Surface emitting laser

Abstract

Provided is a surface-emitting laser capable of achieving stability of a horizontal mode while suppressing a decrease in productivity. A surface emitting laser according to the present technology includes: a first structure including a substrate; and a second substrate disposed atop the first structure. The second structure includes a first reflector, a second reflector, an active layer disposed between the first reflector and the second reflector, and an optical confinement layer disposed between the active layer and a surface of the second reflector on a side opposite to the side of the active layer. The optical confinement layer has a high refractive index region and a low refractive index region surrounding the high refractive index region. The second structure and the high refractive index region each have a length direction and a width direction in plan view. Both the first ratio and the second ratio are greater than 1.00 and less than 2.00, the first ratio being a ratio of a length of the high refractive index region in the length direction to a length of the high refractive index region in the width direction, and the second ratio being a ratio of a length of the second structure in the length direction to a length of the second structure in the width direction. The first ratio is greater than the second ratio.

Description

Technical Field

[0001] A technology according to the present disclosure (hereinafter also referred to as “the present technology”) relates to a surface emitting laser. Background Art

[0002] Conventionally, a vertical cavity surface emitting laser (VCSEL) is known.

[0003] Among surface emitting lasers, there are surface emitting lasers in which a resonator having shape anisotropy is provided on a substrate to stabilize a width-directional mode (for example, see Patent Documents 1 and 2).

[0004] For example, in the surface emitting lasers described in Patent Documents 1 and 2, both the resonator and the aperture (high refractive index region) of the optical confinement layer included in the resonator have relatively large shape anisotropy.

[0005] Reference List

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2021-22679

[0008] Patent Document 2: Japanese Patent Application Publication No. 2019-212669 Summary of the invention

[0009] Problems to be solved by the present invention

[0010] However, in the surface emitting lasers described in Patent Documents 1 and 2, for example, there is room for improvement regarding stabilization of the width-direction mode while suppressing a decrease in productivity.

[0011] Therefore, a main object of the present technology is to provide a surface emitting laser capable of stabilizing a width-directional mode while suppressing a decrease in productivity.

[0012] Solution to the problem

[0013] The present technology provides a surface emitting laser, comprising:

[0014] A first structure includes a substrate; and

[0015] A second structure is disposed on the first structure, wherein

[0016] The second structure includes:

[0017] at least a portion of a first reflector;

[0018] a second reflector stacked with the first reflector;

[0019] an active layer disposed between the first reflector and the second reflector; and

[0020] an optical confinement layer arranged between a surface of the first reflector on a side opposite to the active layer and the active layer, and / or between a surface of the second reflector on a side opposite to the active layer and the active layer,

[0021] The optical confinement layer has a high refractive index region with a relatively high refractive index and a low refractive index region with a relatively low refractive index surrounding the high refractive index region,

[0022] Each of the second structure and the high refractive index region has a length direction and a width direction in a plan view,

[0023] The first ratio is a ratio of the length in the length direction of the high refractive index region to the length in the width direction, and the second ratio is a ratio of the length in the length direction of the second structure to the length in the width direction, both of which are greater than 1.00 and less than 2.00, and

[0024] The first ratio is greater than the second ratio.

[0025] The first ratio may be 1.75 or less.

[0026] The first ratio may be greater than 1.15.

[0027] The first ratio may be greater than or equal to 1.15 and less than or equal to 1.75.

[0028] The second ratio may be 1.50 or less.

[0029] The second ratio may be greater than 1.05.

[0030] The second ratio may be greater than or equal to 1.05 and less than or equal to 1.50.

[0031] The high refractive index region may have a symmetrical shape with respect to each of a length direction and a width direction of the high refractive index region in a plan view.

[0032] The second structure may have a symmetrical shape with respect to each of a length direction and a width direction of the second structure in a plan view.

[0033] The length direction or the width direction of the second structure may extend in a direction along the crystal direction <0 1 -1> of the substrate.

[0034] The area centroid of the second structure and the area centroid of the high refractive index region may not coincide with each other.

[0035] The first offset may be greater than the second offset, the first offset being the offset of the second structure and the high refractive index region in the length direction of the second structure, and the second offset being the offset of the second structure and the high refractive index region in the width direction of the second structure.

[0036] The first offset amount may be greater than or equal to 0.20 μm, and the second offset amount may be less than or equal to 0.10 μm.

[0037] The cross-section of the second structure may not have a straight portion and / or a top portion.

[0038] An angle formed by the second structure and the high refractive index region in the length direction in a plan view may be 10° or less.

[0039] A high resistance region surrounding the high refractive index region may be provided in the second structure and / or the first structure.

[0040] The inner edge of the high resistance region may have a length direction and a width direction in a plan view, and a ratio of a length of the inner edge in the length direction to a length in the width direction may be greater than 1.00 and less than 1.10.

[0041] A low dielectric constant region surrounding the second structure may also be included.

[0042] The low dielectric constant region may include a first portion having a circumferential shape surrounding the second structure and a second portion having a surrounding portion arranged on the second structure. The inner edge of the surrounding portion may have a length direction and a width direction in a plan view. The ratio of the length of the inner edge in the length direction to the length in the width direction may be greater than 1.00 and less than 1.10.

[0043] The optical confinement layer may be an oxidative shrink layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A and Figure 1 B are cross-sectional views (part 1 and part 2 ) of the surface emitting laser according to Example 1 of the first embodiment of the present technology, respectively.

[0045] Figure 2 is a plan view of a surface emitting laser according to Example 1 of the first embodiment of the present technology.

[0046] Figure 3 It is used to illustrate the use of manufacturing Figure 1 A to Figure 2 Flowchart of an embodiment of a method of a surface emitting laser in FIG.

[0047] Figure 4 A and Figure 4 B is used for manufacturing Figure 1 A to Figure 2A cross-sectional view (Part 1 and Part 2) of each process of an embodiment of a method of a surface emitting laser.

[0048] Figure 5 A and Figure 5 B is used for manufacturing Figure 1 A to Figure 2 A cross-sectional view (Part 1 and Part 2) of each process of an embodiment of a method of a surface emitting laser.

[0049] Figure 6 A and Figure 6 B is used for manufacturing Figure 1 A to Figure 2 A cross-sectional view (Part 1 and Part 2) of each process of an embodiment of a method of a surface emitting laser.

[0050] Figure 7 A and Figure 7 B is used for manufacturing Figure 1 A to Figure 2 A cross-sectional view (Part 1 and Part 2) of each process of an embodiment of a method of a surface emitting laser.

[0051] Figure 8 A and Figure 8 B is used for manufacturing Figure 1 A to Figure 2 A cross-sectional view (Part 1 and Part 2) of each process of an embodiment of a method of a surface emitting laser.

[0052] Fig. 9 A and Fig. 9 B is used for manufacturing Figure 1 A to Figure 2 A cross-sectional view (Part 1 and Part 2) of each process of an embodiment of a method of a surface emitting laser.

[0053] Fig.10 A and Fig.10 B is used for manufacturing Figure 1 A to Figure 2 A cross-sectional view (Part 1 and Part 2) of each process of an embodiment of a method of a surface emitting laser.

[0054] Fig.11 is a plan view of a surface emitting laser according to Example 2 of the first embodiment of the present technology.

[0055] Fig.12 is a plan view of a surface emitting laser according to Example 3 of the first embodiment of the present technology.

[0056] Fig.13 is a plan view of a surface emitting laser according to Example 4 of the first embodiment of the present technology.

[0057] Fig.14 is a plan view of a surface emitting laser according to Example 5 of the first embodiment of the present technology.

[0058] Fig.15 is a plan view of a surface emitting laser according to Example 6 of the first embodiment of the present technology.

[0059] Fig.16 is a plan view of a surface emitting laser according to Example 7 of the first embodiment of the present technology.

[0060] Fig.17 is a plan view of a surface emitting laser according to Example 8 of the first embodiment of the present technology.

[0061] Fig.18 is a plan view of a surface emitting laser according to Example 9 of the first embodiment of the present technology.

[0062] Fig.19 is a plan view of a surface emitting laser according to Example 10 of the first embodiment of the present technology.

[0063] Fig. 20 is a plan view of a surface emitting laser according to Example 11 of the first embodiment of the present technology.

[0064] Fig.21 is a cross-sectional view (part 1) of a surface emitting laser according to Example 1 of a second embodiment of the present technology.

[0065] Fig. 22 is a cross-sectional view (part 2) of the surface emitting laser according to Example 1 of the second embodiment of the present technology.

[0066] Fig.23 is a cross-sectional view (part 3) of the surface emitting laser according to Example 1 of the second embodiment of the present technology.

[0067] Fig.24 is a plan view of a surface emitting laser according to Example 1 of the second embodiment of the present technology.

[0068] Fig.25 It is used to explain the manufacturing Figure 21 to Figure 24 Flowchart of an embodiment of a method of a surface emitting laser in FIG.

[0069] Fig.26 A and Fig.26 B is used for manufacturing Figure 21 to Figure 24 A cross-sectional view of each process of an embodiment of a surface emitting laser method.

[0070] Fig. 27 A and Fig. 27 B is used for manufacturing Figure 21 to Figure 24 A cross-sectional view of each process of an embodiment of a surface emitting laser method.

[0071] Fig.28 A and Fig.28 B is used for manufacturing Figure 21 to Figure 24 A cross-sectional view of each process of an embodiment of a surface emitting laser method.

[0072] Fig.29 A and Fig.29 B is used for manufacturing Figure 21 to Figure 24 A cross-sectional view of each process of an embodiment of a surface emitting laser method.

[0073] Fig.30 A and Fig.30 B is used for manufacturing Figure 21 to Figure 24 A cross-sectional view of each process of an embodiment of a surface emitting laser method.

[0074] Fig.31 It is used to manufacture Figure 21 to Figure 24 A cross-sectional view of each process of an embodiment of a surface emitting laser method is shown in FIG.

[0075] Fig.32 A and Fig.32 B is used for manufacturing Figure 21 to Figure 24 A cross-sectional view (Part 1 and Part 2) of each process of an embodiment of a method of a surface emitting laser.

[0076] Fig.33 A and Fig.33 B is used for manufacturing Figure 21 to Figure 24 A cross-sectional view of each process of an embodiment of a surface emitting laser method.

[0077] Fig.34 A and Fig.34 B is used for manufacturing Figure 21 to Figure 24 A cross-sectional view of each process of an embodiment of a surface emitting laser method.

[0078] Fig.35 A and Fig.35 B is used for manufacturing Figure 21 to Figure 24 A cross-sectional view of each process of an embodiment of a surface emitting laser method.

[0079] Fig.36 is a plan view of a surface emitting laser according to Example 2 of the second embodiment of the present technology.

[0080] Fig.37 is a cross-sectional view (part 1) of a surface emitting laser according to Example 3 of the second embodiment of the present technology.

[0081] Fig.38 is a cross-sectional view (part 2) of a surface emitting laser according to Example 3 of the second embodiment of the present technology.

[0082] Fig.39 is a plan view of a surface emitting laser according to Example 3 of the second embodiment of the present technology.

[0083] Fig.40 A is a plan view of a surface emitting laser according to Example 4 of the second embodiment of the present technology. Fig.40 B is a bottom view of the surface emitting laser according to Example 4 of the second embodiment of the present technology.

[0084] Fig.41 A and Fig.41 B is a cross-sectional view (part 1 and part 2 ) of the surface emitting laser according to the first modification example of the first embodiment of the present technology.

[0085] Fig.42 A and Fig.42 B is a cross-sectional view (part 1 and part 2 ) of a surface emitting laser according to a second modification example of the first embodiment of the present technology.

[0086] Fig.43 A and Fig.43 B is a cross-sectional view (part 1 and part 2 ) of the surface emitting laser according to the third modification example of the first embodiment of the present technology.

[0087] Fig.44 A and Fig.44 B is a cross-sectional view (part 1 and part 2 ) of the surface emitting laser according to the fourth modification example of the first embodiment of the present technology.

[0088] Fig.45 A and Fig.45 B is a cross-sectional view (part 1 and part 2 ) of the surface emitting laser according to the fifth modification example of the first embodiment of the present technology.

[0089] Fig.46 A and Fig.46 B is a cross-sectional view (part 1 and part 2 ) of the surface emitting laser according to the sixth modification example of the first embodiment of the present technology.

[0090] Fig.47 A and Fig.47 B is a cross-sectional view (part 1 and part 2 ) of the surface emitting laser according to the seventh modification example of the first embodiment of the present technology.

[0091] Fig.48 A and Fig.48B is a cross-sectional view (part 1 and part 2 ) of the surface emitting laser according to the eighth modification example of the first embodiment of the present technology.

[0092] Fig.49 A and Fig.49 B is a cross-sectional view (part 1 and part 2 ) of a surface emitting laser array according to a ninth modification example of the first embodiment of the present technology.

[0093] Fig.50 is a plan view of a surface emitting laser array according to a ninth modification example of the first embodiment of the present technology.

[0094] Fig.51 is a cross-sectional view of a surface emitting laser according to a first modification example of the second embodiment of the present technology (part 1).

[0095] Fig.52 is a cross-sectional view of a surface emitting laser according to a first modification example of the second embodiment of the present technology (part 2).

[0096] Fig.53 is a plan view of a surface emitting laser according to a first modification example of the second embodiment of the present technology.

[0097] Fig.54 It is used to explain the manufacturing Figure 51 to Figure 53 Flowchart of an embodiment of a method of a surface emitting laser in FIG.

[0098] Fig.55 A and Fig.55 B is used for manufacturing Figure 51 to Figure 53 A cross-sectional view of each process of an embodiment of a surface emitting laser method.

[0099] Fig.56 A and Fig.56 B is used for manufacturing Figure 51 to Figure 53 A cross-sectional view of each process of an embodiment of a surface emitting laser method.

[0100] Fig.57 A and Fig.57 B is used for manufacturing Figure 51 to Figure 53 A cross-sectional view of each process of an embodiment of a surface emitting laser method.

[0101] Fig.58 It is used to manufacture Figure 51 to Figure 53 sectional views of each process of an embodiment of the method of surface emitting laser shown in FIG.

[0102] Fig.59 A and Fig.59 B is used for manufacturing Figure 51 to Figure 53 A cross-sectional view of each process of an embodiment of a surface emitting laser method.

[0103] Fig.60 A and Fig.60 B is used for manufacturing Figure 51 to Figure 53 A cross-sectional view of each process of an embodiment of a surface emitting laser method.

[0104] Fig.61 is a cross-sectional view of a surface emitting laser according to a second modification example of the second embodiment of the present technology (part 1).

[0105] Fig.62 is a cross-sectional view of a surface emitting laser according to a second modification example of the second embodiment of the present technology (part 2).

[0106] Fig.63 is a plan view of a surface emitting laser according to a second modification example of the second embodiment of the present technology.

[0107] Fig.64 is a plan view of a surface emitting laser according to a third modification example of the second embodiment of the present technology.

[0108] Fig.65 is a graph showing the relationship between the table rotation angle and RIN. DETAILED DESCRIPTION

[0109] Hereinafter, preferred embodiments of the present technology will be described in detail with reference to the accompanying drawings. Note that in this specification and the accompanying drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant descriptions are omitted. The embodiments described below illustrate representative embodiments of the present technology, and the scope of the present technology is not narrowly interpreted by these embodiments. In this specification, even in the case where a surface emitting laser according to the present technology is described to exhibit multiple effects, it is sufficient if the surface emitting laser according to the present technology exhibits at least one effect. The effects described in this specification are merely embodiments and are not limited, and other effects may be applied.

[0110] Furthermore, the description will be made in the following order.

[0111] 0. Introduction

[0112] 1. Surface-Emitting Laser According to Example 1 of First Embodiment of the Present Technology

[0113] 2. Surface Emitting Laser According to Example 2 of First Embodiment of the Present Technology

[0114] 3. Surface-Emitting Laser According to Example 3 of First Embodiment of the Present Technology

[0115] 4. Surface Emitting Laser According to Example 4 of First Embodiment of the Present Technology

[0116] 5. Surface Emitting Laser According to Example 5 of First Embodiment of the Present Technology

[0117] 6. Surface Emitting Laser According to Example 6 of First Embodiment of the Present Technology

[0118] 7. Surface-Emitting Laser According to Example 7 of First Embodiment of the Present Technology

[0119] 8. Surface-Emitting Laser According to Example 8 of First Embodiment of the Present Technology

[0120] 9. Surface-Emitting Laser According to Example 9 of First Embodiment of the Present Technology

[0121] 10. Surface-emitting laser according to Example 10 of first embodiment of the present technology

[0122] 11. Surface emitting laser according to Example 11 of first embodiment of the present technology

[0123] 12. Surface emitting laser according to Example 1 of second embodiment of the present technology

[0124] 13. Surface emitting laser according to Example 2 of second embodiment of the present technology

[0125] 14. Surface emitting laser according to Example 3 of second embodiment of the present technology

[0126] 15. Surface emitting laser according to Example 4 of second embodiment of the present technology

[0127] 16. Modifications to this Technology

[0128] <0. Introduction>

[0129] Conventionally, for example, there is known a surface emitting laser in which a plurality of components including a first multilayer film reflector, an active layer, an oxidized shrinkage layer for setting a current injection region (light emitting region) of the active layer, and a second multilayer film reflector for generating optical resonance with the first multilayer film reflector are stacked on a substrate.

[0130] In the surface emitting laser, a multilayer body in which a first multilayer film reflector, an active layer, an oxide layer as a material of an oxide shrink layer, and a second multilayer film reflector are stacked on a substrate is etched to form a mesa exposing a side surface of the oxide layer, and the oxide layer is partially oxidized from the periphery of the mesa to form an oxide shrink layer surrounding an unoxidized region in an oxidized region. In the surface emitting laser, a current is injected into a current injection region provided in the oxide shrink layer via an electrode so that the active layer emits light by current excitation, and laser oscillation occurs in a resonator including the first multilayer film reflector, the second multilayer film reflector, and the active layer.

[0131] In such a surface emitting laser, in the process of oxidizing the oxide layer as a material, as the refractive index decreases, the oxidized region in the peripheral portion becomes a region having a refractive index lower than that of the unoxidized region in the central portion in the oxidized shrinkage layer. The width-direction distribution of the refractive index has a structure in which light is confined in a region having a high refractive index in the central portion of the mesa, and high optical confinement of the active layer is achieved three-dimensionally together with a resonator that confines light in the length direction. For this reason, oscillations in various width-direction modes occur, but since the fluctuation of the width-direction mode greatly involves the transmission characteristics, the stabilization of the width-direction mode is emphasized in the surface emitting laser.

[0132] In order to stabilize the width direction mode, conventionally, for example, as disclosed in Patent Document 1, the mesa shape is formed into an elliptical shape (the mesa cross-sectional shape has a major axis and a minor axis orthogonal to each other, and the ratio of the lengths of the major axis and the minor axis is twice or more) with extreme shape anisotropy, or as disclosed in Patent Document 2, the mesa cross-sectional shape is formed into a semi-cylindrical shape with extreme anisotropy, so that the refractive index distribution used for optical confinement has anisotropy to stabilize the width direction mode.

[0133] However, since a surface emitting laser having a mesa having such extreme shape anisotropy causes a large asymmetry phenomenon in its manufacturing process, characteristic variations increase due to height variations around the mesa, film thickness variations of layers constituting the mesa, etc. As a result, reliability decreases, and thus productivity (yield) decreases.

[0134] Therefore, after intensive studies, the inventors developed a surface emitting laser according to the present technology as a surface emitting laser capable of stabilizing a width-directional mode while suppressing a decrease in productivity.

[0135] Hereinafter, some embodiments of the surface emitting laser according to the present technology will be described. Figure 1 The upper portion in the cross-sectional view of the like will be described as the upper side, and Figure 1 The lower portion in the cross-sectional view of FIG. 1 will be described as the lower side.

[0136] <1. Surface-Emitting Laser According to Example 1 of First Embodiment of the Present Technology>

[0137] Figure 1 A and Figure 1 B are cross-sectional views (part 1 and part 2 ) of the surface emitting laser 10 - 1 according to Example 1 of the first embodiment of the present technology, respectively. Figure 2 is a plan view of the surface emitting laser 10 - 1 . Figure 1 A is along Figure 2 A cross-sectional view taken along line 1A-1A in FIG. Figure 1 B is along Figure 2 A cross-sectional view taken along line 1B-1B in FIG.

[0138] <<Configuration of surface emitting laser>>

[0139] (Overall structure)

[0140] The surface emitting laser 10 - 1 of Example 1 according to the first embodiment of the present technology is a vertical cavity surface emitting laser (VCSEL) The surface emitting laser 10 - 1 is driven by, for example, a laser driver.

[0141] As an example, Figure 1 A. Figure 1 B and Figure 2 As shown in FIG. 1 , the surface emitting laser 10-1 includes a first structure ST1 including a substrate 101 and a second structure ST2 disposed (stacked) on the first structure ST1. Hereinafter, the direction (vertical direction) in which the first structure ST1 and the second structure ST2 are stacked is also referred to as a "stacking direction".

[0142] As an embodiment, the first structure ST1 includes a substrate 101. As an embodiment, the second structure ST2 is a mesa structure provided on the substrate 101. Note that the first structure ST1 may have a buffer layer on the substrate 101.

[0143] The second structure ST2 includes a first reflector 102, a second reflector 107 stacked with the first reflector 102, an active layer 104 disposed between the first reflector 102 and the second reflector 107, and an oxidized shrinkage layer 106 as an optical confinement layer disposed between a surface of the second reflector 107 on a side opposite to a side of the active layer 104 and the active layer 104. As an embodiment, the oxidized shrinkage layer 106 is disposed inside the second reflector 107.

[0144] That is, the surface emitting laser 10 - 1 includes a resonator in which the active layer 104 is sandwiched between the first reflector 102 and the second reflector 107 which are stacked on each other.

[0145] For example, the second structure ST2 also includes a first cladding layer 103 disposed between the first reflector 102 and the active layer 104, a second cladding layer 105 disposed between the active layer 104 and the second reflector 107, and a contact layer 111 disposed on the second reflector 107. An annular (ring-shaped) anode electrode 108 is disposed on the contact layer 111. The cathode electrode 109 is disposed in the peripheral region of the second structure ST2 on the upper surface (surface on the second structure ST2 side) of the substrate 101. Note that a highly doped semiconductor layer (e.g., a highly doped n-GaAs layer) may be disposed as a contact layer between the substrate 101 and the cathode electrode 109.

[0146] Each of the substrate 101, the second structure ST2, the anode electrode 108, and the cathode electrode 109 is at least partially covered by the insulating film 110. A contact hole CH1 for exposing the anode electrode 108 is provided in a portion of the insulating film 110 corresponding to the anode electrode 108. In a portion of the insulating film 110 corresponding to the cathode electrode 109, a contact hole CH2 for exposing the cathode electrode 109 is provided.

[0147] (Substrate)

[0148] For example, the substrate 101 includes a conductive GaAs substrate (n-GaAs substrate).

[0149] (First reflector)

[0150] The first reflector 102 is, for example, a semiconductor multilayer film reflector. The multilayer film reflector is also called a distributed Bragg reflector (DBR). The first reflector 102 is a semiconductor multilayer film reflector (a semiconductor layer film reflector including an impurity semiconductor) of a first conductivity type (e.g., n-type). For example, the first reflector 102 includes a compound semiconductor (GaAs-based compound semiconductor) lattice-matched to GaAs. More specifically, as an embodiment, the first reflector 102 has a stacked structure in which a high refractive index layer (e.g., n-GaAs) and a low refractive index layer (e.g., n-AlGaAs) are alternately stacked. The optical thickness of each refractive index layer is 1 / 4 of the oscillation wavelength λ of the surface emitting laser 10-1.

[0151] (First coating layer)

[0152] For example, the first cladding layer 103 includes a GaAs-based compound semiconductor (eg, n-AlGaAs) of a first conductivity type (eg, n-type). The "cladding layer" is also referred to as a "spacer layer".

[0153] (Active layer)

[0154] For example, the active layer 104 has a quantum well structure including a barrier layer (the barrier layer includes a GaAs-based compound semiconductor (e.g., InGaAs)) and a quantum well layer designed to have an emission wavelength of 780 nm to 950 nm. The quantum well structure may be a single quantum well structure (QW structure) or a multiple quantum well structure (MQW structure). Note that the active layer 104 may have a plurality of QW structures or a plurality of MQW structures stacked via a tunnel junction. In the active layer 104, a region (e.g., a central region) corresponding to a high refractive index region 106a of the oxidized shrinkage layer 106 to be described later is a light emitting region LA (current injection region). The active layer 104 is preferably arranged at or near the position of the antinode of the standing wave generated in the resonator (a position where the light intensity is high).

[0155] (Second coating layer)

[0156] The second cladding layer 105 is formed of a GaAs-based compound semiconductor (eg, p-AlGaAs) of a second conductivity type (eg, p-type). The "cladding layer" is also referred to as a "spacer layer".

[0157] (Second reflector)

[0158] The second reflector 107 is, for example, a semiconductor stacked film reflector. The second reflector 107 is a semiconductor multilayer film reflector (a semiconductor layer-layer film reflector including an impurity semiconductor) of a second conductivity type (e.g., p-type). For example, the second reflector 107 includes a compound semiconductor (GaAs-based compound semiconductor) lattice-matched to GaAs. The second reflector 107 has a stacked structure in which a high refractive index layer (e.g., p-GaAs) and a low refractive index layer (e.g., p-AlGaAs) are alternately stacked. The optical thickness of each refractive index layer is, for example, 1 / 4 of the oscillation wavelength λ. The reflectivity of the second reflector 107 is set to be slightly lower than the reflectivity of the first reflector 102. That is, as an embodiment, the surface emitting laser 10-1 is a surface emitting laser of a front surface emitting type that emits laser light toward the front surface (upper surface) of the substrate 101. Note that by setting the reflectivity of the second reflector 107 to be slightly higher than the reflectivity of the first reflector 102, a surface emitting laser of a back-emitting type that emits laser light to the back (lower surface) side of the substrate 101 can also be configured.

[0159] (Optical confinement layer)

[0160] The oxidized shrinkage layer 106 as an optical confinement layer has a high refractive index region 106a and a low refractive index region 106b, wherein the high refractive index region 106a has a relatively high refractive index, and the low refractive index region 106b surrounds the high refractive index region 106a and has a relatively low refractive index. The high refractive index region 106a is, for example, a non-oxidized region (e.g., an AlAs layer or an AlGaAs layer). The low refractive index region 106b is, for example, an oxidized region (e.g., an AlAs layer or an AlGaAs layer). x O y The oxidized shrinkage layer 106 also serves as a current limiting layer (current limiting layer) for setting the light emitting region (current injection region) of the active layer 104, since the oxidized region as the low refractive index region 106b has a higher resistance than the unoxidized region as the high refractive index region 106a. That is, the unoxidized region as the high refractive index region 106a is also a low resistance region with a relatively low resistance, and the oxidized region as the low refractive index region 106b is also a high resistance region with a relatively high resistance. The oxidized shrinkage layer 106 is preferably arranged at or near the position of the node of the standing wave generated in the resonator (a position with low light intensity).

[0161] (Contact layer)

[0162] The contact layer 111 has a function of easily injecting the current flowing into the second structure ST2 into the active layer 104 through the anode 108 (current injection efficiency improvement function). The contact layer 111 is also called a "current injection layer". The contact layer 111 is a highly doped layer (a low resistance layer with high carrier conductivity), which is a compound semiconductor layer highly doped with impurities. Here, the contact layer 111 includes p-GaAs doped with p-type impurities (e.g., C) at a high concentration.

[0163] (Insulation film)

[0164] The insulating film 110 is a protective film (passivation film) containing a dielectric such as SiO 2 , SiN, or SiON.

[0165] (anode)

[0166] The anode 108 is arranged in a ring shape (annular shape) on the second structure ST2 (specifically, on the contact layer 111) so as to surround the light emitting area LA of the active layer 104 in a plan view (hereinafter, also referred to as "viewed from the layering direction"). For example, the anode electrode 108 has a stacked structure of AuGe / Ni / Au. In the stacked structure, as an embodiment, AuGe, Ni and Au have film thicknesses of 150nm, 50nm and 200nm, respectively. Note that the anode electrode 108 may have a single-layer structure. Here, the inner diameter of the anode electrode 108 is set to 12.6μm, and the outer diameter is set to 18.0μm. The inner diameter side of the anode electrode 108 is the emission port. A portion of the anode electrode 108 exposed through the contact hole CH1 is connected to the anode side of the laser driver.

[0167] (cathode)

[0168] For example, the cathode electrode 109 is provided on the substrate 101 in a substantially circular shape when viewed from above. The cathode electrode 109 has a stacked structure of Ti / Pt / Au. In the stacked structure, as an embodiment, Ti, Pt, and Au have film thicknesses of 50 nm, 100 nm, and 200 nm, respectively. Note that the cathode electrode 109 may have a single-layer structure. A portion of the cathode electrode 109 exposed through the contact hole CH2 is connected to the cathode side of the laser driver.

[0169] (Details of the second structure and optical confinement layer)

[0170] like Figure 1 A. Figure 1 B and Figure 2 As shown, in a plan view, each of the second structure ST2 and the high refractive index region 106a of the oxidized shrinkage layer 106 has a length direction and a width direction. That is, in a plan view, both the second structure ST2 and the high refractive index region 106a have shape anisotropy (asymmetry).

[0171] The second structure ST2 has a symmetrical shape (e.g., a closed curve shape) with respect to each of the length direction and the width direction of the second structure ST2 in a plan view. In this case, since the second structure ST2 has extremely low shape unevenness (asymmetry) in each of the length direction and the width direction, height variation around the mesa during the manufacturing process, film thickness variation on the mesa side surface of the insulating film 110, and the like can be suppressed.

[0172] In a plan view, the high refractive index region 106a has a symmetrical shape (eg, a closed curve shape) with respect to each of the length direction and the width direction of the high refractive index region 106a. Such an axisymmetric shape resists shape changes due to a manufacturing process and enables stable manufacturing.

[0173] More specifically, each of the second structure ST2 and the high refractive index region 106a has an elliptical shape in a plan view. More specifically, the second structure ST2 has an elliptical columnar shape and has a major axis and a minor axis. The high refractive index region 106a has an elliptical plate shape and has a major axis and a minor axis.

[0174] The second structure ST2 and the high refractive index region 106a both have relatively small shape anisotropy (asymmetry). Specifically, the first ratio r1 (ie, the length D in the length direction Ld1 of the high refractive index region 106a) L1 The length D in the width direction Sd1 S1 The ratio D L1 / D S1 ) and a second ratio r2 (ie, the length D of the second structure ST2 in the length direction Ld2) L2 The length D in the width direction Sd2 S2 The ratio D L2 / D S2 ) are both greater than 1.00 and less than 2.00. The high refractive index region 106a has a greater shape anisotropy than the second structure ST2. Specifically, the first ratio r1 is greater than the second ratio r2.

[0175] Here, the area centroid C1 of the high refractive index region 106a and the area centroid C2 of the second structure ST2 are consistent with each other. In a plan view, the area centroids C1 and C2 coincide with the center of the anode electrode 108. Here, in a plan view, the second structure ST2 and the high refractive index region 106a have the same length direction (long axis direction) and the same width direction (short axis direction).

[0176] Generally, in the oxidation process for forming the oxidation shrinkage layer on the (100) substrate, since the oxidation layer as a material is oxidized at a substantially uniform oxidation rate (oxidation rate) from all directions, that is, there is no anisotropy of the oxidation rate, the first ratio r1 increases as the second ratio r2 increases. Conversely, there is a premise that the second ratio r2 increases as the first ratio r1 increases.

[0177] The inventors have found that the greater the shape anisotropy (specifically, the first ratio r1 and the second ratio r2) of the second structure ST2 and the high refractive index region 106a, the more the width direction mode can be stabilized, but since the asymmetric phenomenon occurs to a large extent in the manufacturing process, the characteristic change caused by the height change around the mesa structure as the second structure ST2, the film thickness change of the layer constituting the mesa structure, etc. become larger, resulting in the degradation of productivity (yield). That is, the inventors have found that there is a trade-off relationship between the stabilization of the width direction mode and the suppression of the reduction in productivity related to the size of the shape anisotropy (asymmetry). Based on this new discovery, the inventors have deeply studied the strength of the shape anisotropy of the second structure ST2 and the high refractive index region 106a, and have concluded that when at least one of the first ratio r1 and the second ratio r2 is 2.00 or more, it is difficult to significantly suppress the reduction in productivity.

[0178] The present inventors have gained such confidence that, as described above, by setting both the first ratio r1 and the second ratio r2 to be greater than 1.00 and less than 2.00, it is possible to stabilize the width direction mode while suppressing a decrease in productivity. In addition, the inventors have deeply studied the magnitude relationship between the shape anisotropy of the second structure ST2 and the shape anisotropy of the high refractive index region 106a, and as described above, by making the first ratio r1 greater than the second ratio r2, the shape anisotropy (asymmetry) of the high refractive index region 106a can be relatively increased while the shape anisotropy (asymmetry) of the second structure ST2 can be relatively reduced, and the inventors have succeeded in stabilizing the width direction mode (achieving stabilization of the width direction mode and suppression of a decrease in productivity) while suppressing a decrease in productivity (yield).

[0179] (About the first ratio)

[0180] The first ratio r1 is preferably 1.75 or less, and more preferably 1.50 or less. When the first ratio r1 is small, the second ratio r2 is also small, and suppression of a decrease in productivity can be promoted.

[0181] The first ratio r1 is preferably 1.15 or more, and more preferably 1.25 or more. When the first ratio r1 is large, the width direction mode stabilization can be promoted.

[0182] The first ratio r1 is preferably 1.15 or more and 1.75 or less. Therefore, this makes it possible to achieve a high level of width direction mode stabilization and suppression of productivity reduction.

[0183] The first ratio r1 may be 1.15 or more and 1.50 or less in order to achieve both width direction pattern stability and suppression of productivity reduction at a high level while focusing on suppression of productivity reduction.

[0184] The first ratio r1 may be 1.25 or more and 1.75 or less in order to achieve width direction mode stabilization and suppression of productivity reduction at a high level while focusing on width direction mode stabilization.

[0185] The first ratio r1 is preferably 1.25 or more and 1.50 or less. Therefore, this makes it possible to achieve width direction mode stabilization and suppression of productivity reduction at a higher level.

[0186] Here, as an example, the major axis length and the minor axis length of the high refractive index region 106a are set to 8.5 μm and 6.5 μm, respectively, and the first ratio r1 is 1.31. Note that, in consideration of the change in oxidation rate when the oxidative shrinkage layer 106 is formed, any of the major axis length and the minor axis length of the high refractive index region 106a may be set to an appropriate value as long as the error from the set value is within the range of ±0.50 μm.

[0187] (About the second ratio)

[0188] The second ratio r2 is preferably 1.75 or less, and more preferably 1.50 or less. When the second ratio r2 is small, suppression of a decrease in productivity can be promoted.

[0189] The second ratio r2 is preferably 1.05 or more, and more preferably 1.08 or more. When the second ratio r2 is larger, the first ratio r1 is also larger, and the width direction mode stabilization can be promoted.

[0190] The second ratio r2 is preferably 1.05 or more and 1.75 or less. Therefore, this makes it possible to achieve a high level of width direction mode stabilization and suppression of productivity reduction.

[0191] The second ratio r2 may be 1.05 or more and 1.50 or less in order to achieve both width direction pattern stability and suppression of productivity reduction at a high level while focusing on suppression of productivity reduction.

[0192] The second ratio r2 may be 1.08 or more and 1.75 or less in order to achieve width direction mode stabilization and suppression of productivity reduction at a high level while focusing on width direction mode stabilization.

[0193] The second ratio r2 is preferably 1.08 or more and 1.50 or less. Therefore, this makes it possible to achieve width direction mode stabilization and suppression of productivity reduction at a higher level.

[0194] Here, as an example, the length of the major axis of the second structure ST2 is set to 22 μm, the length of the minor axis is set to 20 μm, and the second ratio r1 is 1.10.

[0195] (Regarding the shape of the cross section of the second structure)

[0196] The cross section (cross section perpendicular to the stacking direction) of the second structure ST2 has an elliptical shape and does not have a straight portion and a top. Therefore, the film thickness uniformity and step coverage of the insulating film 110 as a protective film covering the mesa structure as the second structure ST2 are excellent, and defects (no coverage and cracks) of the insulating film 110 can be suppressed. As a result, it is possible to suppress a decrease in reliability, and ultimately it is possible to promote suppression of a decrease in productivity.

[0197] <<Operation of Surface Emitting Laser>>

[0198] Hereinafter, the operation of the surface emitting laser 10-1 will be described briefly. In the surface emitting laser 10-1, for example, the current supplied from the anode side of the laser driver and flowing in from the anode electrode 108 is injected into the light emitting area LA (current injection area) which is the central area of ​​the active layer 104 via the contact layer 111, the second reflector 107 in which the oxidation shrinkage layer 106 is provided, and the second cladding layer 105 in this order (narrowed in the oxidation shrinkage layer 106). At this time, the active layer 104 emits light, the light is confined between the first reflector 102 and the second reflector 107 by the oxidation shrinkage layer 106 and reciprocates while being amplified by the active layer 104, and when the oscillation condition is satisfied, the light is emitted as laser light from the emission port on the inner diameter side of the anode electrode 108. Due to the influence of the asymmetry of the oxidation shrinkage layer 106, the laser light is in a stable width direction mode. The current passing through the active layer 104 reaches the cathode electrode 109 through the first cladding layer 103 , the first reflector 102 , and the substrate 101 in sequence, and flows out from the cathode electrode 109 to, for example, the cathode side of the laser driver.

[0199] <<Method for manufacturing a surface emitting laser>>

[0200] In the following, reference will be made to Figure 3 Flowchart and Figure 4 A to Fig.10 B is a cross-sectional view describing a method for manufacturing the surface emitting laser 10 - 1 . Figure 4 A. Figure 5 A. Figure 6 A. Figure 7 A. Figure 8 A. Fig. 9 A and Fig.10 A all correspond to the Figure 2 A cross-sectional view of a section taken along line 1A-1A in FIG. Figure 4 B. Figure 5 B. Figure 6 B. Figure 7 B. Figure 8 B. Fig. 9 B and Fig.10 B corresponds to the Figure 2 All cross-sectional views of the section taken along line 1B-1B in FIG.

[0201] Here, as an embodiment, by a semiconductor manufacturing method using a semiconductor manufacturing apparatus, a plurality of surface emitting lasers 10-1 are simultaneously generated on one wafer (hereinafter, for convenience, also referred to as "substrate 101") as a base material of a substrate 101. Next, a plurality of continuous and integrated surface emitting lasers 10-1 are separated from each other to obtain a plurality of chip-shaped surface emitting lasers 10-1.

[0202] In a first step S1, a multilayer body is generated (see Figure 4 A and Figure 4 B). Specifically, for example, the first reflector 102, the first cladding layer 103, the active layer 104, the second cladding layer 105, the second reflector 107, the second reflector 107 having the oxide layer 106S (for example, an AlAs layer or an AlGaAs layer as a material of the oxide shrinkage layer 106 is provided, and the contact layer 111 is stacked in this order (for example, by a metal organic chemical vapor deposition (MOCVD) method on a substrate 101 (for example, an n-GaAs substrate) as a growth substrate at a growth temperature of 605°C). It should be noted that when MOCVD is performed, for example, trimethylgallium ((CH3)3Ga) is used as a source gas for gallium, for example, trimethylaluminum ((CH3)3Al) is used as a source gas for aluminum, for example, trimethylindium ((CH3)3In) is used as a source gas for indium, and for example, trimethylarsenic (((CH3)3As) is used as a source gas for As. In addition, as a raw material gas for silicon, for example, monosilane (SiH4) is used, and as a raw material gas for carbon, for example, carbon tetrabromide (CBr4) is used.

[0203] In the next step S2, a mesa to be the second structure ST2 is formed. Specifically, first, a resist pattern RP having an elliptical shape in a plan view is formed by photolithography to cover a portion of the second structure ST2 to be formed on the front surface (upper surface) of the multilayer body on the second reflector 107 side (see FIG. Figure 5 A and Figure 5 B). Next, using the resist pattern RP as a mask, the multilayer body is etched by inductively coupled plasma (ICP) dry etching using, for example, Cl2, SiCl4, or Ar until the substrate 101 is exposed, and a mesa having an elliptical shape (for example, an ellipse with a major axis length of 22 μm and a minor axis length of 20 μm) in a plan view is formed on the substrate 101. Figure 6 A and Figure 6 B) Thereafter, the resist pattern RP is removed.

[0204] In the next step S3, an oxidized shrink layer 106 is formed as an optical confinement layer (see Figure 7 A and Figure 7 B). Specifically, the terrace having an elliptical shape in a plan view formed in step S2 is exposed to a high-temperature water vapor atmosphere, and the oxide layer 106S having a large Al composition is oxidized by a predetermined distance (for example, 6.75 μm) from the outer peripheral side toward the center side. As a result, an oxidized shrinkage layer 106 is formed in which an unoxidized region having an elliptical shape in a plan view (for example, an ellipse having a major axis length of 8.5 μm and a minor axis length of 6.5 μm) is surrounded by an oxidized region as a low refractive index region 106b.

[0205] In the next step S4, the anode electrode 108 and the cathode electrode 109 are formed (see Figure 8 A and Figure 8 B). Specifically, for example, using a lift-off method, the anode electrode 108 is formed in a ring shape (for example, the inner diameter is 12.6 μm and the outer diameter is 18.0 μm) on the top of the mesa (specifically, on the contact layer 111) so as to surround the high refractive index region 106a in a plan view, and the cathode electrode 109 is formed in a solid shape on the area around the mesa of the substrate 101. At this time, for example, vacuum deposition, sputtering, etc. are used to form the electrode materials of the anode electrode 108 and the cathode electrode 109.

[0206] In the next step S5, an insulating film 110 (see Fig. 9 A and Fig. 9 B).

[0207] In the final step S6, contact holes CH1 and CH2 are formed (see Fig.10 A and Fig.10 B) Specifically, by photolithography and etching, the insulating film 110 covering the upper surface of the anode electrode 108 is removed to form the contact hole CH1, and the insulating film 110 covering the upper surface of the cathode electrode 109 is removed to form the contact hole CH2.

[0208] <<Effects of Surface Emitting Lasers>>

[0209] Hereinafter, the effect of the surface emitting laser 10-1 will be described. The surface emitting laser 10-1 includes a first structure ST1 including a substrate 101 and a second structure ST2 disposed on the first structure ST1. The second structure ST2 includes a first reflector 102, a second reflector 107 stacked with the first reflector 102, an active layer 104 disposed between the first reflector 102 and the second reflector 107, and an oxidized shrinkage layer 106 as an optical confinement layer disposed between a surface on the side opposite to one side of the active layer 104 of the second reflector 107 and the active layer 104 (for example, in the second reflector 107). The oxidized shrinkage layer 106 as an optical confinement layer has a high refractive index region 106a and a low refractive index region 106b, the high refractive index region 106a having a relatively high refractive index, and the low refractive index region 106b surrounding the high refractive index region 106a and having a relatively low refractive index. In a plan view, each of the second structure ST2 and the high refractive index region 106a has a length direction and a width direction, and a first ratio r1, which is a ratio of the length in the length direction of the high refractive index region 106a to the length in the width direction, and a second ratio r2, which is a ratio of the length in the length direction of the second structure ST2 to the length in the width direction, are both greater than 1.00 and less than 2.00, and the first ratio r1 is greater than the second ratio r2.

[0210] In the surface emitting laser 10 - 1 , since the first ratio r1 and the second ratio r2 are greater than 1.00 and less than 2.00, and the first ratio r1 is greater than the second ratio r2 , width direction mode stabilization and suppression of productivity reduction can be achieved.

[0211] As a result, according to the surface emitting laser 10 - 1 , it is possible to stabilize the width direction mode while suppressing a decrease in productivity.

[0212] Hereinafter, some embodiments of a surface emitting laser according to the present technology will be described.

[0213] <2. Surface-Emitting Laser According to Example 2 of First Embodiment of the Present Technology>

[0214] Fig.11 1 is a plan view of a surface emitting laser 10-2 according to Example 2 of the first embodiment of the present technology. Fig.11 As shown, the surface emitting laser 10-2 has a configuration similar to that of the surface emitting laser 10-1 according to Embodiment 1, but the length direction Ld1 of the high refractive index region 106a and the length direction Ld2 of the second structure ST2 form an angle φ (0<φ≤10°), and the second structure ST2 has an elliptical shape that is slightly deformed in a plan view.

[0215] The surface emitting laser 10-2 can be manufactured by a manufacturing method substantially similar to the method for manufacturing the surface emitting laser 10-1 according to Embodiment 1. At this time, for example, the second structure ST2 is processed into an elliptical shape slightly distorted in the length direction Ld2 and / or the width direction Sd2 in a plan view, and an oxidation treatment is performed so that Ld1 and Ld2 can form an angle φ. Therefore, the length of the high refractive index region 106a in the length direction Ld2 of the second structure ST2 and the length of the high refractive index region 106a in the width direction Sd2 of the second structure ST2 can be adjusted, and the size of the asymmetry of the high refractive index region 106a relative to the second structure ST2 can be adjusted. Therefore, the degree of stability of the width direction mode can be adjusted.

[0216] <3. Surface-Emitting Laser According to Example 3 of First Embodiment of the Present Technology>

[0217] Fig.12 1 is a plan view of a surface emitting laser 10-3 according to Example 3 of the first embodiment of the present technology. Fig.12 As shown, the surface emitting laser 10-3 has a configuration similar to that of the surface emitting laser 10-1 according to Embodiment 1, except that the area centroid C1 of the high refractive index region 106a does not coincide with the area centroid C2 of the second structure ST2.

[0218] The surface emitting laser 10-3 can be manufactured by a manufacturing method that is substantially similar to the method for manufacturing the surface emitting laser 10-1 according to Embodiment 1. At this time, for example, an inclined substrate is used as the substrate 101, and anisotropy is imparted to the oxidation rate in the oxidation treatment for forming the oxidation shrinkage layer 106, whereby the area centroids C1 and C2 can be offset. At this time, preferably, the offset amount δ1 of the area centroid C1 in the length direction Ld2 of the second structure ST2 relative to the area centroid C2 is greater than the offset amount δ2 of the area centroid C1 in the width direction Sd2 of the second structure ST2 relative to the area centroid C2. Therefore, the asymmetry of the refractive index distribution of the low refractive index region 106b in the long side direction Ld2 can be relatively increased, and the stabilization of the width direction mode can be promoted.

[0219] δ1 is preferably 0.20 μm or more, more preferably 0.40 μm or more, and still more preferably 0.80 μm or more. δ2 is preferably less than 0.20 μm, more preferably 0.10 μm or less, and still more preferably 0.050 μm or less. For example, δ2 may be 0.

[0220] <4. Surface-Emitting Laser According to Example 4 of First Embodiment of the Present Technology>

[0221] Fig.131 is a plan view of a surface emitting laser 10-4 according to Example 4 of the first embodiment of the present technology. Fig.13 As shown, the surface emitting laser 10-4 has a configuration similar to that of the surface emitting laser 10-1 according to Example 1, but the length direction Ld1 of the high refractive index region 106a and the length direction Ld2 of the second structure ST2 form an angle φ (0<φ≤10°), and the area centroid C1 of the high refractive index region 106a and the area centroid C2 of the second structure ST2 are inconsistent with each other.

[0222] The surface emitting laser 10-4 has the features of the surface emitting lasers 10-2 and 10-3 according to Embodiments 2 and 3, and two effects can be obtained. The surface emitting laser 10-4 can be manufactured by a manufacturing method substantially similar to the method for manufacturing the surface emitting laser 10-1 according to Embodiment 1. At that time, it is preferable to use a method combining the feature points of the methods for manufacturing the surface emitting lasers 10-2 and 10-3 according to Embodiments 2 and 3.

[0223] Preferably, δ1 and δ2 of the surface emitting laser 10 - 4 also fall within a numerical range similar to those of δ1 and δ2 of the surface emitting laser 10 - 3 according to Embodiment 3. In this case, δ2 may be zero.

[0224] <5. Surface-Emitting Laser According to Example 5 of First Embodiment of the Present Technology>

[0225] Fig.14 1 is a plan view of a surface emitting laser 10-5 according to Example 5 of the first embodiment of the present technology. Fig.14 As shown, the surface emitting laser 10-5 has a configuration similar to that of the surface emitting laser 10-1 according to Example 1, but, in a plan view, the high refractive index region 106a has a quadrilateral shape (e.g., a modified rhombus shape) that is symmetrical in the length direction and asymmetrical in the width direction in the plan view, and the area centroid C1 of the high refractive index region 106a and the area centroid C2 of the second structure ST2 do not coincide with each other.

[0226] In the surface emitting laser 10-5, the cross section of the second structure ST2 has a modified rhombus shape in which the rhombus is distorted in the length direction, having a straight portion and a top portion. Therefore, the surface emitting laser 10-5 is inferior to the surface emitting laser 10-1 according to Embodiment 1 in terms of film thickness uniformity and step coverage.

[0227] In the surface emitting laser 10-5, the length direction of the second structure ST2 and the high refractive index region 106a coincide with each other, and the width direction does not coincide with each other. The displacement amount δ1 of the area centroid of the second structure ST2 and the high refractive index region 106a in the length direction is, for example, 0.20 μm.

[0228] In the surface emitting laser 10-5, the substrate 101 is an inclined substrate whose substrate plane orientation is a plane orientation inclined toward the crystal plane (100) or the crystal plane (0-1-1), and the side direction Sd2 of the mesa structure as the second structure ST2 extends in the direction along the crystal direction <0 1 -1>.

[0229] In the surface emitting laser 10-5, the length D in the length direction of the high refractive index region 106a is L1 is the length of the major axis passing through the area centroid C1, and the length D in the width direction of the high refractive index region 106a is S1 is the length of the minor axis passing through the area centroid C1.

[0230] The surface emitting laser 10-5 can be manufactured by a manufacturing method substantially similar to the method of manufacturing the surface emitting laser 10-1 according to Embodiment 1. At this time, in the oxidation treatment for forming the oxidized shrinkage layer 106, for example, the oxidized layer 106S of the mesa having a major axis length of 22 μm, a minor axis length of 20 μm, and a second ratio r2 of 1.10 is oxidized by 6.75 μm from the outer peripheral side to the center side, whereby the oxidized shrinkage layer 106 has a quadrilateral shape (for example, a shape in which a rhombus is deformed in the length direction) having a major axis length of 8.5 μm in a plan view, a minor axis length of 6.5 μm, and a first ratio r1 of 1.31. At this time, the width direction Sd1 of the high refractive index region 106a extends in the direction along the crystal direction <0 1 -1> of the substrate 101, and due to the crystal anisotropy associated with the substrate tilt, etc., the length direction Ld1 causes a difference in the oxidation rate of the oxide layer 106S, so that the oxidized shrinkage layer 106 has a quadrilateral shape (modified rhombus shape) that is symmetrical with respect to the length direction Ld2 of the second structure ST2 and asymmetrical with respect to the width direction Sd2 of the second structure ST2. The area centroid C1 of the high refractive index region 106a is offset by δ1 (for example, 0.20 μm) from the area centroid C2 of the second structure ST2 in the length direction Ld2 of the second structure ST2. This offset is an offset caused by crystal anisotropy, and the asymmetry can be enhanced without changing the first and second ratios r1 and r2. On the other hand, since the anode electrode 108 has a ring shape (ring shape) centered on the area centroid C2 of the second structure ST2, a bias current injection can be performed into the oxidized shrinkage layer 106 in which the area centroid C1 is offset from the area centroid C2. Therefore, the asymmetry of the oxidation shrinkage layer 106 can be enhanced, and the stabilization of the width direction mode can be promoted.

[0231] It should be noted that in the surface emitting laser 10-5, the length direction of the second structure ST2 and the high refractive index region 106a may form an angle by a method similar to the method of the surface emitting laser 10-4 according to Embodiment 4, or the area centroids C1 and C2 may be moved in the width direction as a supplement or alternative to the movement in the length direction. In this case, the offset δ2 in the width direction is preferably 0.10 μm or less. In the surface emitting laser 10-5, δ1 may be greater than 0.20 μm. The length direction Ld2 of the second structure ST2 may extend in the direction along the crystal direction <0 1 -1> of the substrate 101.

[0232] <6. Surface-Emitting Laser According to Example 6 of First Embodiment of the Present Technology>

[0233] Fig.15 1 is a plan view of a surface emitting laser 10-6 according to Example 6 of the first embodiment of the present technology. Fig.15As shown, the surface emitting laser 10-6 has a configuration similar to that of the surface emitting laser 10-1 according to Example 1, but, in a plan view, both the second structure ST2 and the high refractive index region 106a have a closed curve shape that is symmetrical with respect to the length direction and asymmetrical with respect to the width direction (for example, a deformed elliptical shape), and the area centroid C1 of the high refractive index region 106a and the area centroid C2 of the second structure ST2 do not coincide with each other.

[0234] In the surface emitting laser 10-6, the cross section of the second structure ST2 has an elliptical shape without changes in the straight line portion and the top portion. Therefore, the surface emitting laser 10-6 is comparable to the surface emitting laser 10-1 according to Embodiment 1 in film thickness uniformity and step coverage.

[0235] In the surface emitting laser 10-6, the length direction of the second structure ST2 and the high refractive index region 106a coincide with each other, and the width direction does not coincide with each other. The displacement amount δ1 of the area centroid of the second structure ST2 and the high refractive index region 106a in the length direction is, for example, 0.20 μm.

[0236] In the surface emitting laser 10-6, the substrate 101 is an inclined substrate whose substrate plane orientation is a plane orientation inclined toward the crystal plane (100) or the crystal plane (0-1-1), and the side direction Sd2 of the mesa structure as the second structure ST2 extends in the direction along the crystal direction <01-1>.

[0237] In the surface emitting laser 10-6, the length D in the length direction of the high refractive index region 106a is L1 is the length of the major axis passing through the area centroid C1, and the length D in the width direction of the high refractive index region 106a is S1 is the length of the minor axis passing through the area centroid C1.

[0238] The surface emitting laser 10 - 6 can be manufactured by a manufacturing method substantially similar to the method for manufacturing the surface emitting laser 10 - 5 according to Embodiment 5.

[0239] According to the surface emitting laser 10 - 6 , the effect of the surface emitting laser 10 - 1 according to Embodiment 1 and the effect of the surface emitting laser 10 - 5 according to Embodiment 5 are obtained.

[0240] It should be noted that in the surface emitting laser 10-6, the length direction of the second structure ST2 and the high refractive index region 106a may form an angle by a method similar to the method of the surface emitting laser 10-4 according to Example 4, or the area centroids C1 and C2 may be moved in the width direction as a supplement or alternative to the movement in the length direction. In this case, the offset δ2 in the width direction is preferably 0.10 μm or less. In the surface emitting laser 10-6, δ1 may be greater than 0.20 μm. The length direction Ld2 of the second structure ST2 may extend in the direction along the crystal direction <0 1 -1> of the substrate 101.

[0241] <7. Surface-Emitting Laser According to Example 7 of First Embodiment of the Present Technology>

[0242] Fig.16 1 is a plan view of a surface emitting laser 10-7 according to Example 7 of the first embodiment of the present technology. Fig.16 As shown in , the surface emitting laser 10 - 7 has a configuration similar to that of the surface emitting laser 10 - 1 according to Embodiment 1, but the second structure ST2 and the high refractive index region 106 a each have a track shape in a plan view.

[0243] The surface emitting laser 10-7 has a rail shape in which the cross section of the second structure ST2 has a straight line portion and has no top. Therefore, the film thickness uniformity and step coverage of the surface emitting laser 10-7 are slightly lower than those of the surface emitting laser 10-1 according to Embodiment 1.

[0244] In the surface emitting laser 10-7, the area centroid C2 of the second structure ST2 and the area centroid C1 of the high refractive index region 106a coincide with each other. In the surface emitting laser 10-7, each of the second structure ST2 and the high refractive index region 106a is symmetrical with respect to each of the length direction and the width direction in a plan view.

[0245] In the surface emitting laser 10-7, the length D in the length direction of the high refractive index region 106a is L1 is the length of the major axis passing through the area centroid C1, and the length D in the width direction of the high refractive index region 106a is S1 is the length of the minor axis passing through the area centroid C1.

[0246] The surface emitting laser 10 - 7 can be manufactured by a manufacturing method substantially similar to the method for manufacturing the surface emitting laser 10 - 1 according to Embodiment 1.

[0247] According to the surface emitting laser 10 - 7 , although the film thickness uniformity and the step coverage are slightly inferior, effects similar to those of the surface emitting laser 10 - 1 according to Embodiment 1 are basically obtained.

[0248] It should be noted that in the surface emitting laser 10-7, the length direction of the second structure ST2 and the high refractive index region 106a may form an angle by a method similar to that of the surface emitting laser 10-4 according to Embodiment 4, or the area centroids C1 and C2 may be moved in the width direction and / or the length direction.

[0249] <8. Surface-Emitting Laser According to Example 8 of First Embodiment of the Present Technology>

[0250] Fig.17 1 is a plan view of a surface emitting laser 10-8 according to Example 8 of the first embodiment of the present technology. Fig.17 As shown in , the surface emitting laser 10-8 has a configuration similar to that of the surface emitting laser 10-1 according to Embodiment 1, but the second structure ST2 and the high refractive index region 106a each have a rounded rectangular shape (rectangular shape with rounded corners) in a plan view.

[0251] The surface emitting laser 10-8 has a rounded rectangular shape in which the cross section of the second structure ST2 has a straight line portion and has no top. Therefore, compared with the surface emitting laser 10-1 according to Embodiment 1, the surface emitting laser 10-8 is slightly inferior in film thickness uniformity and step coverage.

[0252] In the surface emitting laser 10-8, the area centroid C2 of the second structure ST2 and the area centroid C1 of the high refractive index region 106a coincide with each other. In the surface emitting laser 10-8, each of the second structure ST2 and the high refractive index region 106a is symmetrical with respect to each of the length direction and the width direction in a plan view.

[0253] In the surface emitting laser 10 - 8 , the length D in the length direction of the high refractive index region 106 a is L1 is the length of the major axis passing through the area centroid C1, and the length D in the width direction of the high refractive index region 106a is S1 is the length of the minor axis passing through the area centroid C1.

[0254] The surface emitting laser 10 - 8 can be manufactured by a manufacturing method substantially similar to the method for manufacturing the surface emitting laser 10 - 1 according to Embodiment 1.

[0255] According to the surface emitting laser 10 - 8 , although the film thickness uniformity and the step coverage are slightly inferior, effects similar to those of the surface emitting laser 10 - 1 according to Embodiment 1 are basically obtained.

[0256] It should be noted that in the surface emitting laser 10-8, the length direction of the second structure ST2 and the high refractive index region 106a may form an angle by a method similar to that of the surface emitting laser 10-4 according to Embodiment 4, or the area centroids C1 and C2 may be moved in the width direction and / or the length direction.

[0257] <9. Surface-Emitting Laser According to Example 9 of First Embodiment of the Present Technology>

[0258] Fig.18 1 is a plan view of a surface emitting laser 10-9 according to Example 9 of the first embodiment of the present technology. Fig.18 As shown, the surface emitting laser 10 - 9 has a configuration similar to that of the surface emitting laser 10 - 1 according to Embodiment 1, but both the second structure ST2 and the high refractive index region 106 a have a rectangular shape in a plan view.

[0259] The surface emitting laser 10-9 has a rectangular shape in which the cross section of the second structure ST2 has a straight line portion and a top portion. Therefore, the surface emitting laser 10-9 is inferior to the surface emitting laser 10-1 according to Embodiment 1 in terms of film thickness uniformity and step coverage. However, compared with a surface emitting laser in which the angle formed by the two sides forming the top is an acute angle, the surface emitting laser 10-9 is excellent in terms of film thickness uniformity and step coverage.

[0260] In the surface emitting laser 10-9, the area centroid C2 of the second structure ST2 and the area centroid C1 of the high refractive index region 106a coincide with each other. In the surface emitting laser 10-9, in a plan view, each of the second structure ST2 and the high refractive index region 106a is symmetrical with respect to each of the length direction and the width direction.

[0261] In the surface emitting laser 10-9, the length D in the length direction of the high refractive index region 106a is L1 is the length of the major axis passing through the area centroid C1, and the length D in the width direction of the high refractive index region 106a is S1 is the length of the minor axis passing through the area centroid C1.

[0262] The surface emitting laser 10 - 9 can be manufactured by a manufacturing method substantially similar to the method for manufacturing the surface emitting laser 10 - 1 according to Embodiment 1.

[0263] According to the surface emitting laser 10 - 9 , although the film thickness uniformity and the step coverage are inferior, effects similar to those of the surface emitting laser 10 - 1 according to Embodiment 1 are basically obtained.

[0264] It should be noted that in the surface emitting laser 10-9, the length direction of the second structure ST2 and the high refractive index region 106a may form an angle by a method similar to that of the surface emitting laser 10-4 according to Embodiment 4, or the area centroids C1 and C2 may be moved in the width direction and / or the length direction.

[0265] <10. Surface-Emitting Laser According to Example 10 of First Embodiment of the Present Technology>

[0266] Fig.19 1 is a plan view of a surface emitting laser 10-10 according to Example 10 of the first embodiment of the present technology. Fig.19 As shown in , the surface emitting laser 10-10 has a configuration similar to that of the surface emitting laser 10-1 according to Embodiment 1, but both the second structure ST2 and the high refractive index region 106a have polygonal shapes (eg, octagonal shapes) in a plan view.

[0267] In the surface emitting laser 10-10, the cross section of the second structure ST2 has an octagonal shape having a straight line portion and a top (however, since the angle formed by the two sides forming the top is an obtuse angle, the influence on the uniformity of film thickness and the step coverage is relatively small). That is, the surface emitting laser 10-10 is slightly inferior to the surface emitting laser 10-1 according to Embodiment 1 in terms of film thickness uniformity and step coverage.

[0268] In the surface emitting laser 10-10, the area centroid C2 of the second structure ST2 and the area centroid C1 of the high refractive index region 106a coincide with each other. In the surface emitting laser 10-9, in a plan view, each of the second structure ST2 and the high refractive index region 106a is symmetrical with respect to each of the length direction and the width direction.

[0269] In the surface emitting laser 10-10, the length D in the length direction of the high refractive index region 106a is L1 is the length of the major axis passing through the area centroid C1, and the length D in the width direction of the high refractive index region 106a is S1 is the length of the minor axis passing through the area centroid C1.

[0270] The surface emitting laser 10 - 10 can be manufactured by a manufacturing method substantially similar to the method for manufacturing the surface emitting laser 10 - 1 according to Embodiment 1.

[0271] According to the surface emitting laser 10 - 10 , although the film thickness uniformity and the step coverage are slightly inferior, effects similar to those of the surface emitting laser 10 - 1 according to Embodiment 1 are basically obtained.

[0272] It should be noted that in the surface emitting laser 10-10, the length direction of the second structure ST2 and the high refractive index region 106a may form an angle by a method similar to that of the surface emitting laser 10-4 according to Embodiment 4, or the area centroids C1 and C2 may be moved in the width direction and / or the length direction. In a plan view, the second structure ST2 and the high refractive index region 106a may have a polygonal shape other than an octagon.

[0273] <11. Surface-Emitting Laser According to Example 11 of First Embodiment of the Present Technology>

[0274] Fig. 20 1 is a plan view of a surface emitting laser 10-11 according to Example 11 of the first embodiment of the present technology. Fig. 20 As shown in , the surface emitting laser 10-11 has a configuration similar to that of the surface emitting laser 10-1 according to Embodiment 1, but the second structure ST2 and the high refractive index region 106a each have a closed curve shape having a top in a plan view (e.g., a deformed ellipse whose top is set to an ellipse).

[0275] In the surface emitting laser 10-11, the cross section of the second structure ST2 has a modified elliptical shape with a top without a straight line portion (however, because the top is not so sharp, the influence on the film thickness uniformity and coverage is relatively small), that is, the surface emitting laser 10-11 is slightly inferior in film thickness uniformity and coverage compared with the surface emitting laser 10-1 according to Example 1.

[0276] In the surface emitting laser 10-11, the area centroid C2 of the second structure ST2 and the area centroid C1 of the high refractive index region 106a coincide with each other. In the surface emitting laser 10-11, each of the second structure ST2 and the high refractive index region 106a is symmetrical with respect to each of the length direction and the width direction in a plan view.

[0277] In the surface emitting laser 10-11, the length D in the length direction of the high refractive index region 106a is L1 is the length of the major axis passing through the area centroid C1, and the length D in the width direction of the high refractive index region 106a is S1 is the length of the minor axis passing through the area centroid C1.

[0278] The surface emitting laser 10 - 11 can be manufactured by a manufacturing method substantially similar to the method for manufacturing the surface emitting laser 10 - 1 according to Embodiment 1.

[0279] According to the surface emitting laser 10 - 11 , although the film thickness uniformity, the film thickness uniformity, and the step coverage are slightly inferior, substantially similar effects to those of the surface emitting laser 10 - 1 according to Embodiment 1 are obtained.

[0280] It should be noted that in the surface emitting laser 10-11, the length direction of the second structure ST2 and the high refractive index region 106a may form an angle by a method similar to that of the surface emitting laser 10-4 according to Embodiment 4, or the area centroids C1 and C2 may be moved in the width direction and / or the length direction.

[0281] <12. Surface-Emitting Laser According to Example 1 of Second Embodiment of the Present Technology>

[0282] <<Configuration of surface emitting laser>>

[0283] Fig.21 is a cross-sectional view (part 1) of a surface emitting laser 20 - 1 according to Example 1 of the second embodiment of the present technology. Fig. 22 is a cross-sectional view (part 2) of a surface emitting laser 20 - 1 according to Example 1 of the second embodiment of the present technology. Fig.23 is a cross-sectional view (part 3) of the surface emitting laser 20 - 1 according to Example 1 of the second embodiment of the present technology. Fig.24 is a plan view of a surface emitting laser 20 - 1 according to Example 1 of the second embodiment of the present technology.

[0284] Fig.21 It is along Fig.24 A cross-sectional view taken along line 21-21 in FIG. Fig. 22 It is along Fig.24 A cross-sectional view taken along line 22-22 in FIG. Fig.23 It is along Fig.24 A cross-sectional view taken along line 23-23 in FIG.

[0285] like Figures 21 to 24As shown in , the surface emitting laser 20-1 has a configuration substantially similar to the surface emitting laser 10-1 according to Example 1 of the first embodiment, except that a low dielectric constant region 112A surrounding the second structure ST2 is provided, and the configurations of the anode electrode 108 and the cathode electrode 109 are different. Hereinafter, the structure including the substrate 101, the first reflector 102, the first cladding layer 103, the active layer 104, the second cladding layer 105, the oxidized shrinkage layer 106, the second reflector 107, and the contact layer 111 is referred to as a "stacked structure LS".

[0286] In the surface emitting laser 20-1, the stacked structure LS includes a first structure ST1 and a second structure ST2. Here, the first structure ST1 includes a substrate 101 and a portion (lower portion) of the first reflector 102. The second structure ST2 includes the other portion (upper portion) of the first reflector 102, a first cladding layer 103, an active layer 104, a second cladding layer 105, an oxidized shrink layer 106, a second reflector 107, and a contact layer 111.

[0287] The second structure ST2 is divided into a mesa shape by a groove T1 (groove) provided on the upper surface of the stacked structure LS. The groove T1 is a surrounding groove with the outer peripheral surface of the second structure ST2 as the inner peripheral surface. The bottom surface of the groove T1 is preferably at least at a position lower than the oxidation shrinkage layer 106 (a position close to the rear surface (lower surface) of the substrate 101). Here, the bottom surface of the groove T1 is in the first reflector 102. A portion of the stacked structure LS is covered by an insulating film 110. The insulating film 110 on the second structure ST2 is provided with an annular contact hole CHa exposing a portion of the contact layer 111 in a plan view.

[0288] In the surface emitting laser 20-1, for example, the second structure ST2 is a mesa structure having an elliptical shape in a plan view. In the surface emitting laser 20-1, the anode electrode 108 has a ring-shaped (ring-shaped) electrode portion 108a provided on the second structure ST2. The electrode portion 108a is provided in a ring shape in a manner of contacting the contact layer 111 in the contact hole CHa when viewed from above. The electrode portion 108a surrounds the light emitting region of the active layer 104 when viewed from above.

[0289] The low dielectric constant region 112A is a region having a dielectric constant lower than that of a semiconductor (having high insulation). As a material of the low dielectric constant region 112A, for example, benzocyclobutene (BCB) is used. The low dielectric constant region 112A is provided on the stacked structure LS via the insulating film 110 .

[0290] The low dielectric constant region 112A includes a surrounding first portion 112a embedded in the trench T1 and a second portion 112b continuous with the first portion 112a and surrounding the electrode portion 108a. In addition, the inner peripheral surface of the second portion 112b is in contact with the outer peripheral surface of the annular electrode portion 108a via the insulating film 113. That is, the inner peripheral surface of the second portion 112b is along the outer peripheral surface of the electrode portion 108a. The second portion 112b includes: an inner peripheral portion 112b1 (surrounding portion), which is arranged on the second structure ST2 via the insulating film 110; and an extension portion 112b2, which extends from the inner peripheral portion 112b1 in a plane (for example, along the direction of line 22-22) in a direction away from the second structure ST2 (see Fig. 22 ). The inner edge of the first portion 112a has an elliptical shape along the outer peripheral surface of the second structure ST2 (for example, an elliptical shape with a major axis length of 44 μm and a minor axis length of 40 μm), and the inner edge of the inner peripheral portion 112b1 of the second portion 112b has a circular shape (for example, a circular shape with a diameter of 40 μm). For this reason, in the second structure ST2, different stresses are generated in the length direction and the width direction (specifically, a greater stress is generated in the length direction than in the width direction), and the effect of promoting the asymmetry of the oxidative shrinkage layer 106 can be obtained. In addition, the ratio of the length of the inner peripheral edge of the inner peripheral portion 112b1 of the second portion 112b of the low dielectric constant region 112A to the length in the width direction is not limited to 1, and is preferably greater than 1.00 and less than 1.10.

[0291] On the extension 112b2 of the low dielectric constant region 112A, a pad 108b of the anode electrode 108 is provided via an insulating film 113. The pad 108b has, for example, a substantially circular shape in a plan view, and is connected to the electrode portion 108a via a connecting portion 108c of the anode electrode 108. The insulating film 113 includes, for example, a material similar to that of the insulating film 110.

[0292] The anode electrode 108 is covered by an insulating film 115. A contact hole CHb for exposing a pad 108b of the anode electrode 108 is provided on the insulating film 115. The pad 108b exposed through the contact hole CHb is electrically connected to the anode side of the laser driver. The insulating film 115 includes, for example, a material similar to that of the insulating film 110.

[0293] like Figure 21 to Figure 24 As shown, the surface emitting laser 20-1 includes a first cathode electrode 109A provided on the front surface (upper surface) side of the substrate 101 and a second cathode electrode 109B of a solid shape provided on the rear surface (lower surface) of the substrate 101. In a plan view, the first cathode electrode 109A is provided along the line 21-21 (see Fig.24) direction from the anode electrode 108. The first cathode electrode 109A includes: an electrode portion 109A1, which is arranged on the bottom surface of the trench T2 (recess) provided on the upper surface of the stacked structure LS; a pad 109A2, which is arranged along the line 23-23 (see FIG. 2 ) when viewed from above; Fig.24 ) direction away from the electrode portion 109A1; and a connecting portion 109A3, which connects the electrode portion 109A1 and the pad 109A2. The pad 109A2 is arranged on the low dielectric constant region 112B via the insulating film 113. The low dielectric constant region 112B is arranged on the contact layer 111 via the insulating film 110. The low dielectric constant region 112B includes the same material (for example, BCB) as the above-mentioned low dielectric constant region 112A. One end of the connecting portion 109A3 is connected to the electrode portion 109A1 on the bottom surface of the trench T2, the middle portion is arranged on the side of the trench T2 and the peripheral area of ​​the trench T2 via the insulating film 110, and the other end is connected to the pad 109A2. The bottom surface of the trench T2 is preferably at least located at a position lower than the active layer 104 (close to the back side (lower surface) of the substrate 101). Here, the bottom surface of the trench T2 is consistent with the upper surface of the substrate 101. As an example, each of the electrode portion 109A1 and the pad 109A2 has a substantially circular shape in a plan view (see FIG. Fig.24 ). The pad 109A2 and the second cathode electrode 109B are electrically connected to the cathode side of the laser driver.

[0294] <<Method for manufacturing a surface emitting laser>>

[0295] In the following, reference will be made to Fig.25 Flowchart and Fig.26 A to Fig.35 The cross-sectional view of B describes a method for manufacturing the surface emitting laser 20 - 1 . Fig.26 A to Fig.35 B corresponds to the Fig.24 A cross-sectional view of a section taken along line 21-21 in FIG.

[0296] Here, as an embodiment, by a semiconductor manufacturing method using a semiconductor manufacturing apparatus, a plurality of surface emitting lasers 20-1 are simultaneously generated on one wafer (hereinafter, for convenience, also referred to as "substrate 101") as a base material of a substrate 101. Next, a plurality of continuous and integrated surface emitting lasers 20-1 are separated from each other to obtain a plurality of chip-shaped surface emitting lasers 20-1.

[0297] In a first step S11, a multilayer body is generated (see Fig.26A). Specifically, for example, a first reflector 102, a first cladding layer 103, an active layer 104, a second cladding layer 105, a second reflector 107, the second reflector 107 having an oxide layer 106S (for example, an AlAs layer or an AlGaAs layer as a material of the oxide shrinkage layer 106 is provided), and a contact layer 111 is stacked in this order (for example, a substrate 101 (for example, an n-GaAs substrate) is formed by a metal organic chemical vapor deposition (MOCVD) method at a growth temperature of 605°C on the substrate 101 as a growth substrate. It should be noted that when MOCVD is performed, for example, trimethylgallium ((CH3)3Ga) is used as a source gas for gallium, for example, trimethylaluminum ((CH3)3Al) is used as a source gas for aluminum, for example, trimethylindium ((CH3)3In) is used as a source gas for indium, and for example, trimethylarsenic (((CH3)3As) is used as a source gas for As. In addition, as a raw material gas for silicon, for example, monosilane (SiH4) is used, and as a raw material gas for carbon, for example, carbon tetrabromide (CBr4) is used.

[0298] In the next step S12, a separation groove 101a is formed. The separation groove 101a is a groove for separating adjacent surface emitting lasers 20-1 generated on the wafer by dicing. First, a resist pattern RP1 (see FIG. 1 ) covering a portion of the upper surface of the multilayer body except for a portion where the separation groove 101a is to be formed is formed by photolithography. Fig.26 B). Next, using the resist pattern RP1 as a mask, the multilayer body is etched by inductively coupled plasma (ICP) dry etching using, for example, Cl2, SiCl4, or Ar (see Fig. 27 A). The etching depth at this time is set to a level until the etching bottom surface is located in the substrate 101. Thereafter, the resist pattern RP1 (see Fig. 27 B).

[0299] In the next step S13, trenches T1 and T2 are formed. Specifically, first, a resist pattern RP2 (see FIG. 1 ) is formed by photolithography to cover the portion of the upper surface of the multilayer body except for the portion where the trench T1 is to be formed. Fig.28 A). Next, using the resist pattern RP2 as a mask, the multilayer body is etched by inductively coupled plasma (ICP) dry etching using, for example, Cl2, SiCl4, or Ar, until the etching bottom surface is located in the first reflector 102, and a groove T1 having an elliptical ring shape in a plan view is formed. Thus, a mesa structure having an elliptical shape in a plan view (for example, an ellipse with a major axis length of 22 μm and a minor axis length of 20 μm) is formed, in which the inner peripheral surface of the groove T1 serves as the outer peripheral surface ( Fig.28 B). Next, the resist pattern RP2 is removed (see Fig.29A). Next, a resist pattern RP3 is formed by photolithography to cover a portion other than a portion where the trench T2 is to be formed on the upper surface of the multilayer body (see Fig.29 B). Next, using the resist pattern RP3 as a mask, the multilayer body is etched by inductively coupled plasma (ICP) dry etching using, for example, Cl2, SiCl4, or Ar, until the etching bottom surface reaches the upper surface of the substrate 101 to form a groove T2 having a circular shape in plan view (see FIG. Fig.30 A). Finally, the resist pattern RP3 is removed (see Fig.30 B). Note that trench T1 may be formed after trench T2 is formed.

[0300] In the next step S14, an oxidized shrink layer 106 (see Fig.31 ). Specifically, the terrace having an elliptical shape in a plan view formed in step S13 is exposed to a high-temperature water vapor atmosphere, and the oxide layer 106S is oxidized by a predetermined distance (for example, 6.75 μm) from the outer peripheral side toward the center side. As a result, an oxidized shrinkage layer 106 is formed in which an unoxidized region having an elliptical shape in a plan view (for example, an ellipse having a major axis length of 8.5 μm and a minor axis length of 6.5 μm) is surrounded by an oxidized region as a low refractive index region 106b.

[0301] In the next step S15, a thin insulating film 110 (see Fig.32 A).

[0302] In the next step S16, the anode electrode 108 is formed. Specifically, first, a portion of the insulating film 110 is removed by photolithography and etching to form a ring-shaped contact hole CHa in a plan view (see FIG. 1 ). Fig.32 B). Next, the anode electrode 108 is formed, for example, by a lift-off method, so that the electrode portion 108a has a ring shape (for example, an inner diameter of 12.6 μm and an outer diameter of 18.0 μm) (see Fig.33 A) For example, a film of the electrode material of the anode electrode 108 is formed using vacuum deposition, sputtering, or the like.

[0303] In the next step S17, low dielectric constant regions 112A and 112B are formed (see Fig.33B). Specifically, first, a thick film of BCB, which is a low dielectric constant material, is formed on the entire surface. Next, unnecessary portions of the BCB film are removed by photolithography and etching. Thus, a low dielectric constant region 112A is formed, and a low dielectric constant region 112B is formed, wherein the inner peripheral surface of the first portion 112a is along the outer peripheral surface of the second structure ST2 having an elliptical shape in a plan view, and the inner peripheral surface of the second portion 112b (the inner edge of the inner peripheral portion 112b1) is along the outer peripheral surface of the annular electrode portion 108a.

[0304] In the next step S18, an insulating film 113 (see Fig.34 A) Specifically, first, the insulating film 113 is formed on the entire surface. Next, the insulating film 113 other than the insulating film 113 covering the low dielectric constant regions 112A and 112B is removed by photolithography and etching.

[0305] In the final step S19, a first cathode electrode 109A is formed (see Fig.34 B). Specifically, the first cathode electrode 109A is formed so that the electrode portion 109A1 has a circular shape on the bottom surface of the trench T2 (see Fig.34 B) At this time, for example, vacuum deposition, sputtering, or the like is used to form a film of the electrode material of the first cathode electrode 109A.

[0306] In the next step S20, an insulating film 115 (see Fig.35 A). Specifically, first, the insulating film 115 is formed on the entire surface. Next, at least the insulating film 115 covering the pad 108b of the anode electrode 108 and the insulating film 115 covering the pad 109A2 of the first cathode electrode 109A are removed by photolithography and etching.

[0307] In the final step S21, a second cathode electrode 109B (see Fig.35 B) Specifically, the second cathode electrode 109B is formed in a solid shape on the back surface of the substrate 101 by, for example, a lift-off method. At this time, for example, a film of an electrode material of the second cathode electrode 109B is formed using vacuum deposition, sputtering, or the like.

[0308] Note that the order of steps S15 and S16 may be substantially reversed. That is, after forming the anode electrode 108 on the mesa, the insulating film 110 may be formed on the entire surface, and a portion of the insulating film 110 covering the anode electrode 108 may be removed by photolithography and etching.

[0309] <13. Surface-Emitting Laser According to Example 2 of Second Embodiment of the Present Technology>

[0310] Fig.36is a plan view of a surface emitting laser 20 - 2 according to Example 2 of the second embodiment of the present technology.

[0311] like Fig.36 As shown in FIG. 1 , the surface emitting laser 20-2 has a configuration similar to that of the surface emitting laser 20-1 according to Example 1, but the high refractive index region 106a has a closed curve shape (e.g., a modified ellipse) similar to that of the surface emitting laser 10-6 according to Example 6 of the first embodiment (see FIG. 1 ). Fig.15 ).

[0312] In the surface emitting laser 20-2, the length direction of the high refractive index region 106a and the length direction of the second structure ST2 are consistent with each other, and the width direction is offset. That is, the area centroid C1 of the high refractive index region 106a and the area centroid C2 of the second structure ST2 are offset by δ1 (for example, 0.20 μm or more) in the length direction.

[0313] The surface emitting laser 20 - 2 can be manufactured by a control method in which the characteristic points of the method for manufacturing the surface emitting laser 10 - 6 according to Embodiment 6 of the first embodiment are applied to the method for manufacturing the surface emitting laser 20 - 1 according to Embodiment 1.

[0314] According to the surface emitting laser 20 - 2 , in addition to the effect of the surface emitting laser 20 - 1 , the effect of the surface emitting laser 10 - 6 can be obtained.

[0315] <14. Surface-Emitting Laser According to Example 3 of Second Embodiment of the Present Technology>

[0316] Fig.37 is a cross-sectional view (part 1) of a surface emitting laser 20 - 3 according to Example 3 of the second embodiment of the present technology. Fig.38 is a cross-sectional view (part 2) of a surface emitting laser 20 - 3 according to Example 3 of the second embodiment of the present technology. Fig.39 is a plan view of a surface emitting laser 20 - 3 according to Example 3 of the second embodiment of the present technology. Fig.37 It is along Fig.39 A cross-sectional view taken along line 37-37 in FIG. Fig.38 is along Fig.39 A cross-sectional view taken along line 38-38 in FIG.

[0317] The surface emitting laser 20-3 has a configuration similar to that of the surface emitting laser 20-1 according to Embodiment 1, but an ion implantation region IIA ( Fig.37 and Fig.38 It should be noted that the ion implantation area IIA may be provided in the first structure ST1 in addition to the second structure ST2.

[0318] In the ion implantation region IIA, the inner edge IIAa has a substantially circular shape in a plan view (see Fig.39 ). Therefore, it is easy to control the position of the inner edge when performing ion implantation. Strictly speaking, the inner edge IIAa of the ion implantation area IIA has a long side direction and a short side direction when viewed from above. In this case, the ratio of the length IDL in the length direction of the inner edge of the ion implantation area IIA to the length IDS in the width direction is preferably greater than 1.00 and less than 1.10. The outer edge of the ion implantation area IIA has, for example, a roughly elliptical shape that is consistent with the outer edge of the second structure ST2 when viewed from above. As ion species used for the ion implantation area IIA, H and B can be listed.

[0319] The refractive index of the ion implantation area IIA is lower than that of the area on the inner diameter side (non-ion implantation area), which has an optical confinement effect. Since the inner edge IIAa of the ion implantation area IIA has shape anisotropy in the long side direction and the short side direction when viewed from above, anisotropy appears in the refractive index distribution, and the width direction mode can be further stabilized.

[0320] In a plan view, the center of the inner edge IIAa of the ion implantation region IIA coincides with the center of the electrode portion 108a of the anode electrode 108. The length in the long side direction and the length in the short side direction of the inner edge IIAa of the ion implantation region IIA are longer than the inner diameter of the electrode portion 108a of the anode electrode 108. Therefore, the contact portion of the contact layer 111 and the anode electrode 108 can be a non-ion implantation region, and an increase in resistance of at least a portion of the contact portion can be suppressed.

[0321] The surface emitting laser 20 - 3 can be manufactured by a control method in which an ion implantation process is combined with the method for manufacturing the surface emitting laser 20 - 1 according to Embodiment 1.

[0322] According to the surface emitting laser 20 - 3 , in addition to the effect of the surface emitting laser 20 - 1 , the width direction mode can be further stabilized.

[0323] <15. Surface-Emitting Laser According to Example 4 of Second Embodiment of the Present Technology>

[0324] Fig.40 A is a plan view of a surface emitting laser 20 - 4 according to Example 4 of the second embodiment of the present technology. Fig.40 B is a bottom view of the surface emitting laser 20 - 4 according to Example 4 of the second embodiment of the present technology.

[0325] like Fig.40 A and Fig.40 As shown in FIG. 2B , the surface emitting laser 20 - 4 has a configuration similar to that of the surface emitting laser 20 - 1 according to Embodiment 1, except that the cathode electrode 109 is provided in a solid shape only on the back surface (lower surface) of the substrate 101 .

[0326] The surface emitting laser 20 - 4 can be manufactured by a manufacturing method conforming to the method for manufacturing the surface emitting laser 20 - 1 according to Embodiment 1.

[0327] According to the surface emitting laser 20 - 4 , since the cathode electrode is not provided on the upper surface side of the substrate 101 , the IV characteristic is poor, but the manufacturing is easy.

[0328] <16. Modification of this Technology>

[0329] The present technology is not limited to each of the above-described embodiments and examples, and various modifications may be made.

[0330] (Surface emitting laser according to first modified example of first embodiment of the present technology)

[0331] Fig.41 A is a cross-sectional view (part 1) of a surface emitting laser 10 - M1 according to a first modification example of the first embodiment of the present technology. Fig.41 B is a cross-sectional view (part 2) of the surface emitting laser 10 - M1 according to the first modification example of the first embodiment of the present technology. Fig.41 A is Figure 1 A corresponding cross-sectional view, Fig.41 B is Figure 1 B corresponds to the cross-sectional view (the same applies to the following modified examples).

[0332] like Fig.41 A and Fig.41 As shown in FIG. 1B, the surface emitting laser 10-M1 has a configuration similar to that of any one of the surface emitting lasers 10-1 to 10-11 according to Examples 1 to 11 of the first embodiment, except that the bottom surface of the mesa structure as the second structure ST2 is located in the first reflector 102 and the cathode electrode 109 is provided on the region of the first reflector 102 around the mesa structure. In the surface emitting laser 10-M1, a non-doped semiconductor substrate (e.g., an i-GaAs substrate) can also be used as the substrate 101.

[0333] (Surface emitting laser according to second modification example of first embodiment of the present technology)

[0334] Fig.42A is a cross-sectional view (part 1) of a surface emitting laser 10 - M2 according to a second modification example of the first embodiment of the present technology. Fig.42 B is a cross-sectional view (part 2) of the surface emitting laser 10 - M2 according to the second modification example of the first embodiment of the present technology.

[0335] like Fig.42 A and Fig.42 As shown in FIG. 2B , the surface emitting laser 10 - M2 has a configuration similar to any of the surface emitting lasers 10 - 1 to 10 - 11 according to Embodiments 1 to 11 of the first embodiment, except that an oxidized shrink layer 106 is arranged in the first reflector 102 .

[0336] (Surface emitting laser according to third modification example of first embodiment of the present technology)

[0337] Fig.43 A is a cross-sectional view (part 1) of a surface emitting laser 10 - M3 according to a third modification example of the first embodiment of the present technology. Fig.43 B is a cross-sectional view (part 2) of the surface emitting laser 10 - M3 according to the third modification example of the first embodiment of the present technology.

[0338] like Fig.43 A and Fig.43 As shown in FIG. 1B, the surface emitting laser 10-M3 has a configuration similar to that of any of the surface emitting lasers 10-1 to 10-11 according to embodiments 1 to 11 of the first embodiment, except that the oxidized shrink layer 106 is provided in the second cladding layer 105. Note that the oxidized shrink layer 106 may be provided in the first cladding layer 103 instead of in the second cladding layer 105.

[0339] (Surface emitting laser according to fourth modification example of first embodiment of the present technology)

[0340] Fig.44 A is a cross-sectional view (part 1) of a surface emitting laser 10 - M4 according to a fourth modification example of the first embodiment of the present technology. Fig.44 B is a cross-sectional view (part 2) of the surface emitting laser 10 - M4 according to the fourth modification example of the first embodiment of the present technology.

[0341] like Fig.44 A and Fig.44As shown in B, the surface emitting laser 10-M4 has a configuration similar to that of any one of the surface emitting lasers 10-1 to 10-11 of Examples 1 to 11 according to the first embodiment, but the oxidized shrinkage layer 106 is provided in the second cladding layer 105, the bottom surface of the mesa structure as the second structure ST2 is located in the first cladding layer 103, and the cathode electrode 109 is mounted on the area of ​​the first cladding layer 103 around the mesa structure.

[0342] (Surface emitting laser according to fifth modification example of first embodiment of the present technology)

[0343] Fig.45 A is a cross-sectional view (part 1) of a surface emitting laser 10 - M5 according to a fifth modification example of the first embodiment of the present technology. Fig.45 B is a cross-sectional view (part 2) of a surface emitting laser 10 - M5 according to a fifth modification example of the first embodiment of the present technology.

[0344] like Fig.45 A and Fig.45 As shown in FIG. 2B , the surface emitting laser 10-M5 has a configuration similar to any one of the surface emitting lasers 10-1 to 10-11 of Embodiments 1 to 11 according to the first embodiment, except that the oxidized shrink layer 106 is provided in both the second reflector 102 and the first reflector 102. Note that the oxidized shrink layer 106 may be provided in both the second cladding layer 105 and the first cladding layer 103.

[0345] (Surface emitting laser according to sixth modification example of first embodiment of the present technology)

[0346] Fig.46 A is a cross-sectional view (part 1) of a surface emitting laser 10 - M6 according to a sixth modification example of the first embodiment of the present technology. Fig.46 B is a cross-sectional view (part 2) of a surface emitting laser 10 - M6 according to a sixth modification example of the first embodiment of the present technology.

[0347] like Fig.46 A and Fig.46 As shown in FIG. 2B , the surface emitting laser 10 - M6 has a configuration similar to any of the surface emitting lasers 10 - 1 to 10 - 11 according to Embodiments 1 to 11 of the first embodiment, except that a cathode electrode 109 is provided on the back surface (lower surface) of the substrate 101 .

[0348] (Surface emitting laser according to seventh modification example of first embodiment of the present technology)

[0349] Fig.47A is a cross-sectional view (part 1) of a surface emitting laser 10 - M7 according to a seventh modification example of the first embodiment of the present technology. Fig.47 B is a cross-sectional view (part 2) of a surface emitting laser 10 - M7 according to a seventh modification example of the first embodiment of the present technology.

[0350] like Fig.47 A and Fig.47 As shown in FIG. 1B, the surface emitting laser 10-M7 has a configuration similar to that of any one of the surface emitting lasers 10-1 to 10-11 according to Examples 1 to 11 of the first embodiment, but, similar to the surface emitting laser 20-3 according to Example 3 of the second embodiment, an ion implantation region IIA as a high resistance region is provided in the second structure ST2.

[0351] Also in the surface emitting laser 10 - M7 , the ratio of the length D1 in the length direction to the length D2 in the width direction of the inner edge of the ion implantation region IIA is preferably greater than 1.00 and less than or equal to 1.10.

[0352] (Surface emitting laser according to eighth modification example of first embodiment of the present technology)

[0353] Fig.48 A is a cross-sectional view (part 1) of a surface emitting laser 10 - M8 according to an eighth modification example of the first embodiment of the present technology. Fig.48 B is a cross-sectional view (part 2) of a surface emitting laser 10 - M8 according to an eighth modification example of the first embodiment of the present technology.

[0354] like Fig.48 A and Fig.48 As shown in FIG. 1B , the surface emitting laser 10-M8 has a configuration similar to that of any one of the surface emitting lasers 10-1 to 10-11 according to Examples 1 to 11 of the first embodiment, but an anode electrode 108 is provided in a solid shape on the second structure ST2, a cathode electrode 109 is provided in a ring shape on the back side (lower surface) of the substrate 101, and the contact layer 111 is not provided.

[0355] In the surface emitting laser 10-M8, the reflectivity of the second reflector 107 is set to be slightly greater than the reflectivity of the first reflector 102. That is, the surface emitting laser 10-M8 is a back-emitting surface emitting laser that emits light to the back side (lower surface side) of the substrate 101. Note that in the surface emitting laser 10-M8, a highly doped semiconductor layer (e.g., a highly doped GaAs layer) as a contact layer may be provided between the second reflector 107 and the anode electrode 108 and / or between the substrate 101 and the cathode electrode.

[0356] (Surface-emitting laser array according to ninth modification of first embodiment of the present technology)

[0357] Fig.49 A is a cross-sectional view (part 1) of a surface emitting laser array 10 - M9 according to a ninth modification example of the first embodiment of the present technology. Fig.49 B is a cross-sectional view (part 2) of a surface emitting laser array 10 - M9 according to a ninth modification example of the first embodiment of the present technology. Fig.50 is a plan view of a surface emitting laser array 10 - M9 according to a ninth modification example of the first embodiment of the present technology. Fig.49 A is along Fig.50 A cross-sectional view taken along line 49A-49A in FIG. Fig.49 B is along Fig.50 A cross-sectional view taken along line 49B-49B in FIG.

[0358] like Fig.49 A. Fig.49 B and Fig.40 As shown in FIG. 1 , a surface emitting laser array 10 - M9 includes a plurality of (eg, four) surface emitting lasers 10 - 1 arranged in a two-dimensional array (eg, a matrix arrangement). In the surface emitting laser array 10 - M9 , a first structure ST1 of each of the surface emitting lasers 10 - 1 shares a substrate 101 .

[0359] The number and arrangement of the surface emitting lasers 10-1 in the surface emitting laser array 10-M9 may be appropriately changed. For example, the number of the surface emitting lasers 10-1 may be 2, 3, or 5 or more. The arrangement of the plurality of surface emitting lasers 10-1 may be a one-dimensional arrangement. The plurality of surface emitting lasers 10-2 to 10-11 and 10-M1 to 10-M8 may be arranged in one dimension or two dimensions to form a surface emitting laser array.

[0360] (Surface emitting laser according to first modified example of second embodiment of the present technology)

[0361] Fig.51 is a cross-sectional view (part 1) of a surface emitting laser 20 - M1 according to a first modification example of the second embodiment of the present technology. Fig.52 is a cross-sectional view (part 2) of a surface emitting laser 20 - M1 according to a first modification example of the second embodiment of the present technology. Fig.53 is a plan view of a surface emitting laser 20 - M1 according to a first modification example of the second embodiment of the present technology. Fig.51 It is along Fig.53 A cross-sectional view taken along line 51-51 in FIG. Fig.52 It is along Fig.53 A cross-sectional view taken along line 52-52 in FIG.

[0362] <<Configuration of surface emitting laser>>

[0363] like Figure 51 to Figure 53 As shown in , the surface emitting laser 20 - M1 has a configuration substantially similar to that of the surface emitting laser 20 - 3 according to Example 3 of the second embodiment, except that the second structure ST2 is not a mesa structure.

[0364] In the surface emitting laser 20-M1, for example, Fig.53 As shown in FIG. 1 , a plurality of (e.g., six) grooves T1 (recesses) are provided to be separated (e.g., at substantially equal intervals) along the outer periphery of the second structure ST2 having an elliptical shape in a plan view. Each groove T1 exists in an annular virtual area AR ( Fig.53 The inner peripheral surface of the groove T1 constitutes a part of the outer peripheral surface of the second structure ST2. Note that the number and shape of the grooves T1 can be changed appropriately.

[0365] In the surface emitting laser 20-M1, two trenches T1 are provided so as to sandwich the second structure ST2 in the length direction Ld2 (see Fig.51 and Fig.53 ). That is, the length D of the second structure ST2 in the length direction Ld2 is L2 The second structure ST2 is defined by the inner peripheral surfaces of the two grooves T1 facing each other in the length direction Ld2. Furthermore, in the surface emitting laser 20-M1, the two grooves T1 are provided so as to sandwich the second structure ST2 in each of the two directions intersecting the length direction Ld2 and the width direction Sd2 and intersecting each other (see Fig.53 ).

[0366] The inner edge IIAa of the ion implantation region IIA is, for example, elliptical in plan view. In the inner edge IIAa, the major axis direction coincides with the length direction Ld2, and the minor axis direction coincides with the width direction Sd2. The major axis length IDL and the minor axis length IDS (=D S2 ) is preferably greater than 1.00 and less than 1.10. The refractive index of the ion implantation area IIA is lower than the refractive index of the area on the inner diameter side (non-ion implantation area), which has an optical confinement effect. Since the inner edge IIAa of the ion implantation area IIA has shape anisotropy in the long side direction and the short side direction when viewed from above, anisotropy appears in the refractive index distribution, and the width direction mode can be further stabilized. As ion species used for the ion implantation area IIA, H and B can be listed.

[0367] In the surface emitting laser 20 - M1 , the length D of the second structure ST2 in the width direction Sd2 is S2 The inner edge IIAa of the ion implantation region IIA is defined (see Fig.52 and Fig.53 ). That is, the length D of the second structure ST2 in the width direction Sd2 is S2 It is consistent with the minor axis length IDS of the inner edge IIAa of the ion implantation region IIA.

[0368] In the surface emitting laser 20-M1, the first ratio r1 (D L1 / D S1 ) and the second ratio rr2(D L2 / D S2 ) preferably has a value similar to that of the surface emitting laser 10-1 according to Example 1 of the first embodiment.

[0369] The ratio ro of the major axis length to the minor axis length of the outer edge ARo of the annular region AR is preferably 1.00 or more and 1.10 or less.

[0370] The ratio ri of the major axis length to the minor axis length of the inner edge ARi of the annular region AR is preferably 1.05 or more and 1.50 or less.

[0371] In particular, it is preferred that ri>ro. Therefore, in the second structure ST2, different stresses are generated in the length direction and the width direction (specifically, a greater stress is generated in the length direction than in the width direction), and an effect of promoting the asymmetry of the oxidation shrinkage layer 106 can be obtained.

[0372] Here, the first portion 112a of the low dielectric constant region 112A may not be provided in each trench T1 (see Fig.51 ), but the first portion 112a of the low dielectric constant region 112A may be provided. The second portion 112b of the low dielectric constant region 112A does not have a surrounding portion (see Fig.52 ), but may have a surrounding portion.

[0373] <<Method for manufacturing a surface emitting laser>>

[0374] In the following, reference will be made to Fig.54 Flowchart and Fig.55 A to Fig.60 The cross-sectional view of B describes a method for manufacturing the surface emitting laser 20 - M1 . Fig.55 A to Fig.60 B corresponds to the Fig.53 A cross-sectional view of a section taken along line 51 - 51 in FIG.

[0375] Here, as an embodiment, by a semiconductor manufacturing method using a semiconductor manufacturing apparatus, a plurality of surface emitting lasers 20-M1 are simultaneously generated on one wafer (hereinafter, for convenience, also referred to as "substrate 101") as a base material of a substrate 101. Next, a plurality of continuous and integrated surface emitting lasers 20-M1 are separated from each other to obtain a plurality of chip-shaped surface emitting lasers 20-M1.

[0376] In a first step S31, a multilayer body is generated (see Fig.55 A). Specifically, for example, a first reflector 102, a first cladding layer 103, an active layer 104, a second cladding layer 105, a second reflector 107, the second reflector 107 having an oxide layer 106S (for example, an AlAs layer or an AlGaAs layer as a material of the oxide shrinkage layer 106 is provided), and a contact layer 111 is stacked in this order (for example, a substrate 101 (for example, an n-GaAs substrate) is formed by a metal organic chemical vapor deposition (MOCVD) method at a growth temperature of 605°C on the substrate 101 as a growth substrate. It should be noted that when MOCVD is performed, for example, trimethylgallium ((CH3)3Ga) is used as a source gas for gallium, for example, trimethylaluminum ((CH3)3Al) is used as a source gas for aluminum, for example, trimethylindium ((CH3)3In) is used as a source gas for indium, and for example, trimethylarsenic (((CH3)3As) is used as a source gas for As. In addition, as a raw material gas for silicon, for example, monosilane (SiH4) is used, and as a raw material gas for carbon, for example, carbon tetrabromide (CBr4) is used.

[0377] In the next step S32, an ion implantation region IIA is formed (see Fig.55 B). That is, a resist pattern is formed on the upper surface of the multilayer body (the surface on the contact layer 111 side) to cover the area other than the area where the ion implantation area IIA is to be formed, and ion implantation is performed using the resist pattern as a mask. The implantation depth of the ion implantation at this time is set to, for example, a degree that the ions reach the inside of the first reflector 102.

[0378] In the next step S33, a separation groove 101a is formed (see Fig.56 A). The separation groove 101a is a groove for separating adjacent surface emitting lasers 20-M1 generated on a wafer by cutting. First, a resist pattern covering a portion on the upper surface of the multilayer body except for a portion where the separation groove 101a is to be formed is formed by photolithography. Next, the multilayer body is etched by dry etching using, for example, Cl2, SiCl4 or Ar using the resist pattern as a mask. The etching depth at this time is set to a level until the etching bottom surface is located in the substrate 101. Thereafter, the resist pattern is removed by etching.

[0379] In the next step S34, trenches T1 and T2 are formed. Specifically, first, a resist pattern is formed by photolithography to cover the portion of the upper surface of the multilayer body except for the portion where the trench T2 is to be formed. Next, the multilayer body is etched using, for example, Cl2, SiCl4, or Ar inductively coupled plasma (ICP) dry etching using the resist pattern as a mask until the bottom surface of the etching reaches the upper surface of the substrate 101, so as to form a circular trench T2 in a top view. Next, the resist pattern (see FIG. 1 ) is removed. Fig.56 B). Next, a resist pattern is formed by photolithography to cover the portion of the upper surface of the multilayer body except for the portion where the groove T1 is to be formed. Next, using the resist pattern as a mask, the multilayer body is etched by inductively coupled plasma (ICP) dry etching using, for example, Cl2, SiCl4, or Ar, until the etching bottom surface is located in the first reflector 102, and a plurality of (for example, six) grooves T1 having an arc shape in a plan view are formed. Thus, a second structure ST2 having an elliptical shape (for example, an elliptical shape with a major axis length of 22 μm and a minor axis length of 20 μm) in a plan view with the inner circumferential surface of the groove T1 as a part of the outer circumferential surface is formed. Next, the resist pattern (see Fig.57 A). Note that the trench T2 may be formed after forming each trench T1.

[0380] In the next step S35, an oxidized shrink layer 106 is formed as an optical confinement layer (see Fig.57 B). Specifically, the second structure ST2 having an elliptical shape in a plan view formed in step S34 is exposed to a high-temperature water vapor atmosphere, and the oxide layer 106S is oxidized by a predetermined distance (for example, 6.75 μm) from the outer peripheral side toward the center side. As a result, an oxidized shrinkage layer 106 is formed in which an unoxidized region having an elliptical shape in a plan view (for example, an ellipse having a major axis length of 8.5 μm and a minor axis length of 6.5 μm) is surrounded by an oxidized region as a low refractive index region 106b.

[0381] In the next step S36, a thin insulating film 110 (see Fig.58 ).

[0382] In the next step S37, the second portion 112b of the low dielectric constant region 112A is formed (see Fig.52 ). Specifically, first, a thick film of BCB, which is a low dielectric constant material, is formed on the entire surface. Next, unnecessary portions of the BCB film are removed by photolithography and etching. Thus, the second portion 112b is formed.

[0383] In the next step S38, an insulating film 113 (see Fig.52 Specifically, first, the insulating film 113 is formed on the entire surface. Next, the insulating film 113 other than the insulating film 113 covering the second portion 112b of the low dielectric constant region 112A is removed by photolithography and etching.

[0384] In the next step S39, the anode electrode 108 and the first cathode electrode 109A1 are formed. Specifically, first, a portion of the insulating film 110 is removed by photolithography and etching to form a ring-shaped contact hole CHa in a plan view and a contact hole CHc for mounting the first cathode electrode 109A1 (see FIG. Fig.59 A). Next, for example, by lift-off method, an anode electrode 108 is formed in the contact hole CHa so that the electrode portion 108a has a ring shape (for example, an inner diameter of 12.6 μm and an outer diameter of 18.0 μm), and a first cathode electrode 109A1 is formed in the contact hole CHc (see Fig.59 B) To form the electrode materials of the anode electrode 108 and the first cathode electrode 109A1, for example, vacuum evaporation, sputtering, etc. are used.

[0385] In the next step S40, an insulating film 115 (see Fig.60 A). Specifically, first, the insulating film 115 is formed on the entire surface. Next, at least the insulating film 115 covering the pad 108b of the anode electrode 108 and the insulating film 115 covering the pad 109A2 of the first cathode electrode 109A are removed by photolithography and etching (see Fig.53 ).

[0386] In the next step S41, a second cathode electrode 109B (see Fig.60 B) Specifically, the second cathode electrode 109B is formed in a solid shape on the back surface of the substrate 101 by, for example, a lift-off method. At this time, for example, a film of an electrode material of the second cathode electrode 109B is formed using vacuum deposition, sputtering, or the like.

[0387] <<Effects of Surface Emitting Lasers>>

[0388] According to the surface emitting laser 20 - M1 , effects substantially similar to those of the surface emitting laser 20 - 3 according to Example 3 of the second embodiment can be obtained.

[0389] It should be noted that in the surface emitting laser 20 - M1 , the length D in the length direction Ld2 of the second structure ST2 L2 The length D of the second structure ST2 in the width direction Sd2 may be defined by the inner edge IIAa of the ion implantation region IIA. S2 It may be defined by inner peripheral surfaces of two trenches T1 facing each other.

[0390] In the surface emitting laser 20 - M1 , the length D of the second structure ST2 in the length direction Ld2 is L2 and the length D in the width direction Sd2 S2 Each of the trenches T1 may be defined by inner peripheral surfaces of the two trenches T1 facing each other. In this case, the ion implantation region IIA may not be provided.

[0391] (Surface emitting laser according to second modification example of second embodiment of the present technology)

[0392] Fig.61 is a cross-sectional view (part 1) of a surface emitting laser 20 - M2 according to a second modification example of the second embodiment of the present technology. Fig.62 is a cross-sectional view (part 2) of a surface emitting laser 20 - M2 according to a second modification example of the second embodiment of the present technology. Fig.63 is a plan view of a surface emitting laser 20 - M2 according to a second modification example of the second embodiment of the present technology. Fig.61 It is along Fig.63 A cross-sectional view taken along line 61-61 in FIG. Fig.62 It is along Fig.63 A cross-sectional view taken along line 62-62 in FIG.

[0393] like Figure 61 to Figure 63 As shown in , the surface emitting laser 20 - M2 has a configuration basically similar to that of the surface emitting laser 20 - M1 according to the first modification example of the second embodiment, however, the trench T1 (groove) is not provided.

[0394] In the surface emitting laser 20-M2, the length D of the second structure ST2 in the length direction Ld2 is L2 and the length D in the width direction Sd2 S2 The inner edge IIAa of the ion implantation region IIA is defined (see Fig.61 , Fig.62 as well as Fig.63 ). That is, the length D of the second structure ST2 in the length direction Ld2 is L2 The length D of the second structure ST2 in the width direction Sd2 is consistent with the major axis length IDL of the inner edge IIAa of the ion implantation region IIA. S2 It is consistent with the minor axis length IDS of the inner edge IIAa of the ion implantation region IIA.

[0395] In the surface emitting laser 20-M2, the first ratio r1 (D L1 / D S1 ) and the second ratio rr2(D L2 / D S2) preferably has a value similar to that of the surface emitting laser 10-1 according to Example 1 of the first embodiment.

[0396] The surface emitting laser 20 - M2 can be manufactured by a manufacturing method similar to the method for manufacturing the surface emitting laser 20 - M1 according to the first modification example, except that the trench T1 is not formed.

[0397] According to the surface emitting laser 20 - M2 , it is possible to obtain effects substantially similar to those of the surface emitting laser 20 - M1 according to the first modification.

[0398] (Surface emitting laser according to third modification example of second embodiment of the present technology)

[0399] Fig.64 is a plan view of a surface emitting laser 20 - M3 according to a third modification example of the second embodiment of the present technology.

[0400] like Fig.64 As shown in FIG. 1 , the surface emitting laser 20 - M3 has a configuration similar to that of the surface emitting laser 20 - 3 according to Example 3 of the second embodiment, but the length direction and the width direction of the second structure ST2 do not coincide with the crystal direction CO of the substrate 101 in a plan view.

[0401] In the surface emitting laser 20-M3, in a plan view, the length direction Ld2 of the mesa structure as the second structure ST2 and the length direction Ld1 of the high refractive index region 106a are rotated (tilted) by an angle θ (0<θ≤90°) relative to the crystal direction CO of the substrate 101. In other words, in the surface emitting laser 20-M3, in a plan view, the side direction Sd2 of the mesa structure as the second structure ST2 and the side direction Sd1 of the high refractive index region 106a are rotated (tilted) by an angle (90°-θ) relative to the crystal direction CO of the substrate 101.

[0402] Fig.65 : is a graph illustrating the relationship between the mesa rotation angle (θ) of the mesa structure as the second structure ST2 and the relative intensity noise (RIN) in a plan view, the mesa rotation angle (θ) being the rotation angle with respect to the crystal direction CO. Fig.65 It can be seen that, compared with the case where the table rotation angle (θ) is 0° (the minimum value is 45°), the RIN is smaller when the table rotation angle (θ) is greater than 0° in the range of 0° to 90°. Therefore, in the surface emitting laser 20-M3, since 0<θ≤90°, the RIN can be made smaller than the RIN in the case of θ=0.

[0403] Furthermore, in the surface emitting lasers 20-1 and 20-2 according to Examples 1 and 2 of the second embodiment and the surface emitting lasers 20-M1 and 20-M2 according to the first and second modifications of the second embodiment, similarly to the surface emitting laser 20-M3, 0<θ≤90° can be set. Therefore, RIN can be reduced.

[0404] (Other Modifications of the Present Technology)

[0405] The present technology may also include the following variations.

[0406] For example, the surface emitting laser according to the present technology is a GaAs-based surface emitting laser, but in short, a III-V compound main conductor can be used as a material. For example, the present technology can also be applied to an InP-based surface emitting laser and a GaN-based surface emitting laser.

[0407] The optical confinement layer of the surface emitting laser according to the present technology is not limited to the oxidized confinement layer, and for example, a normal layer in which a high refractive index region (such as a buried tunnel junction (BTJ)) or a layer in which a semiconductor is surrounded by a dielectric having a refractive index lower than that of the semiconductor (e.g., SiO2) is surrounded by a low refractive index region can be used.

[0408] The high resistance region of the surface emitting laser according to the present technology is not limited to the ion implantation region and may be, for example, a QWI, a buried tunnel junction, etc., which provides a band gap energy difference between the inside and outside of the opening by Ga hole diffusion to confine carriers.

[0409] The material of the low dielectric constant region of the surface emitting laser according to the present technology is not limited to BCB, and may be polyimide or the like.

[0410] For example, at least one of the first reflector and the second reflector of the surface emitting laser according to the present technology may include a plurality of component layers including different materials and stacked on each other. Specifically, the first reflector and the second reflector may be a hybrid mirror including a semiconductor multilayer film reflector and a dielectric multilayer film reflector, a hybrid mirror including a semiconductor multilayer film reflector and a metal reflector, a hybrid mirror including a dielectric multilayer film reflector and a metal reflector, or a hybrid mirror including a semiconductor multilayer film reflector, a dielectric multilayer film reflector and a metal reflector.

[0411] For example, the substrate 101 may be a Si substrate, a Ge substrate, a GaN substrate, an InP substrate, etc. In any case, it is preferable to appropriately select the semiconductor layer stacked on the substrate 101 so as to lattice match the material of the substrate 101. The surface emitting laser according to the present technology can use a material having any oscillation wavelength included in a wavelength band of 200 nm to 2000 nm.

[0412] In the surface emitting laser according to each of the above embodiments and modifications, the contact layer 111 is not essential.

[0413] The conductivity types (n type and p type) of the first structure ST1 and the second structure ST2 of the surface emitting laser of the above embodiment and modification examples are interchangeable.

[0414] Some configurations of the surface emitting lasers of the above-described embodiments and modifications may be combined within the range that they do not conflict with each other.

[0415] In the above-described embodiments and modifications, the material, conductivity type, thickness, width, value, shape, size, etc. of each layer constituting the surface emitting laser can be appropriately changed within the range of use as a surface emitting laser.

[0416] Furthermore, the present technology can also adopt the following configurations.

[0417] (1) A surface emitting laser comprising:

[0418] A first structure includes a substrate; and

[0419] The second structure is arranged on the first structure, wherein:

[0420] The second structure includes:

[0421] at least a portion of a first reflector;

[0422] a second reflector stacked with the first reflector;

[0423] an active layer disposed between the first reflector and the second reflector; and

[0424] an optical confinement layer arranged between a surface of the first reflector on a side opposite to the active layer and the active layer, and / or between a surface of the second reflector on a side opposite to the active layer and the active layer,

[0425] The optical confinement layer has a high refractive index region with a relatively high refractive index and a low refractive index region with a relatively low refractive index surrounding the high refractive index region,

[0426] Each of the second structure and the high refractive index region has a length direction and a width direction in a plan view,

[0427] The first ratio is a ratio of the length of the high refractive index region in the length direction to the length in the width direction, and the second ratio is a ratio of the length of the second structure in the length direction to the length in the width direction, both of which are greater than 1.00 and less than 2.00, and

[0428] The first ratio is greater than the second ratio.

[0429] (2) The surface emitting laser according to (1), wherein the first ratio is 1.75 or less.

[0430] (3) The surface emitting laser according to (1) or (2), wherein the first ratio is 1.15 or more.

[0431] (4) The surface emitting laser according to any one of (1) to (3), wherein the first ratio is 1.15 or more and 1.75 or less.

[0432] (5) The surface emitting laser according to any one of (1) to (4), wherein the second ratio is 1.50 or less.

[0433] (6) The surface emitting laser according to any one of (1) to (5), wherein the second ratio is 1.05 or more.

[0434] (7) The surface emitting laser according to any one of (1) to (6), wherein the second ratio is 1.05 or more and 1.50 or less.

[0435] (8) The surface emitting laser according to any one of (1) to (7), wherein the high refractive index region has a symmetrical shape with respect to each of a length direction and a width direction of the high refractive index region in a plan view.

[0436] (9) The surface emitting laser according to any one of (1) to (8), wherein the second structure has a symmetrical shape with respect to each of a length direction and a width direction of the second structure in a plan view.

[0437] (10) The surface emitting laser according to any one of (1) to (9), wherein a length direction or a width direction of the second structure is parallel to a crystal direction <0 1 -1> of the substrate.

[0438] (11) The surface emitting laser according to any one of (1) to (10), wherein an area centroid of the second structure and an area centroid of the high refractive index region do not coincide with each other.

[0439] (12) A surface emitting laser according to any one of (1) to (11), wherein the first offset is greater than the second offset, the first offset being an offset of the area centroid of the second structure and the high refractive index region in the length direction of the second structure, and the second offset being an offset of the area centroid of the second structure and the high refractive index region in the width direction of the second structure.

[0440] (13) The surface emitting laser according to (12), wherein the first shift amount is 0.20 μm or more and the second shift amount is 0.10 μm or less.

[0441] (14) The surface emitting laser according to any one of (1) to (13), wherein a cross section of the second structure does not have a straight line portion and / or a top portion.

[0442] (15) The surface emitting laser according to any one of (1) to (14), wherein an angle formed by the second structure and the high refractive index region in the length direction in a plan view is 10° or less.

[0443] (16) The surface emitting laser according to any one of (1) to (15), wherein a high resistance region surrounding the high refractive index region is provided in the second structure and / or the first structure.

[0444] (17) The inner edge of the high resistance region may have a length direction and a width direction in a plan view, and a ratio of a length in the length direction of the inner edge to a length in the width direction may be greater than 1.00 and less than or equal to 1.10.

[0445] (18) The surface emitting laser according to any one of (1) to (17), further comprising: a low dielectric constant region surrounding the second structure.

[0446] (19) A surface emitting laser according to (18), wherein the low dielectric constant region includes: a first portion having a circumferential shape surrounding the second structure; and a second portion having a surrounding portion arranged on the second structure, an inner edge of the surrounding portion having a length direction and a width direction in a plan view, and a ratio of a length of the inner edge in the length direction to a length in the width direction is greater than 1.00 and less than or equal to 1.10.

[0447] (20) The surface emitting laser according to any one of (1) to (19), wherein the optical confinement layer is an oxidized shrinkage layer.

[0448] (21) The surface emitting laser according to any one of (1) to (20), wherein the second structure is a mesa structure.

[0449] (22) A surface emitting laser according to any one of (1) to (20), wherein each of the first structure and the second structure is part of a stacked structure, and a length of the second structure in a length direction and / or a length in a width direction is defined by a plurality of grooves provided in the stacked structure.

[0450] (23) A surface emitting laser according to any one of (1) to (20), wherein each of the first structure and the second structure is part of a stacked structure, and a length of the second structure in a length direction and / or a length in a width direction is defined by an inner edge of an ion implantation region provided in the stacked structure.

[0451] (24) The surface emitting laser according to any one of (1) to (23), wherein a length direction and a width direction of the second structure in a plan view do not coincide with a crystal orientation of the substrate.

[0452] (25) A surface emitting laser array comprising a plurality of surface emitting lasers according to any one of (1) to (24).

[0453] (26) An electronic device comprising the surface emitting laser according to any one of (1) to (24).

[0454] (27) An electronic device comprising the surface emitting laser array according to (25).

[0455] Reference Symbols List

[0456] 10-1 to 10-11, 20-1 to 20-3, 10-M1 to 10-M8 surface emitting lasers

[0457] 101 substrate

[0458] 102 First reflector

[0459] 104 Active layer

[0460] 106 Oxidation shrinkage layer (optical confinement layer)

[0461] 106a High refractive index region

[0462] 106b Low refractive index region

[0463] 107 Second reflector

[0464] 108 Anode electrode

[0465] 109 cathode electrode

[0466] 112 Low dielectric constant region

[0467] ST1 First Structure

[0468] ST2 Second structure

[0469] D Ll The length of the high refractive index region in the longitudinal direction

[0470] D S1 The length of the high refractive index region in the width direction

[0471] D L2 The length of the second structure ST2 in the longitudinal direction

[0472] D S2 The length of the second structure ST2 in the width direction

[0473] IIA ion implantation region (high resistance region).

Claims

1. A surface emitting laser comprising: A first structure includes a substrate; as well as The second structure is arranged on the first structure, wherein: The second structure comprises: at least a portion of a first reflector; a second reflector, stacked with the first reflector; an active layer disposed between the first reflector and the second reflector; and an optical confinement layer disposed between a surface of the first reflector on a side opposite to a side of the active layer and the active layer, and / or disposed between a surface of the second reflector on a side opposite to a side of the active layer and the active layer, The optical confinement layer has a high refractive index region with a relatively high refractive index and a low refractive index region with a relatively low refractive index surrounding the high refractive index region, Each of the second structure and the high refractive index region has a length direction and a width direction in a plan view, The first ratio is a ratio of the length of the high refractive index region in the length direction to the length in the width direction, and the second ratio is a ratio of the length of the second structure in the length direction to the length in the width direction, both of which are greater than 1.00 and less than 2.00, and The first ratio is greater than the second ratio.

2. The surface emitting laser according to claim 1, wherein The first ratio is 1.75 or less.

3. The surface emitting laser according to claim 1, wherein The first ratio is greater than or equal to 1.

15.

4. The surface emitting laser according to claim 1, wherein The first ratio is greater than or equal to 1.15 and less than or equal to 1.

75.

5. The surface emitting laser according to claim 1, wherein The second ratio is 1.50 or less.

6. The surface emitting laser according to claim 1, wherein The second ratio is 1.05 or more.

7. The surface emitting laser according to claim 1, wherein The second ratio is 1.05 or more and 1.50 or less.

8. The surface emitting laser according to claim 1, wherein The high refractive index region has a symmetrical shape with respect to each of a length direction and a width direction of the high refractive index region in a plan view.

9. The surface emitting laser according to claim 1, wherein The second structure has a symmetrical shape with respect to each of a length direction and a width direction of the second structure in a plan view.

10. The surface emitting laser according to claim 1, wherein The length direction or the width direction of the second structure extends in a direction along the crystal direction <0 1-1> of the substrate.

11. The surface emitting laser according to claim 1, wherein The area centroid of the second structure and the area centroid of the high refractive index region do not coincide with each other.

12. The surface emitting laser according to claim 11, wherein The first offset is greater than the second offset, the first offset being the offset of the area centroid of the second structure and the high refractive index region in the length direction of the second structure, and the second offset being the offset of the area centroid of the second structure and the high refractive index region in the width direction of the second structure.

13. The surface emitting laser according to claim 12, wherein The first offset amount is greater than or equal to 0.20 μm, and the second offset amount is less than or equal to 0.10 μm.

14. The surface emitting laser according to claim 1, wherein The cross-section of the second structure has no straight portion and / or top portion.

15. The surface emitting laser according to claim 1, wherein An angle formed by the second structure and the high refractive index region in the length direction in a plan view is 10° or less.

16. The surface emitting laser according to claim 1, wherein A high resistance region surrounding the high refractive index region is provided in the second structure and / or the first structure.

17. The surface emitting laser according to claim 16, wherein The inner edge of the high resistance region has a length direction and a width direction in a plan view, and A ratio of the length of the inner edge in the length direction to the length of the inner edge in the width direction is greater than 1.00 and less than or equal to 1.

10.

18. The surface emitting laser according to claim 1, further comprising: The low dielectric constant region surrounds the second structure.

19. The surface emitting laser according to claim 18, wherein The low dielectric constant region comprises: a circumferential first portion surrounding the second structure; and a second portion having a surrounding portion disposed on the second structure, The inner edge of the surrounding portion has a length direction and a width direction in a plan view, and A ratio of the length of the inner edge in the length direction to the length of the inner edge in the width direction is greater than 1.00 and less than or equal to 1.

10.

20. The surface emitting laser according to claim 1, wherein The optical confinement layer is an oxidative shrinkage layer.

21. The surface emitting laser according to claim 1, wherein Each of the first structure and the second structure is a part of a stacked structure, and a length of the second structure in a length direction and / or a length in a width direction is defined by a plurality of grooves provided in the stacked structure.

22. The surface emitting laser according to claim 1, wherein Each of the first structure and the second structure is a part of a stacked structure, and a length of the second structure in a length direction and / or a length in a width direction is defined by an inner edge of an ion implantation region provided in the stacked structure.

23. The surface emitting laser according to claim 1, wherein The length direction and the width direction of the second structure in a plan view are not consistent with the crystal orientation of the substrate.

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