector 108a is provided on the contact layer 106 so as to expose the anode electrode 107.

[0052] As an example, the reflecting structure 108 has a metal reflecting mirror 108b included in the first and second portions 108-1 and 108-2. That is, the metal reflecting mirror 108b straddles the first and second portions 108-1 and 108-2. The metal reflecting mirror 108b is provided on the multilayer film reflecting mirror 108a so as to be in contact with the anode electrode 107. In this example, the reflectance of the metal reflecting mirror 108b in the first portion 108-1 is the same as the reflectance of the metal reflecting mirror 108b in the second portion 108-2.

[0053] As described above, the reflecting structure 108 is a hybrid mirror including the multilayer reflecting mirror 108 a and the metal reflecting mirror 108 b. Advantages of using such a hybrid mirror in the reflecting structure 108 include the fact that the number of refractive index layers of the multilayer reflecting mirror required to obtain the required reflectance can be reduced compared to when only a multilayer reflecting mirror is used, and that the metal reflecting mirror can also be used as an electrode or wiring.

[0054] The metal reflector 108b has a reflector portion corresponding to the first and second portions 108-1 and 108-2 of the multilayer film reflector 108a, and a contact portion that is continuous with the reflector portion and contacts the anode electrode 107. In other words, the metal reflector 108b also functions as an anode wiring for electrode extraction from the anode electrode 107. The metal reflector 108b as an anode wiring is electrically connected to the anode side of the driver. The reflector portion can also function as a bump bonding portion when bonding the substrate junction-down. A third insulating film 114, a first insulating film 112, and a second insulating film 113 are laminated in this order on the outer peripheral edge of the contact portion as protective films. The third insulating film 114 is made of a dielectric material such as SiN, SiO, or SiON.

[0055] As an example, the metal reflecting mirror 108b has a seed layer 108b1 provided on the multilayer film reflecting mirror 108a and a plating layer 108b2 provided on the seed layer 108b1. The plating layer 108b2 is made of plating such as Au, Ag, Cu, Al, or Zn.

[0056] As an example, the reflectance of the multilayer reflector 108a in the first portion 108-1 is higher than the reflectance of the multilayer reflector 108a in the second portion 108-2. More specifically, the number of refractive index layers in the multilayer reflector 108a in the first portion 108-1 (hereinafter also referred to as the "central portion of the multilayer reflector") is greater than the number of refractive index layers in the multilayer reflector 108a in the second portion 108-2 (hereinafter referred to as the "peripheral portion of the multilayer reflector"). It is preferable that the difference between the number of refractive index layers in the central portion of the multilayer reflector and the number of refractive index layers in the peripheral portion of the multilayer reflector is an odd number. Here, the central portion of the multilayer reflector has a five-layer structure with, for example, five refractive index layers stacked, and the peripheral portion of the multilayer reflector has a four-layer structure with, for example, four refractive index layers stacked.

[0057] The multilayer film reflector 108a is, for example, a dielectric multilayer film reflector. In the dielectric multilayer film reflector, multiple refractive index layers with different refractive indices are periodically (e.g., alternately) stacked. Examples of materials for the dielectric multilayer film reflector include Si, SiO, TaO, NbO, SiN, MgF, HfO, AlO, and TiO. Here, Si / SiO is used as the high refractive index material / low refractive index material, but TaO / SiO, SiN / SiO, NbO / SiO, and the like may also be used. The multilayer film reflector 108a may also be a semiconductor multilayer film reflector.

[0058] As described above, the reflecting structure 108 constitutes a dielectric multilayer metal mirror (DMM) including the dielectric multilayer reflecting mirror as the multilayer reflecting mirror 108a and the metal reflecting mirror 108b.

[0059] Advantages of using a DMM for the reflection structure 108 include the fact that high reflectivity can be obtained with a small number of dielectric multilayer film reflectors, and that it is easy to achieve a large in-plane reflectivity difference (reflectivity contrast) even if the difference in the number of dielectric layers is small; for example, the number of dielectric film layers required to obtain the required reflectivity can be reduced compared to when only a dielectric multilayer film reflector is used, and that the NA can be controlled independently without compromising the slope efficiency and the electrical-to-optical conversion efficiency.

[0060] One advantage of using a dielectric multilayer reflector for the multilayer reflector 108a is that the dielectric film is highly robust against variations in film thickness and line width. This is supported by the fact that the dielectric film showed only minor fluctuations in its characteristics as a sensing light source when the film thickness and line width varied by ±30% or less.

[0061] Furthermore, verification of the positional tolerance (overlay error in lithography) of the high reflectivity portion of a surface-emitting VCSEL having a surface relief structure as described in Patent Document 1 has yielded results showing that an overlay error of approximately ±1.2 μm is acceptable. It is believed that the present technology also has a similar overlay tolerance.

[0062] In the reflecting structure 108, the robustness of the dielectric film of the multilayer reflecting mirror 108a against film thickness / linewidth variations leads to increased robustness against deviations of the reflectance distribution of the reflecting structure 108 from the design target value.

[0063] In the reflective structure 108, there is a step at the boundary between the first and second portions 108-1 and 108-2 due to the difference in the number of refractive index layers between the first and second portions 108-1 and 108-2, and there is unevenness at the boundary between the second portion 108-2 and the anode electrode 107 due to the reflective structure 108 overlapping the inner peripheral end of the anode electrode 107. Such a step or unevenness exerts an anchor effect and contributes to improving the bonding strength, for example, when the reflective structure 108 and an anode terminal of a mounting substrate are bonded via a bump.

[0064] The central portion of the multilayer reflector has, for example, a five-layer dielectric structure in which first to fifth dielectric layers 108a1 to 108a5 are stacked in this order from the contact layer 106 side (bottom side).

[0065] The peripheral portion of the multilayer reflector has, as an example, a four-layer dielectric structure in which second to fifth dielectric layers 108a1 to 108a4 are stacked in this order from the contact layer 106 side (bottom side).

[0066] For example, the first, third, and fifth dielectric layers 108a1, 108a3, and 108a5 are all low-refractive-index layers (e.g., SiO layers). For example, the second and fourth dielectric layers 108a2 and 108a4 are all high-refractive-index layers (e.g., Si layers). Here, the thickness (e.g., 162 nm) of the low-refractive-index layers (e.g., SiO layers) is set to be thicker than the thickness (e.g., 67 nm) of the high-refractive-index layers (e.g., Si layers).

[0067] Fig. 4 is a diagram showing the refractive index profile of the reflecting structure 108 of the surface light emitting device 10 of Fig. 1. Numbers 1 to 5 in Fig. 4 correspond to n (1 to 5) of the n-th dielectric layer, respectively.

[0068] As shown in FIG. 4, the five-layer dielectric structure as the central portion of the multilayer reflector has a refractive index change from the contact layer 106 side (bottom side) in which low refractive indexes and high refractive indexes are alternately repeated such that odd-numbered layers (first, third, and fifth) have low refractive indexes and even-numbered layers (second and fourth) have high refractive indexes.

[0069] As shown in FIG. 4, the four-layer dielectric structure as the central portion of the multilayer reflector has a refractive index change from the contact layer 106 side (bottom side) in which low and high refractive indices are alternately repeated, with odd-numbered layers (first and third) having high refractive indices and even-numbered layers (second and fourth) having low refractive indices.

[0070] Here, the oxidized constriction diameter (OA diameter) of the oxidized constriction layer 105 is preferably in the range of, for example, 4 to 15 μm, and more preferably in the range of, for example, 6 to 10 μm.

[0071] The radius of the first portion 108-1, as a relative value (a value normalized by the OA radius, the same applies below) based on the OA radius (half the OA radius), is preferably in the range of 0.2 to 2, more preferably in the range of 0.5 to 2, and still more preferably in the range of 0.8 to 2. The lower limit of the radius of the first portion 108-1, as a relative value based on the OA radius, preferably exceeds 1.

[0072] The positional deviation between the center of the non-oxidized region 105a of the oxidized constriction layer 105 and the center of the first portion 108-1 is preferably 3 μm or less, more preferably 2 μm or less, and even more preferably 1 μm or less.

[0073] Fig. 5 is a diagram (part 1) showing the relationship between the radial position of the first portion 108-1 in the reflecting structure 108 of the surface-emitting device 10 in Fig. 1 and the effective mirror loss for each oscillation mode. Fig. 6 is a diagram (part 2) showing the relationship between the radial position of the first portion 108-1 in the reflecting structure 108 of the surface-emitting device 10 in Fig. 1 and the effective mirror loss for each oscillation mode. In Figs. 5 and 6, the horizontal axis (radial position of the first portion, normalized by the OA radius) has its origin at the left end of the enlarged partial view of Fig. 3 (the center in the in-plane direction of the oxidized region 105b).

[0074] As can be seen from Figures 5 and 6, the effective mirror loss [1 / cm] for each oscillation mode changes depending on the radial position of the first portion 108-1, normalized by the OA radius. Generally, the smaller the mirror loss, the smaller the threshold current for laser oscillation. In Figures 5 and 6, within the range of 0.4 to 1.0 on the horizontal axis, oscillation occurs predominantly in the fundamental mode (LP01), which has a smaller mirror loss, while oscillation in higher-order modes (LP02, LP03, LP04, LP21, LP22, LP23, LP24), which have a larger mirror loss, is suppressed. This allows the radiation angle (NA) to be smaller than that of conventional surface-emitting devices.

[0075] Furthermore, as a result of evaluating the light-emitting performance of a prototype of the surface-emitting device 10, data was obtained showing that the actual measured value of the radiation angle changes linearly (straight line) in accordance with the change in the radial position of the first portion 108-1 normalized by the OA radius. This makes it possible to easily obtain the diameter of the first portion 108-1 for obtaining a desired radiation angle from the correspondence relationship between the diameter of the first portion 108-1 and the radiation angle.

[0076] <Operation of Surface-Emitting Device> The operation of the surface-emitting device 10 will now be described with reference to FIG. 1 . When a power supply voltage of the driver is applied between the anode electrode 107 and the cathode electrode 109, a current flows from the anode side of the driver through the metal reflector 108b (which serves as an anode wiring) and the anode electrode 107 into the mesa structure MS. The current flowing into the mesa structure MS passes through the contact layer 106 and the upper part of the second semiconductor multilayer film reflector 104, in this order, is constricted by the oxide constriction layer 105, and is injected into the light-emitting layer 103 through the lower part of the second semiconductor multilayer film reflector 104. At this time, the light-emitting layer 103 emits light, and the light travels back and forth between the first and second semiconductor multilayer film reflectors 102 and 104, being constricted by the oxide constriction layer 105 and amplified by the light-emitting layer 103. When oscillation conditions are satisfied, the light is emitted as laser light from the back surface (emission surface ES) of the substrate 101. This laser light becomes a beam with a narrow radiation angle in which higher-order modes are suppressed and the fundamental mode oscillates predominantly due to the action of the reflecting structure 108. The current injected into the light-emitting layer 103 flows through the first semiconductor multilayer film reflecting mirror 102, the substrate 101, the cathode electrode 109, and the cathode wiring 111 in this order, and is then output to the cathode side of the driver.

[0077] <<Method of Manufacturing Surface Light-Emitting Device>> An example of a method of manufacturing the surface light-emitting device 10 will be described below with reference to the flowcharts in Figures 7 and 8 and half-side cross-sectional views of each process. The overall flow is as follows: First, a semiconductor manufacturing method using semiconductor manufacturing equipment is used to simultaneously produce a plurality of surface light-emitting devices 10 on a single wafer (hereinafter, also referred to as "substrate 101" for convenience) that is the base material of the substrate 101. Next, the series of multiple surface light-emitting devices 10 are separated from each other by dicing (e.g., stealth dicing) to obtain chip-shaped surface light-emitting devices 10.

[0078] In the first step S1, a stack is produced (see FIG. 9A ). Specifically, a first semiconductor multilayer reflector 102, a light-emitting layer 103, a second semiconductor multilayer reflector 104 having an oxidized layer 105S disposed therein, and a contact layer 106 are stacked in this order on a substrate 101 as a growth substrate by an epitaxial crystal growth method such as MOCVD (Metal Organic Chemical Vapor Deposition). The oxidized layer 105S is a compound semiconductor layer (e.g., an AlGaAs layer or an AlAs layer) that will be the material for the oxidized constriction layer 105. When producing the laminate, methyl-based organometallic gases such as trimethylaluminum (TMAl), trimethylgallium (TMGa), and trimethylindium (TMIn), and arsine (AsH) gas are used as raw materials for the compound semiconductor, disilane (SiH) is used as a raw material for the donor impurity, and carbon tetrabromide (CBr) is used as a raw material for the acceptor impurity.

[0079] In the next step S2, the anode electrode 107 is formed (see FIG. 9B ). Specifically, the anode electrode 107 is formed in a circumferential shape (e.g., a ring shape) in a planar view on the laminate (specifically, on the contact layer 106) by, for example, a lift-off method. At this time, deposition, sputtering, or the like is used to form a film of the electrode material.

[0080] In the next step S3, the first dielectric layer 108a1 is formed (see FIG. 10 ). Specifically, the first dielectric layer 108a1 is formed by, for example, vapor deposition, sputtering, or the like on the stack (specifically, the contact layer 106) on which the anode electrode 107 is formed.

[0081] In the next step S4, a portion of the first dielectric layer 108a1 is removed (see FIG. 11A). Specifically, a portion of the first dielectric layer 108a1 where the second portion 108-2 will be formed (a portion that is convoluted in plan view) is removed by photolithography and etching. As a result, a portion of the contact layer 106 (a portion that is convoluted in plan view) is exposed.

[0082] In the next step S5, the second to fifth dielectric layers 108a2 to 108a5 are formed (see FIG. 11B). Specifically, the second to fifth dielectric layers 108a2 to 108a5 are formed in this order by, for example, vapor deposition or sputtering on the first dielectric layer 108a1 and on the exposed portion of the contact layer 106. As a result, the multilayer film reflector 108a is formed.

[0083] In the next step S6, a first contact hole CH1 is formed (see FIG. 12A). Specifically, a portion of the multilayer film reflector 108a is removed by photolithography and etching to form a circular first contact hole CH1 that exposes the anode electrode 107.

[0084] In the next step S7, a metal reflecting mirror 108b is formed as an anode wiring (see FIG. 12B). Specifically, a seed layer is first formed on a portion of the multilayer film reflecting mirror 108a and on the anode electrode 107, for example, by vapor deposition or sputtering. Next, a plating layer is formed on the seed layer, for example, by plating. As a result, the metal reflecting mirror 108b is formed.

[0085] In the next step S8, the third insulating film 114 is formed (see FIG. 13A). Specifically, the third insulating film 114 is formed on the entire surface by, for example, vapor deposition, sputtering, or the like.

[0086] In the next step S9, the mesa M is formed (see FIG. 13B). Specifically, first, a resist pattern for forming the mesa M is formed by photolithography on the layered structure including the multilayer reflector 108a and the metal reflector 108b. Next, the layered structure is etched by, for example, dry etching using the resist pattern as a mask. This etching is continued until at least the side surface of the oxidized layer 105S is exposed (for example, until the substrate 101 is exposed). As a result, the mesa M is formed. After that, the resist pattern is removed.

[0087] In the next step S10, an oxidized constriction layer is formed (see FIG. 14A). Specifically, the mesa M (see FIG. 13B) formed in the stack is exposed to a high-temperature water vapor atmosphere to oxidize the oxidized layer 105S over a predetermined distance (e.g., several μm) from the side toward the center. As a result, the oxidized layer 105S becomes the oxidized constriction layer 105, and the mesa M becomes the mesa structure MS.

[0088] In the next step S11, the first insulating film 112 is formed (see FIG. 14B). Specifically, the first insulating film 112 is formed on the entire surface by, for example, vapor deposition, sputtering, or the like.

[0089] In the next step S12, second and third contact holes CH2 and CH3 are formed (see FIG. 15A ). Specifically, by photolithography and etching, a part of the first insulating film 112 on the substrate 101 is removed to form the second contact hole CH2 for cathode contact, and a part of the third insulating film 114 and the first insulating film 112 on the mesa structure MS is removed to form the third contact hole CH3 for anode contact.

[0090] In the next step S13, the cathode electrode 109 is formed (see FIG. 15B ). Specifically, the cathode electrode 109 is formed by, for example, a lift-off method in the region around the mesa structure MS on the upper surface of the substrate 101 so as to surround the mesa structure MS and so that the inner peripheral edge of the cathode electrode 109 overlaps the first insulating film 112.

[0091] In the next step S14, the cathode wiring 111 is formed (see FIG. 16A). Specifically, the cathode wiring 111 is formed on the cathode electrode 109 by, for example, plating. Note that, prior to the plating, it is preferable to form a seed layer at least on the cathode electrode 109.

[0092] In the next step S15, the second insulating film 113 is formed (see FIG. 16B). Specifically, the second insulating film 113 is formed on the entire surface by, for example, vapor deposition, sputtering, or the like.

[0093] In the final step S16, a fourth contact hole CH4 is formed (see FIG. 17). Specifically, a part of the second insulating film 113 on the metal reflecting mirror 108b is removed to form the fourth contact hole CH4 for anode contact.

[0094] <Effects of the Surface Light Emitting Device> The effects of the surface light emitting device 10 will be described below.

[0095] The surface-emitting element 10 has a laminated structure LS including a light-emitting layer 103 and a reflective structure 108 stacked on top of each other, the laminated structure LS having an emission surface ES on the side opposite to the reflective structure 108 side of the light-emitting layer 103, and the reflective structure 108 has a reflectance distribution in the in-plane direction.

[0096] According to the surface light emitting device 10, by having an exit surface ES on the side of the light emitting layer 103 opposite to the reflecting structure 108 side, the material of the reflecting structure 108 is not required to be optically transparent, and this increases the degree of freedom in selecting the material and structure of the reflecting structure 108. As a result, it becomes possible to increase the robustness against deviations from the design target value of the reflectance distribution of the reflecting structure 108. Specifically, for example, a hybrid mirror (more specifically, DMM) in which a dielectric multilayer reflecting mirror and a metal reflecting mirror are stacked, which are robust against film thickness / linewidth variations, can be used as the reflecting structure 108.

[0097] On the other hand, for example, in Patent Document 1, a surface relief structure is used for the reflection structure on the exit surface side, which makes it difficult to obtain a difference in reflectivity between the high-reflection and low-reflection regions, and also raises concerns about a narrow design margin for film thickness and low robustness against film thickness fluctuations. More specifically, in Patent Document 1, in order to form high-reflection and low-reflection regions on the exit surface side, the exit surface is textured with a height (depth) that is an odd multiple of λ / 4. For example, when using a GaAs-based material for an oscillation wavelength of 940 nm, λ / 4 results in a minute texture of approximately 67 nm. The process margin (assumed to be ±10%) is 6 to 7 nm, making the design margin extremely narrow. Furthermore, for example, in the case of SiN, λ / 4 is approximately 118 nm, so the process margin (assumed to be ±10%) is approximately 10 nm, making it difficult to expand the design margin even if the material is changed.

[0098] For example, Patent Document 2 uses a grating structure (groove structure) as the reflection structure on the emission surface, which narrows the design margin for linewidth and raises concerns about low robustness against linewidth fluctuations. Specifically, Patent Document 2 concentrically forms grooves of varying widths on the emission surface. The phase of the reflected light can be controlled by adjusting the width and height of the grooves. This allows the reflected light to converge or diverge, similar to a lens. Phase control (i.e., appropriate design of the groove structure) to converge the reflected light returning to the resonator can reduce the radiation angle of the emitted light. In other words, the radiation angle of the emitted light depends on the parameters of the groove structure (linewidth, step, taper angle), resulting in narrow process margins. In particular, when forming grooves by dry etching, it is difficult to align the depths of grooves with different widths due to the microloading effect. Furthermore, dust and other foreign matter entering the groove structure is difficult to remove.

[0099] Furthermore, for example, in a reference document (JP 2000-76682 A), in order to obtain a convex-curved lens on a mesa, the resist is round-baked and the shape is transferred by dry etching. In this process, the resulting shape changes significantly when the selectivity between the resist and the non-etching material (which depends on dry etching conditions such as substrate-side bias, resist patterning / aperture ratio, etc.) changes. For this reason, it is difficult to consistently obtain this convex-curved shape itself. Furthermore, it is difficult to form a stable insulating film / electrode structure for this convex-curved lens. Furthermore, due to the convex structure, there is a risk of the lens being damaged by contact with a collet during the assembly process.

[0100] The reflecting structure 108 has first and second portions 108-1 and 108-2 that differ in position and reflectance in the in-plane direction, thereby making it possible to reliably obtain a reflectance distribution (reflectance difference) in the in-plane direction.

[0101] The first portion 108-1 corresponds to the light-emitting region LA of the light-emitting layer 103, and the reflectance of the first portion 108-1 is higher than the reflectance of the second portion 108-2, which makes it possible to suppress oscillation in higher modes while giving priority to oscillation in the fundamental mode, thereby reducing the radiation angle.

[0102] The first portion 108-1 having a relatively high reflectance corresponds to the light emitting area LA of the light emitting layer 103. This allows the reflectance of the first portion 108-1 to mainly contribute to oscillation in the fundamental mode.

[0103] The second portion 108-2, which has a relatively low reflectivity, surrounds the first portion 108-1, which has a relatively high reflectivity, so that the reflectivity of the second portion 108-2 can mainly contribute to suppressing oscillation in higher-order modes.

[0104] 2. Surface Light Emitting Device According to Example 2 of an Embodiment of the Present Technology FIG. 18 is a partially enlarged cross-sectional view (corresponding to FIG. 3 ) of a surface light emitting device 20 according to Example 2 of an embodiment of the present technology.

[0105] As shown in FIG. 18, the surface-emitting device 20 has a configuration similar to that of the surface-emitting device 10 of Example 1, except that the number of layers of the dielectric film of the multilayer film reflector 108a in the first and second parts 108-1 and 108-2 of the reflection structure 108 is the same, and the first part 108-1 includes a part (upper part) of the contact layer 106.

[0106] In the surface light emitting device 20, a circumferential groove 106a is formed in a position corresponding to the second portion 108-2 of the contact layer 106, the circumferential groove 106a being circumferential in plan view.

[0107] In the surface-emitting device 20, the optical thickness of the portion of the contact layer 106 included in the first portion 108-1 (the portion surrounded by the circumferential groove 106a) is set to an odd multiple of λ / 4, and the thickness of the portion of the contact layer 106 corresponding to the second portion 108-2 is set to an even multiple of λ / 4.

[0108] The second portion 108-2 is formed such that the first and second dielectric layers 108a1 and 108a2 are partially inserted into the peripheral groove 106a in the in-plane direction.

[0109] An example of a method for manufacturing the surface light emitting device 20 will be described below with reference to the flowcharts in Figures 19 and 20 and half-side cross-sectional views of each process. The overall flow is as follows: First, a semiconductor manufacturing method using semiconductor manufacturing equipment is used to simultaneously produce a plurality of surface light emitting devices 20 on a single wafer (hereinafter, for convenience, also referred to as "substrate 101"), which is the base material of the substrate 101. Next, the series of multiple surface light emitting devices 20 are separated from each other by dicing (e.g., stealth dicing) to obtain chip-shaped surface light emitting devices 20.

[0110] In the first step S21, a stack is produced (see FIG. 21A ). Specifically, the stack is produced by stacking the first semiconductor multilayer reflector 102, the light-emitting layer 103, the second semiconductor multilayer reflector 104 having the oxidized layer 105S disposed therein, and the contact layer 106 in this order on the substrate 101 as a growth substrate by an epitaxial crystal growth method such as MOCVD (Metal Organic Chemical Vapor Deposition). The oxidized layer 105S is a compound semiconductor layer (e.g., an AlGaAs layer or an AlAs layer) that will be the material for the oxidized constriction layer 105. When producing the laminate, methyl-based organometallic gases such as trimethylaluminum (TMAl), trimethylgallium (TMGa), and trimethylindium (TMIn), and arsine (AsH) gas are used as raw materials for the compound semiconductor, disilane (SiH) is used as a raw material for the donor impurity, and carbon tetrabromide (CBr) is used as a raw material for the acceptor impurity.

[0111] In the next step S22, the contact layer 106 is half-etched (see FIG. 21B). Specifically, a part of the contact layer 106 is removed by half-etching using photolithography and etching, thereby forming a circumferential groove 106a in the contact layer 106.

[0112] In the next step S23, the anode electrode 107 is formed (see FIG. 22A ). Specifically, the anode electrode 107 is formed in a circumferential shape (e.g., a ring shape) in a planar view on the laminate (specifically, on the contact layer 106) by, for example, a lift-off method. At this time, deposition, sputtering, or the like is used to form a film of the electrode material.

[0113] In the next step S24, the first to fifth dielectric layers 108a2 to 108a5 are formed (see FIG. 22B). Specifically, the first to fifth dielectric layers 108a1 to 108a5 are formed in this order over the entire surface by, for example, vapor deposition or sputtering. As a result, the multilayer film reflecting mirror 108a is formed.

[0114] In the next step S25, a first contact hole CH1 is formed (see FIG. 23A). Specifically, a portion of the multilayer film reflector 108a is removed by photolithography and etching to form a circular first contact hole CH1 that exposes the anode electrode 107.

[0115] In the next step S26, a metal reflecting mirror 108b is formed as an anode wiring (see FIG. 23B). Specifically, a seed layer is first formed on a portion of the multilayer film reflecting mirror 108a and on the anode electrode 107, for example, by vapor deposition or sputtering. Next, a plating layer is formed on the seed layer, for example, by plating. As a result, the metal reflecting mirror 108b is formed.

[0116] In the next step S27, the third insulating film 114 is formed (see FIG. 24A). Specifically, the third insulating film 114 is formed on the entire surface by, for example, vapor deposition, sputtering, or the like.

[0117] In the next step S28, the mesa M is formed (see FIG. 24B). Specifically, first, a resist pattern for forming the mesa M is formed on the layered structure including the multilayer reflector 108a and the metal reflector 108b by photolithography. Next, the layered structure is etched by, for example, dry etching using the resist pattern as a mask. This etching is continued until at least the side surface of the oxidized layer 105S is exposed (for example, until the substrate 101 is exposed). As a result, the mesa M is formed. After that, the resist pattern is removed.

[0118] In the next step S29, an oxidized constriction layer is formed (see FIG. 25A). Specifically, the mesa M (see FIG. 24B) formed in the stack is exposed to a high-temperature water vapor atmosphere to oxidize the oxidized layer 105S over a predetermined distance (e.g., several μm) from the side toward the center. As a result, the oxidized layer 105S becomes the oxidized constriction layer 105, and the mesa M becomes the mesa structure MS.

[0119] In the next step S30, the first insulating film 112 is formed (see FIG. 25B). Specifically, the first insulating film 112 is formed on the entire surface by, for example, vapor deposition, sputtering, or the like.

[0120] In the next step S31, second and third contact holes CH2 and CH3 are formed (see FIG. 26A ). Specifically, by photolithography and etching, a part of the first insulating film 112 on the substrate 101 is removed to form the second contact hole CH2 for cathode contact, and a part of the third insulating film 114 and the first insulating film 112 on the mesa structure MS is removed to form the third contact hole CH3 for anode contact.

[0121] In the next step S32, the cathode electrode 109 is formed (see FIG. 26B ). Specifically, the cathode electrode 109 is formed by, for example, a lift-off method in the region around the mesa structure MS on the upper surface of the substrate 101 so as to surround the mesa structure MS and so that the inner peripheral edge of the cathode electrode 109 overlaps the first insulating film 112.

[0122] In the next step S33, the cathode wiring 111 is formed (see FIG. 27A). Specifically, the cathode wiring 111 is formed on the cathode electrode 109 by, for example, plating. Note that, prior to the plating, it is preferable to form a seed layer at least on the cathode electrode 109.

[0123] In the next step S34, the second insulating film 113 is formed (see FIG. 27B). Specifically, the second insulating film 113 is formed on the entire surface by, for example, vapor deposition, sputtering, or the like.

[0124] In the final step S35, a fourth contact hole CH4 is formed (see FIG. 28). Specifically, a part of the second insulating film 113 on the metal reflecting mirror 108b is removed to form the fourth contact hole CH4 for anode contact.

[0125] According to the surface-emitting device 20, a portion (upper portion) of the contact layer 106 in the first portion 108-1 essentially becomes a refractive index layer, so that the number of refractive index layers in the first portion 108-1 is an odd number more than the number of refractive index layers in the second portion 108-2, and as a result, the same effect as that of the surface-emitting device 10 in Example 1 is obtained.

[0126] 3. Surface Light Emitting Device According to Example 3 of an Embodiment of the Present Technology FIG. 29 is a partially enlarged cross-sectional view (corresponding to FIG. 3) of a surface light emitting device 30 according to Example 3 of an embodiment of the present technology.

[0127] As shown in FIG. 29, the surface light emitting device 30 has a configuration generally similar to that of the surface light emitting device 20 according to the second embodiment, except that the reflecting structure 108 does not have a multilayer film reflector 108a.

[0128] In the surface-emitting device 30, the optical thickness of the portion of the contact layer 106 included in the first portion 108-1 (the portion surrounded by the circumferential groove 106a) is set to an odd multiple of λ / 4, and the thickness of the portion of the contact layer 106 corresponding to the second portion 108-2 is set to an even multiple of λ / 4.

[0129] In the surface light emitting device 30, a part of the metal reflector 108b included in the first portion 108-1 is provided on the part surrounded by the circumferential groove 106a of the contact layer 106, and the other part of the metal reflector 108b included in the second portion 108-1 is embedded in the circumferential groove 106a.

[0130] An example of a method for manufacturing the surface light emitting device 30 will be described below with reference to the flowcharts in Figures 30 and 31 and half-side cross-sectional views of each process. The overall flow is as follows: First, a semiconductor manufacturing method using semiconductor manufacturing equipment is used to simultaneously produce a plurality of surface light emitting devices 30 on a single wafer (hereinafter, also referred to as "substrate 101" for convenience) that is the base material of the substrate 101. Next, the series of surface light emitting devices 30 are separated from one another by dicing (e.g., stealth dicing) to obtain chip-shaped surface light emitting devices 30.

[0131] In the first step S41, a stack is produced (see FIG. 32A ). Specifically, the stack is produced by stacking the first semiconductor multilayer reflector 102, the light-emitting layer 103, the second semiconductor multilayer reflector 104 having the oxidized layer 105S disposed therein, and the contact layer 106 in this order on the substrate 101 as a growth substrate by an epitaxial crystal growth method such as MOCVD (Metal Organic Chemical Vapor Deposition). The oxidized layer 105S is a compound semiconductor layer (e.g., an AlGaAs layer or an AlAs layer) that will be the material for the oxidized constriction layer 105. When producing the laminate, methyl-based organometallic gases such as trimethylaluminum (TMAl), trimethylgallium (TMGa), and trimethylindium (TMIn), and arsine (AsH) gas are used as raw materials for the compound semiconductor, disilane (SiH) is used as a raw material for the donor impurity, and carbon tetrabromide (CBr) is used as a raw material for the acceptor impurity.

[0132] In the next step S42, the contact layer 106 is half-etched (see FIG. 32B). Specifically, a part of the contact layer 106 is removed by half-etching using photolithography and etching to form the circumferential groove 106a.

[0133] In the next step S43, a metal reflector 108b is formed as the anode electrode wiring (see FIG. 33A). Specifically, first, a seed layer is formed on the part of the contact layer 106 where the circumferential groove 106a is formed, for example, by vapor deposition or sputtering. Next, a plating layer is formed on the seed layer, for example, by plating. As a result, the metal reflector 108b as the anode electrode wiring is formed.

[0134] In the next step S44, the third insulating film 114 is formed (see FIG. 33B). Specifically, the third insulating film 114 is formed on the entire surface by, for example, vapor deposition, sputtering, or the like.

[0135] In the next step S45, the mesa M is formed (see FIG. 34A). Specifically, first, a resist pattern for forming the mesa M is formed by photolithography on the layered structure on which the metal reflector 108b has been formed. Next, the layered structure is etched by, for example, dry etching using the resist pattern as a mask. This etching is carried out until at least the side surface of the oxidized layer 105S is exposed (for example, until the substrate 101 is exposed). As a result, the mesa M is formed. After that, the resist pattern is removed.

[0136] In the next step S46, an oxidized constriction layer is formed (see FIG. 34B). Specifically, the mesa M (see FIG. 34A) formed in the stack is exposed to a high-temperature water vapor atmosphere to oxidize the oxidized layer 105S over a predetermined distance (e.g., several μm) from the side toward the center. As a result, the oxidized layer 105S becomes the oxidized constriction layer 105, and the mesa M becomes the mesa structure MS.

[0137] In the next step S47, the first insulating film 112 is formed (see FIG. 35A). Specifically, the first insulating film 112 is formed on the entire surface by, for example, vapor deposition, sputtering, or the like.

[0138] In the next step S48, second and third contact holes CH2 and CH3 are formed (see FIG. 35B ). Specifically, by photolithography and etching, a part of the first insulating film 112 on the substrate 101 is removed to form the second contact hole CH2 for cathode contact, and a part of the third insulating film 114 and the first insulating film 112 on the mesa structure MS is removed to form the third contact hole CH3 for anode contact.

[0139] In the next step S49, the cathode electrode 109 is formed (see FIG. 36A ). Specifically, the cathode electrode 109 is formed by, for example, a lift-off method in the region around the mesa structure MS on the upper surface of the substrate 101 so as to surround the mesa structure MS and so that the inner peripheral edge of the cathode electrode 109 overlaps the first insulating film 112.

[0140] In the next step S50, the cathode wiring 111 is formed (see FIG. 36B ). Specifically, the cathode wiring 111 is formed on the cathode electrode 109 by, for example, plating. Note that, prior to the plating method, it is preferable to form a seed layer at least on the cathode electrode 109.

[0141] In the next step S51, the second insulating film 113 is formed (see FIG. 37A). Specifically, the second insulating film 113 is formed on the entire surface by, for example, vapor deposition, sputtering, or the like.

[0142] In the final step S52, a fourth contact hole CH4 is formed (see FIG. 37B). Specifically, a part of the second insulating film 113 on the metal reflecting mirror 108b is removed to form the fourth contact hole CH4 for anode contact.

[0143] According to the surface-emitting device 30, a portion (upper portion) of the contact layer 106 in the first portion 108-1 essentially becomes a refractive index layer, so that the number of refractive index layers in the first portion 108-1 is an odd number more than the number of refractive index layers in the second portion 108-2, and as a result, the same effect as that of the surface-emitting device 10 in Example 1 is obtained.

[0144] 4. Surface Light Emitting Device According to Example 4 of an Embodiment of the Present Technology FIG. 38 is a partially enlarged cross-sectional view of a surface light emitting device 40 according to Example 4 of an embodiment of the present technology.

[0145] As shown in FIG. 38, the surface-emitting device 40 has a configuration generally similar to that of the surface-emitting device 10 of Example 1, except that in the reflection structure 108, the reflectances of the multilayer film reflectors 108a of the first and second parts 108-1, 108-2 are the same, and the reflectances of the metal reflectors 108b of the first and second parts 108-1, 108-2 are different.

[0146] In the surface light emitting device 40, first to fifth dielectric layers 108a1 to 108a5 and a metal reflector 108b are laminated in this order on the upper surface (flat surface) of the contact layer 106.

[0147] The number of refractive index layers in the multilayer film reflector 108a of the first and second portions 108-1 and 108-2 is the same. The metal reflector 108b of the first portion 108-1 (hereinafter also referred to as the "metal reflector central portion") and the metal reflector 108b of the second portion 108-2 (hereinafter also referred to as the "metal reflector peripheral portion") are made of different metals. Here, the metal materials of the metal reflector central portion and the metal reflector peripheral portion are selected so that the reflectance of the metal reflector central portion is higher than the reflectance of the metal reflector peripheral portion. For example, the plating layer 108b21 of the metal reflector central portion may be made of silver, and the plating layer 108b22 of the metal reflector peripheral portion may be made of gold or copper.

[0148] That is, in the surface light emitting element 40, the reflectance of the first portion 108-1 is higher than the reflectance of the second portion 108-2.

[0149] According to the surface light emitting device 40, the same effects as those of the surface light emitting device 10 according to the first embodiment can be obtained.

[0150] In the surface-emitting device 40, the reflectance of the first portion 108-1 may be lower than that of the second portion 108-2 by making the reflectance of the central portion of the metal reflector lower than that of the peripheral portion of the metal reflector. This allows for oscillation of a higher-order mode more predominantly than the fundamental mode, thereby widening the radiation angle (NA). For example, the plating layer 108b21 in the central portion of the metal reflector may be made of gold or copper, and the plating layer 108b22 in the peripheral portion of the metal reflector may be made of silver.

[0151] 5. Surface light emitting device according to example 5 of an embodiment of the present technology> Fig. 39 is a partially enlarged cross-sectional view (part 1) of a surface light emitting device 50 according to example 5 of an embodiment of the present technology. Fig. 40 is a partially enlarged cross-sectional view (part 2) of a surface light emitting device 50 according to example 5 of an embodiment of the present technology. Fig. 41 is a plan view of the surface light emitting device 50 according to example 5 of an embodiment of the present technology. Fig. 39 is a cross-sectional view taken along line 39-39 in Fig. 41 . Fig. 40 is a cross-sectional view taken along line 40-40 in Fig. 41 .

[0152] As shown in FIGS. 39 to 41, the surface light emitting device 50 has a configuration generally similar to that of the surface light emitting device 10 according to the first embodiment, except that it has a mesare-less structure.

[0153] 39 and 41, in the surface light emitting device 50, a plurality of (for example, six) trenches T (defective portions) are provided in the upper surface of the stacked structure LS so as to surround the second portion 108-2 of the reflecting structure 108 in plan view. Each trench T has the function of exposing the side surface of the oxidized layer during the oxidation step.

[0154] An ion implantation region IIA having a circular shape in plan view is provided inside the region of the stacked structure LS where the plurality of trenches T are formed, for suppressing current leakage.

[0155] 39 , a cathode electrode 109 is provided on the bottom surface of each trench T, and a cathode wiring 111 is provided on the cathode electrode 109. The cathode wiring 111 extends along the side surface of the trench T opposite to the light emitting region side, via first and second insulating films 112 and 113. The extending portion of the cathode wiring 111 is electrically connected to the cathode terminal of the driver.

[0156] According to the surface light emitting device 50, the same effects as those of the surface light emitting device 10 according to the first embodiment can be obtained.

[0157] 6. Surface Light Emitting Device According to Example 6 of an Embodiment of the Present Technology FIG. 42 is a partially enlarged cross-sectional view of a surface light emitting device 60 according to Example 6 of an embodiment of the present technology.

[0158] As shown in FIG. 42, the surface light emitting device 60 has the same configuration as the surface light emitting device 10 according to the first embodiment, except that the reflectance relationship between the first and second portions 108-1 and 108-2 in the reflective structure 108 is reversed.

[0159] In the surface light emitting device 60, the reflectance of the second portion 108-2 of the reflective structure 108 is higher than the reflectance of the first portion 108-1.

[0160] In detail, the reflectance of the multilayer reflector 108a (peripheral part of the multilayer reflector) in the second part 108-2 is higher than the reflectance of the multilayer reflector 108a (central part of the multilayer reflector) in the first part 108-1, and the reflectance of the metal reflector 108b (central part of the metal reflector) in the first part 108-1 is the same as the reflectance of the metal reflector 108b (peripheral part of the metal reflector) in the second part 108-2.

[0161] Specifically, as an example, the central portion of the multilayer reflector has a four-layer dielectric structure, and the peripheral portion of the multilayer reflector has a five-layer dielectric structure.

[0162] According to the surface light emitting device 60, it is possible to oscillate in a higher order mode more predominantly than in the fundamental mode, and therefore it is possible to widen the radiation angle.

[0163] 7. Surface Light Emitting Device According to Example 7 of an Embodiment of the Present Technology FIG. 43 is a cross-sectional view of a surface light emitting device 70 according to Example 7 of an embodiment of the present technology.

[0164] As shown in Figure 43, the surface-emitting device 70 has a configuration similar to that of the surface-emitting device 10 of Example 1, except that in the reflection structure 108, the reflectivity of the central part of the multilayer film reflector is the same as the reflectivity of the peripheral part of the multilayer film reflector, and the metal reflector 108b is not included in the second part 108-2.

[0165] In the surface-emitting device 70, the number of refractive index layers in the central portion of the multilayer reflector is the same as the number of refractive index layers in the peripheral portion of the multilayer reflector, and the metal reflector 108b does not have a peripheral portion of the metal reflector. Here, the metal reflector 108b has a central portion of the metal reflector and an anode wiring portion on the anode electrode 107 that are separate entities.

[0166] According to the surface light emitting device 70, the same effects as those of the surface light emitting device 10 according to the first embodiment can be obtained.

[0167] 8. Surface Light Emitting Device According to Example 8 of an Embodiment of the Present Technology FIG. 44 is a cross-sectional view of a surface light emitting device 80 according to Example 8 of an embodiment of the present technology.

[0168] As shown in Figure 44, the surface-emitting device 80 has a configuration similar to that of the surface-emitting device 10 of Example 1, except that in the reflection structure 108, the reflectivity of the central part of the multilayer film reflector is the same as the reflectivity of the peripheral part of the multilayer film reflector, and the metal reflector 108b is not included in the first part 108-1.

[0169] In the surface-emitting device 80, the number of refractive index layers in the central portion of the multilayer reflector is the same as the number of refractive index layers in the peripheral portion of the multilayer reflector, and the metal reflector 108b does not have a central portion of the metal reflector. Here, the metal reflector 108b is integrated with the peripheral portion of the metal reflector and the anode wiring portion on the anode electrode 107.

[0170] According to the surface light emitting device 80, the reflectance of the second portion 108-1 is higher than that of the first portion 108-1, and the higher order mode can be oscillated more predominantly than the fundamental mode, thereby widening the radiation angle.

[0171] 9. Surface Light Emitting Device According to Example 9 of an Embodiment of the Present Technology FIG. 45 is a cross-sectional view of a surface light emitting device 90 according to Example 9 of an embodiment of the present technology.

[0172] As shown in FIG. 45, the surface light emitting device 90 has a configuration generally similar to that of the surface light emitting device 10 according to the first embodiment, except that the anode electrode 107 is solid.

[0173] In the surface light emitting device 90, a solid anode electrode 107 is disposed on the contact layer 106, a multilayer film reflector 108a is disposed on the anode electrode 107 except for its outer periphery, and a metal reflector 108b is disposed on the multilayer film reflector 108a except for its outer periphery. The outer periphery of the metal reflector 108b and the outer periphery of the anode electrode 107 are in contact with each other.

[0174] In the surface light emitting device 90, the anode electrode 107 can also function as a metallic reflector, and can therefore be a component of the reflecting structure 108.

[0175] According to the surface light emitting device 90, the same effects as those of the surface light emitting device 10 according to the first embodiment can be obtained.

[0176] In the surface light emitting element 90, the reflectance of the first portion 108-1 may be higher or lower than the reflectance of the first portion 108-2.

[0177] 10. Surface Light Emitting Device According to Example 10 of an Embodiment of the Present Technology FIG. 46 is a cross-sectional view of a surface light emitting device 100 according to Example 10 of an embodiment of the present technology.

[0178] As shown in Figure 46, the surface-emitting device 100 has a configuration generally similar to that of the surface-emitting device 90 of Example 9, except that in the reflection structure 108, the multilayer film reflector 108a does not have a peripheral portion of the multilayer film reflector.

[0179] According to the surface light emitting device 100, the same effects as those of the surface light emitting device 10 according to the first embodiment can be obtained.

[0180] In the surface light emitting device 100, the reflectance of the first portion 108-1 may be higher or lower than the reflectance of the first portion 108-2.

[0181] 11. Surface Light Emitting Device According to Example 11 of an Embodiment of the Present Technology FIG. 47 is a cross-sectional view of a surface light emitting device 110 according to Example 11 of an embodiment of the present technology.

[0182] As shown in FIG. 47, the surface light emitting device 110 has a configuration generally similar to that of the surface light emitting device 90 according to Example 9, except that the reflecting structure 108 does not have a central metal reflecting mirror.

[0183] In the surface light emitting device 110, the reflecting structure 108 has a multilayer reflector central portion, a multilayer reflector peripheral portion, and a metal reflector peripheral portion.

[0184] In the surface light emitting element 110, the reflectance of the first portion 108-1 may be higher or lower than the reflectance of the first portion 108-2.

[0185] 12. Surface Light Emitting Device According to Example 12 of an Embodiment of the Present Technology FIG. 48 is a cross-sectional view of a surface light emitting device 120 according to Example 12 of an embodiment of the present technology.

[0186] As shown in FIG. 48, the surface light emitting device 120 has a configuration generally similar to that of the surface light emitting device 90 according to Example 9, except that the reflecting structure 108 does not have a central metal reflecting mirror or a peripheral multilayer film reflecting mirror.

[0187] In the surface light emitting device 120, the reflecting structure 108 has a multilayer film reflector central portion and a metal reflector peripheral portion.

[0188] In the surface light emitting element 120, the reflectance of the first portion 108-1 may be lower or higher than the reflectance of the first portion 108-2.

[0189] 13. Surface Light Emitting Device According to Example 13 of an Embodiment of the Present Technology FIG. 49 is a cross-sectional view of a surface light emitting device 130 according to Example 13 of an embodiment of the present technology.

[0190] As shown in Figure 49, the surface light emitting element 130 has the same configuration as the surface light emitting element 10 of Example 1, except that the substrate 101 has an opening 101a as an emission port at a position corresponding to the light emitting region.

[0191] In the surface light emitting device 130, the surface (lower surface) of the first semiconductor multilayer film reflector 102 opposite to the light emitting layer 103 side serves as an emission surface ES.

[0192] According to the surface-emitting element 130, the same effect as that of the surface-emitting element 10 of Example 1 can be obtained, and since the substrate 101 has an opening 101a as an emission port, light absorption can be suppressed, and thus a decrease in the output of the emitted light (laser light) can be suppressed.

[0193] 14. Surface Light Emitting Device According to Example 14 of an Embodiment of the Present Technology FIG. 50 is a cross-sectional view of a surface light emitting device 140 according to Example 14 of an embodiment of the present technology.

[0194] As shown in Figure 50, the surface-emitting element 140 has a configuration generally similar to that of the surface-emitting element 10 of Example 1, except that it is a surface-emitting type surface-emitting element in which the reflective structure 108 is provided on the back surface (lower surface) of the substrate 101.

[0195] In the surface light emitting device 140, a multilayer film reflector 108a and a metal reflector 108b are laminated in this order on the back surface of the substrate 101.

[0196] In the surface light emitting element 140, the surface of the laminated structure LS opposite to the substrate 101 side (for example, the upper surface of the first insulating film 112) serves as the emission surface ES.

[0197] According to the surface light emitting device 140, it is possible to realize a surface emission type surface light emitting device (specifically, a surface emission type VCSEL) that can obtain the same effects as the surface light emitting device 10 according to the first embodiment.

[0198] 15. Surface Light Emitting Device According to Example 15 of an Embodiment of the Present Technology FIG. 51 is a cross-sectional view of a surface light emitting device 150 according to Example 15 of an embodiment of the present technology.

[0199] As shown in Figure 51, the surface light emitting device 150 has a configuration generally similar to that of the surface light emitting device 140 of Example 14, except that it has a back electrode structure in which the cathode electrode wiring is provided on the back surface of the substrate 101.

[0200] In the surface light emitting element 150, the metal reflecting mirror 108b of the reflecting structure 108 also functions as a cathode electrode wiring. The surface light emitting element 150 does not have a cathode electrode 109, a cathode wiring 111, or second and third insulating films 113 and 114.

[0201] In the surface light emitting device 150, a multilayer film reflector 108a is disposed on the back surface of the substrate 101, and a central metal reflector portion and a peripheral metal reflector portion are disposed on the multilayer film reflector 108a. The metal reflector 108b further has a peripheral metal reflector portion that extends radially outward from the peripheral metal reflector portion. The peripheral metal reflector portion is disposed on the back surface of the substrate 101.

[0202] In the surface light emitting element 150, the surface of the laminated structure LS opposite to the substrate 101 side (for example, the upper surface of the first insulating film 112) serves as the emission surface ES.

[0203] The surface-emitting device 150 can provide the same effects as the surface-emitting device 10 according to the first embodiment, and is a surface-emitting type surface-emitting device with a back electrode (more specifically, a surface-emitting type VCSEL with a back electrode).

[0204] 16. Surface Light Emitting Device According to Example 16 of an Embodiment of the Present Technology FIG. 52 is a cross-sectional view of a surface light emitting device 170 according to Example 16 of an embodiment of the present technology.

[0205] As shown in FIG. 52, the surface light emitting device 170 constitutes a surface light emitting device array including a plurality of surface light emitting devices 10 arranged in an array (for example, a staggered pattern, a matrix pattern, etc.).

[0206] For example, the plurality of surface light emitting elements 10 share the cathode wiring 111 and the substrate 101 .

[0207] In the surface light emitting device 170, the plurality of surface light emitting devices 10 have an electrode layout in which the anodes are independent and the cathode is shared, and each surface light emitting device 10 can be driven independently.

[0208] In the surface light emitting element 170, the radiation angle can be made different between the surface light emitting elements 10 by making the reflectance distribution in the in-plane direction of the reflective structure 108 different between the surface light emitting elements 10.

[0209] The surface light emitting device 170 can obtain a very high total output and can be adapted to point light irradiation, etc. Note that any of the surface light emitting devices of Examples 2 to 16 may be arranged in an array to form a surface light emitting device array.

[0210] 17. Surface Light Emitting Device According to Example 17 of an Embodiment of the Present Technology FIG. 53 is a cross-sectional view of a surface light emitting device 180 according to Example 17 of an embodiment of the present technology.

[0211] Multi-junction VCSELs, for example, in which two or more pn junctions are stacked and separated by tunnel junctions, can achieve higher power and electrical-to-optical conversion efficiency. Furthermore, the multi-junction structure can further shorten the rise / fall time of laser oscillation, enabling shorter pulse emission. This technology is therefore extremely important for time-of-flight applications, as it can extend the measurable distance without compromising eye safety. However, multi-junction VCSELs are prone to multi-mode oscillation in the transverse direction, which can result in a large radiation angle (NA) of the emitted light. Therefore, applying this technology to multi-junction VCSELs is extremely effective.

[0212] As shown in FIG. 53, the surface light emitting device 180 has a configuration generally similar to that of the surface light emitting device 10 according to the first embodiment, except that it has a multi-junction structure.

[0213] The surface light emitting device 180 includes a plurality of (e.g., two) light emitting layers 103 stacked one on top of the other between the first and second semiconductor multilayer film reflectors 102, 104, and a tunnel junction layer 115 disposed between the two light emitting layers 103. A first cladding layer 116 (e.g., an n-AlGaAs layer with an Al composition of 0.4) is disposed between the tunnel junction layer 115 and the light emitting layer 103 above it. A second cladding layer 117 (e.g., a p-AlGaAs layer with an Al composition of 0.4) is disposed between the tunnel junction layer 115 and the light emitting layer 103 below it.

[0214] The tunnel junction layer 115 includes a p-type semiconductor region and an n-type semiconductor region stacked on top of each other. Here, the p-type semiconductor region is disposed on the substrate 101 side (below) of the n-type semiconductor region. The p-type semiconductor region is, for example, a highly doped p-type layer (e.g., a p-GaAs layer, a p-InGaAs layer, etc.) doped with a high concentration of p-type impurities. The n-type semiconductor region is, for example, a highly doped n-type layer (e.g., an n-GaAs layer, an n-InGaAs layer, etc.) doped with a high concentration of n-type impurities. The tunnel junction layer 115 allows currents of the same magnitude to flow through the two light-emitting layers 103.

[0215] The surface light emitting device 180 can provide the same effects as the surface light emitting device 10 according to the first embodiment, and can realize a high-output surface light emitting device (more specifically, a high-output back-emitting VCSEL).

[0216] The surface light emitting device 180 may have three or more light emitting layers stacked on top of each other. In this case, it is also preferable to provide a tunnel junction layer between at least one pair of two light emitting layers adjacent in the direction perpendicular to the surface. The surface light emitting device 180 may have multiple current confinement layers (e.g., oxide confinement layers) stacked on top of each other. In this case, it is preferable to provide an oxide confinement layer for each light emitting layer.

[0217] 18. Surface Light Emitting Device According to Example 18 of an Embodiment of the Present Technology FIG. 54 is a plan view of a surface light emitting device 190 according to Example 18 of an embodiment of the present technology.

[0218] As shown in Figure 54, the surface-emitting device 190 has a configuration similar to that of the surface-emitting device 10 of Example 1, except that the outer peripheral shape of the first portion 108-1 (the inner peripheral shape of the second portion 108-2) in the reflective structure 108 is anisotropic.

[0219] In the surface light emitting device 190, the outer peripheral shape of the first portion 108-1 is, for example, elliptical.

[0220] According to the surface light emitting device 190, the same effects as those of the surface light emitting device 10 according to the first embodiment can be obtained, and the surface light emitting device 190 also has excellent polarization controllability.

[0221] 19. Surface Light Emitting Device According to Example 19 of an Embodiment of the Present Technology FIG. 55 is a plan view of a surface light emitting device 200 according to Example 19 of an embodiment of the present technology.

[0222] As shown in Figure 55, the surface-emitting device 200 has a configuration similar to that of the surface-emitting device 10 of Example 1, except that the outer peripheral shape of the first portion 108-1 (the inner peripheral shape of the second portion 108-2) in the reflective structure 108 is anisotropic.

[0223] In the surface light emitting device 200, the outer periphery of the first portion 108-1 is, for example, rectangular (oblong).

[0224] According to the surface light emitting device 200, the same effects as those of the surface light emitting device 10 according to the first embodiment can be obtained, and the surface light emitting device 200 also has excellent polarization controllability.

[0225] 20. Surface Light Emitting Device According to Twentyth Example of an Embodiment of the Present Technology FIG. 56 is a cross-sectional view of a surface light emitting device 210 according to a twentieth example of an embodiment of the present technology.

[0226] As shown in FIG. 56, the surface light emitting device 210 has a configuration that is generally similar to that of the surface light emitting device 10 according to the first embodiment, except that the reflecting structure 108 does not have a metal reflecting mirror 108b.

[0227] In the surface light emitting device 210, the reflecting structure 108 is composed of a multilayer film reflecting mirror 108a.

[0228] In the surface light emitting element 210, for example, the number of refractive index layers of the multilayer film reflector 108a is greater than that of the surface light emitting element 10 according to the first embodiment.

[0229] Although the surface light emitting element 210 does not have an anode wiring, the manufacturing process can be simplified and the same effects as those of the surface light emitting element 10 according to the first embodiment can be obtained.

[0230] 21. Surface Light Emitting Device According to Example 21 of an Embodiment of the Present Technology FIG. 57 is a cross-sectional view of a surface light emitting device 220 according to Example 21 of an embodiment of the present technology.

[0231] As shown in Figure 57, the surface-emitting device 220 has a configuration similar to that of the surface-emitting device 10 of Example 1, except that an ion-implanted region IIA is provided in the stacked structure LS as a current confinement layer instead of the oxide confinement layer 105.

[0232] In the surface light emitting device 220, a circular ion implantation region IIA is provided in the stacked structure LS so as to surround the light emitting region LA in a plan view. The ion implantation region IIA (the dark black portion in FIG. 58 ) is provided, for example, at least in the region from the upper surface of the stacked structure LS to the upper surface of the light emitting layer 103 (for example, within the first semiconductor multilayer film reflector 102).

[0233] According to the surface light emitting device 220, although the light confinement effect is inferior, the same effect as that of the surface light emitting device 10 according to the first embodiment can be obtained.

[0234] 22. Modifications of the Present Technology The present technology is not limited to the examples of the above-described embodiment, and can be modified as appropriate.

[0235] For example, as in the refractive index profile shown in Figure 58, the dielectric multilayer reflector serving as the multilayer reflector 108a may be composed of three or more types (e.g., five types) of dielectric layers (refractive index layers) with different refractive indices.

[0236] In the above-described embodiments and modifications, a GaAs-based surface-emitting device (a material system lattice-matched to GaAs) has been mainly described, but the present technology is not limited thereto and can also be applied to, for example, an InP-based surface-emitting device (a material system lattice-matched to InP), a GaN-based surface-emitting device (a material system lattice-matched to GaN), etc. Examples of InP-based devices include AlGaInP-based, AlGaInAs-based, and AlInAs-based devices.

[0237] In other words, the surface-emitting device according to the present technology can use any material that emits light at any wavelength within the wavelength band of 200 to 2000 nm. The present technology can also be applied to surface-emitting devices other than surface-emitting lasers (for example, light-emitting diodes).

[0238] The laminated structure LS is not limited to a semiconductor multilayer film reflector, and may include a reflector made of one or a combination of two or more materials selected from semiconductors, dielectrics, and metals.

[0239] In the surface light emitting devices according to the above-described embodiments and modifications, the conductivity types (p-type and n-type) of the first and second semiconductor structures may be reversed. In this case, however, the positional relationship between the anode electrode and the cathode electrode must also be reversed.

[0240] Parts of the configurations of the surface light emitting devices according to the above-described embodiments and modifications may be combined within a range that does not contradict each other.

[0241] In each of the above-described embodiments and modifications, the arrangement, material, conductivity type, thickness, width, numerical value, shape, size, etc. of each layer constituting the surface-emitting device can be appropriately changed within the range in which the surface-emitting device functions.

[0242] 23. Application Examples to Electronic Devices The technology according to the present disclosure (the present technology) can be applied to various products (electronic devices). For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, or a robot, a low-power device (e.g., a smartphone, a smartwatch, a tablet, a mouse, a laptop computer, etc.), or a wireless or wired communication device.

[0243] The surface light emitting device according to the present technology can also be applied as a light source for devices that form or display images using light (for example, printers, copiers, projectors, head-mounted displays, head-up displays, etc.).

[0244] 24. Example of Application of Surface Light Emitting Device to Distance Measuring Device An application example of the surface light emitting device 10 according to Example 1 of an embodiment of the present technology will be described below.

[0245] 59 illustrates an example of a schematic configuration of a distance measurement device 1000 (distance measuring device) including the surface light emitting element 10 according to Example 1, as an example of an electronic device according to the present technology. The distance measurement device 1000 measures the distance to a subject S by a TOF (Time Of Flight) method. The distance measurement device 1000 includes the surface light emitting element 10. The distance measurement device 1000 includes, for example, the surface light emitting element 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.

[0246] The light receiving device 125 receives light emitted from the surface light emitting device 10 and reflected by the subject S (object). That is, the light receiving device 125 detects the light reflected by the subject S. The lens 128 is a lens, such as a collimating lens, for converting the light emitted from the surface light emitting device 10 into parallel light. The lens 138 is a lens, such as a condensing lens, for collecting the light reflected by the subject S and guiding it to the light receiving device 125.

[0247] 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 an output signal from a detection unit that directly detects the output of the surface-emitting device 10. The control unit 155 is, for example, a processor that controls the surface-emitting device 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 that measures 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 the 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.

[0248] In this application example, instead of the surface light emitting element 10 of Example 1, surface light emitting elements 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, and 220 can also be applied to the distance measurement device 1000.

[0249] 25. Example of Mounting Distance Measuring Device on a Moving Body FIG. 60 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving body control system to which the technology according to the present disclosure can be applied.

[0250] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 60, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 12053.

[0251] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0252] The body system control unit 12020 controls the operation of various devices equipped in 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 device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0253] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, a distance measurement device 12031 is connected to the outside-vehicle information detection unit 12030. The distance measurement device 12031 includes the above-described distance measurement device 1000. The outside-vehicle information detection unit 12030 causes the distance measurement device 12031 to measure the distance to an object outside the vehicle (subject S) and acquires the distance data obtained thereby. The outside-vehicle information detection unit 12030 may perform object detection processing for people, cars, obstacles, signs, etc. based on the acquired distance data.

[0254] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

[0255] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle 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 the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0256] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0257] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching from high beams to low beams.

[0258] The audio / video output unit 12052 transmits at least one output signal of audio and / or video to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle of information. In the example of Fig. 60, the output devices are exemplified by 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 on-board display and a head-up display.

[0259] FIG. 61 is a diagram showing an example of the installation position of the distance measurement device 12031.

[0260] In FIG. 61, a vehicle 12100 has distance measurement devices 12101, 12102, 12103, 12104, and 12105 as a distance measurement device 12031.

[0261] Distance measuring devices 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of vehicle 12100. Distance measuring device 12101 provided on the front nose and distance measuring device 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire data ahead of vehicle 12100. Distance measuring devices 12102 and 12103 provided on the side mirrors mainly acquire data on the sides of vehicle 12100. Distance measuring device 12104 provided on the rear bumper or back door mainly acquires data behind vehicle 12100. The forward data acquired by distance measuring devices 12101 and 12105 is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, etc.

[0262] 61 shows an example of the detection ranges of the distance measuring devices 12101 to 12104. Detection range 12111 indicates the detection range of the distance measuring device 12101 provided on the front nose, detection ranges 12112 and 12113 indicate the detection ranges of the distance measuring devices 12102 and 12103 provided on the side mirrors, respectively, and detection range 12114 indicates the detection range of the distance measuring device 12104 provided on the rear bumper or back door.

[0263] For example, based on the distance data obtained from the distance measuring devices 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the detection ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which runs autonomously without relying on driver operation.

[0264] For example, based on the distance data obtained from the distance measuring devices 12101 to 12104, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes 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 risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0265] The above describes an example of a mobile object control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the distance measurement device 12031 of the above-described configuration.

[0266] The present technology may also be configured as follows. (1) A surface-emitting device including a stacked structure including a light-emitting layer and a reflection structure stacked on top of each other, the stacked structure having an emission surface on the side of the light-emitting layer opposite to the reflection structure side, and the reflection structure having a reflectance distribution in an in-plane direction. (2) The surface-emitting device according to (1), wherein the reflection structure has first and second portions having different positions and reflectances in the in-plane direction. (3) The surface-emitting device according to (2), wherein the first portion corresponds to a light-emitting region of the light-emitting layer. (4) The surface-emitting device according to (2) or (3), wherein the second portion surrounds the first portion. (5) The surface-emitting device according to any one of (2) to (4), wherein the reflectance of the first portion is lower than the reflectance of the second portion. (6) The surface-emitting device according to any one of (2) to (4), wherein the reflectance of the first portion is higher than the reflectance of the second portion. (7) The surface-emitting device according to any one of (2) to (6), wherein the reflection structure includes a multilayer film reflector having a plurality of stacked refractive index layers, the multilayer film reflector being included in at least one of the first and second portions. (8) The surface-emitting device according to (7), wherein the multilayer film reflector is included in the first or second portion. (9) The surface-emitting device according to (7), wherein the multilayer film reflector is included in the first and second portions. (10) The surface-emitting device according to (9), wherein the reflectance of the multilayer film reflector in the first portion is different from the reflectance of the multilayer film reflector in the second portion. (11) The surface-emitting device according to (10), wherein the number of refractive index layers of the multilayer film reflector in the first portion is different from the number of refractive index layers of the multilayer film reflector in the second portion. (12) The surface-emitting device according to any one of (7) to (11), wherein the multilayer film reflector is a dielectric multilayer film reflector. (13) The surface light emitting device according to any one of (2) to (12), wherein the reflective structure has a metal reflector included in at least one of the first and second portions. (14) The surface light emitting device according to (13), wherein the metal reflector is included in the first portion or the second portion. (15) The surface light emitting device according to (13), wherein the metal reflector is included in the first portion and the second portion. (16) The surface light emitting device according to (15), wherein the reflectance of the metal reflector in the first portion is different from the reflectance of the metal reflector in the second portion.(17) The surface-emitting device according to any one of (13) to (16), wherein the metal reflector also serves as an electrode and / or wiring. (18) The surface-emitting device according to any one of (2) to (17), wherein the reflection structure includes: a multilayer film reflector in which a plurality of refractive index layers are stacked and which is included in at least one of the first and second portions; and a metal reflector included in at least one of the first and second portions. (19) The surface-emitting device according to any one of (2) to (18), further comprising: a reflector arranged on the side of the light-emitting layer opposite to the reflection structure side; and wherein the lower of the reflectivities of the first and second portions is lower than the reflector. (20) The surface-emitting device according to any one of (2) to (19), further comprising: a reflector arranged on the side of the light-emitting layer opposite to the reflection structure side; and wherein the reflector's reflectance is the lowest of the reflectivities of the first and second portions and the reflector. (21) The surface-emitting device according to any one of (3) to (20), wherein the laminated structure further includes a current constriction layer laminated with the light-emitting layer and the reflection structure and setting the light-emitting region. (22) The surface-emitting device according to any one of (1) to (21), wherein the laminated structure further includes: a plurality of the light-emitting layers stacked on one another; and a tunnel junction layer disposed between two adjacent light-emitting layers among the plurality of light-emitting layers. (23) The surface-emitting device according to any one of (1) to (22), wherein the laminated structure includes a layer disposed on the side of the light-emitting layer opposite to the reflection structure side, the layer having the emission surface. (24) The surface-emitting device according to (23), wherein the layer is a substrate or a reflecting mirror. (25) The surface-emitting device according to any one of (1) to (24), wherein the laminated structure further includes a reflecting mirror disposed between the light-emitting layer and the reflection structure. (26) The surface-emitting device according to any one of (1) to (25), wherein the laminated structure has a missing portion on the side of the light-emitting surface or on the opposite side to the light-emitting surface. (27) An electronic device comprising a surface-emitting device including a laminated structure including a light-emitting layer and a reflector stacked on each other, the laminated structure having a light-emitting surface on the opposite side to the reflector side of the light-emitting layer, and the reflector having a reflectance distribution in an in-plane direction.

[0267] 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220: surface-emitting device 103: light-emitting layer 105: oxide constriction layer 107: anode electrode (electrode) 108: reflection structure 108-1: first portion 108-2: second portion 108a: multilayer film reflector 108b: metal reflector 109: cathode electrode (electrode) 111: cathode wiring LS: laminated structure LA: light-emitting region IIA: ion-implanted region (current constriction region) 121: trench (defective portion) 1000: distance measurement device (electronic device) ES: emission surface

Claims

1. A surface-emitting device comprising a laminated structure including a light-emitting layer and a reflection structure stacked on top of each other, the laminated structure having an emission surface on the side of the light-emitting layer opposite to the reflection structure side, and the reflection structure having a reflectance distribution in an in-plane direction.

2. The surface light emitting device according to claim 1, wherein the reflective structure has first and second portions that differ in position and reflectivity in the in-plane direction.

3. The surface light emitting device according to claim 2, wherein the first portion corresponds to a light emitting region of the light emitting layer.

4. The surface emitting device according to claim 2, wherein the second portion surrounds the first portion.

5. The surface light emitting device according to claim 3, wherein the reflectance of the first portion is lower than the reflectance of the second portion.

6. The surface light emitting device according to claim 3, wherein the reflectance of the first portion is higher than the reflectance of the second portion.

7. The surface emitting device according to claim 2, wherein the reflection structure has a multilayer reflector in which a plurality of refractive index layers are stacked, the multilayer reflector being included in at least one of the first and second portions.

8. The surface light emitting device according to claim 7, wherein the multilayer film reflector is included in the first or second portion.

9. The surface light emitting device according to claim 7, wherein the multilayer film reflector is included in the first and second portions.

10. The surface light emitting device according to claim 9, wherein the reflectance of the multilayer reflector in the first portion is different from the reflectance of the multilayer reflector in the second portion.

11. The surface emitting device according to claim 10, wherein the number of refractive index layers of the multilayer reflector in the first portion is different from the number of refractive index layers of the multilayer reflector in the second portion.

12. The surface light emitting device according to claim 7, wherein the multilayer film reflector is a dielectric multilayer film reflector.

13. The surface emitting device according to claim 2, wherein the reflecting structure comprises a metallic reflector included in at least one of the first and second portions.

14. The surface light emitting device according to claim 13, wherein the metal reflector is included in the first portion or the second portion.

15. The surface emitting device according to claim 13, wherein the metal reflector is included in the first portion and the second portion.

16. The surface emitting device according to claim 15, wherein the reflectance of the metal reflector in the first portion is different from the reflectance of the metal reflector in the second portion.

17. The surface light emitting device according to claim 13, wherein the metal reflector also serves as an electrode and / or wiring.

18. The surface emitting device described in claim 2, wherein the reflection structure comprises: a multilayer film reflector having a plurality of stacked refractive index layers, the multilayer film reflector being included in at least one of the first and second portions; and a metal reflector being included in at least one of the first and second portions.

19. The surface light emitting device according to claim 2, further comprising a reflector arranged on the opposite side of the light emitting layer from the reflecting structure side, wherein the lower of the reflectivities of the first and second portions is lower than the reflectivity of the reflector.

20. The surface emitting device according to claim 2, further comprising a reflector arranged on the side of the light emitting layer opposite the reflective structure, wherein the reflector has the lowest reflectance among the reflectances of the first and second portions and the reflectance of the reflector.

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