Surface-emitting laser, surface-emitting laser array, electronic device, and method of manufacturing surface-emitting laser

Abstract

To provide a surface emission laser, a surface emission laser array in which the surface emission laser is arrayed two-dimensionally, and a surface emission laser manufacturing method, that enable efficient injection of a current to an active layer, while suppressing deterioration of crystallinity of layers stacked above a contact area.SOLUTION: A surface emission laser includes a substrate 100, and a mesa structure formed on the substrate. The mesa structure includes at least a part of a first multilayer film reflector 200a stacked on the substrate, an active layer 200b stacked on the first multilayer film reflector, and a second multilayer film reflector 200c stacked on the active layer. An impurity area is provided over a contact area CA that is adjacent to the mesa structure and contacts an electrode, and a side wall section of a portion of the mesa structure which portion includes the first multilayer film reflector.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology according to the present disclosure (hereinafter also referred to as "the technology") relates to a surface-emitting laser, a surface-emitting laser array, an electronic device, and a method for manufacturing a surface-emitting laser. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a surface-emitting laser having a substrate and a mesa structure formed on the substrate is known. For example, Patent Document 1 discloses a surface-emitting laser in which a contact region adjacent to a mesa structure and in contact with an electrode is heavily doped with impurities. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-223975 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the surface-emitting laser disclosed in Patent Document 1, it was not possible to efficiently inject current into the active layer while suppressing deterioration of the crystallinity of the layers stacked above the contact region (at a position farther from the substrate than the contact region).

[0005] Therefore, the present technology aims to provide a surface-emitting laser that can efficiently inject current into the active layer while suppressing deterioration of the crystallinity of the layers stacked above the contact region, a surface-emitting laser array in which the surface-emitting lasers are arranged two-dimensionally, and a method for manufacturing the surface-emitting laser. [Means for solving the problem]

[0006] The present technology includes a substrate and a mesa structure formed on the substrate; Equipped with The mesa structure includes: at least a portion of a first multilayer film reflector laminated on the substrate; an active layer laminated on the first multilayer film reflector; a second multilayer film reflector laminated on the active layer; and Including, The surface-emitting laser has an impurity region extending across a contact region adjacent to the mesa structure that is in contact with an electrode and a sidewall portion of the mesa structure that is made up of the first multilayer film reflector. The impurity region may be continuous from the contact region to the sidewall portion. The mesa structure may include the entire first multilayer reflector, and the contact region may include a portion of the substrate. The mesa structure may include a portion of the first multilayer reflector other than its bottom, and the contact region may include a portion of the bottom of the first multilayer reflector. The mesa structure may include the entire first multilayer reflector and further include a contact layer disposed between the substrate and the first multilayer reflector, and the contact region may include a portion of the contact layer. The contact region may include a portion of the substrate. The contact layer may have a thickness of 1 μm or less. The impurity concentration of the impurity region is 5×10 19 cm -3 It may be less than. Another electrode may be in contact with the surface of the mesa structure on the same side as the electrode with respect to the contact region. The substrate may be a semi-insulating substrate or a lightly doped substrate. The surface-emitting laser may emit light toward the opposite side of the substrate from the mesa structure side. The surface-emitting laser may use an AlGaAs-based compound semiconductor or a GaN-based compound semiconductor. The surface-emitting laser may further include a current confinement layer disposed between the first multilayer reflector and the second multilayer reflector. At least one of the first and second multilayer reflectors may be a semiconductor multilayer reflector. At least one of the first and second multilayer film reflectors may be a dielectric multilayer film reflector. The present technology also provides a surface-emitting laser array in which the surface-emitting lasers are two-dimensionally arranged. The present technology also provides an electronic device including the surface-emitting laser array. The present technology includes a step of forming a stack by stacking at least a first multilayer reflector, an active layer, and a second multilayer reflector on a substrate in this order; forming a first mesa structure by etching the laminate until at least a part of a side surface of the first multilayer film reflector is exposed; forming an insulating film on the first mesa structure and an area adjacent to the first mesa structure; removing the insulating film formed in the adjacent region; diffusing impurities from the adjacent region to a sidewall portion of the first mesa structure that is configured as the first multilayer film reflector; a step of forming a second mesa structure in place of the first mesa structure by etching the laminate until at least another portion of the side surface of the first multilayer film reflector is exposed; providing an electrode on a region adjacent to the second mesa structure; Also provided is a method for manufacturing a surface-emitting laser, including: In the step of producing the laminate, a contact layer may be laminated on the substrate before laminating the first multilayer film reflector, and in the step of forming the second mesa structure, the laminate on which the first mesa structure is formed may be etched until at least the contact layer is exposed. The present technology includes a step of forming a stack by stacking at least a first multilayer reflector, an active layer, and a second multilayer reflector on a substrate in this order; forming a mesa structure by etching the laminate until at least a part of a side surface of the first multilayer film reflector is exposed; forming an insulating film on the mesa structure and an area adjacent to the mesa structure; removing the insulating film formed in the adjacent region; diffusing impurities from the adjacent region to a sidewall portion of the mesa structure that is configured by the first multilayer film reflector; providing an electrode on the adjacent region; Also provided is a method for manufacturing a surface-emitting laser, including: In the step of producing the laminate, a contact layer may be laminated on the substrate before laminating the first multilayer film reflector, and in the step of forming the mesa structure, the laminate may be etched until at least the contact layer is exposed. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view showing a configuration example of a surface-emitting laser according to a first embodiment of the present technology. [Figure 2] 5 is a first half of a flowchart for explaining a first example of a method for manufacturing a surface-emitting laser according to a first embodiment of the present technology. [Figure 3] 10 is a second half of a flowchart for explaining a first example of a method for manufacturing a surface-emitting laser according to the first embodiment of the present technology. [Figure 4] 3A to 3C are cross-sectional views (part 1) of each step of a first example of a manufacturing method for a surface-emitting laser according to a first embodiment of the present technology. [Figure 5] 5A to 5C are cross-sectional views (part 2) of each step of the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 6] 5A to 5C are cross-sectional views (part 3) of each step of the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 7] 6A to 6C are cross-sectional views (part 4) of each step of the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 8] 5A to 5C are cross-sectional views (part 5) of each step of the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 9]6A to 6C are cross-sectional views (part 6) of each step of the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 10] 7A to 7C are cross-sectional views (part 7) of each step of the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 11] 8A to 8C are cross-sectional views (part 8) illustrating steps of the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 12] 9A to 9C are cross-sectional views of each step of the first example of the manufacturing method for the surface-emitting laser according to the first embodiment of the present technology; [Figure 13] 10A to 10C are cross-sectional views of steps in a first example of a method for manufacturing a surface-emitting laser according to a first embodiment of the present technology; [Figure 14] 11A to 11C are cross-sectional views of steps in the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 15] 12A to 12C are cross-sectional views of steps in the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 16] 13A to 13C are cross-sectional views of steps in the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 17] 14A to 14C are cross-sectional views of the steps of the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 18] 15A to 15C are cross-sectional views of steps in the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 19] 16A to 16C are cross-sectional views of steps in the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 20] 17A to 17C are cross-sectional views of steps in the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 21] 18A to 18C are cross-sectional views of steps in the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 22]19A to 19C are cross-sectional views of steps in the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 23] 20A to 20C are cross-sectional views of each step of the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 24] 21A to 21C are cross-sectional views of each step of the first example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 25] 10 is a first half of a flowchart illustrating a second example of a method for manufacturing a surface-emitting laser according to the first embodiment of the present technology. [Figure 26] 10 is a second half of a flowchart for explaining a second example of the method for manufacturing a surface-emitting laser according to the first embodiment of the present technology. [Figure 27] 5A to 5C are cross-sectional views (part 1) of each step of a second example of a method for manufacturing a surface-emitting laser according to the first embodiment of the present technology. [Figure 28] 6A to 6C are cross-sectional views (part 2) of each process of the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 29] 6A to 6C are cross-sectional views (part 3) of each process of the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 30] 6A to 6C are cross-sectional views (part 4) of each step of the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 31] 5A to 5C are cross-sectional views (part 5) illustrating steps of the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 32] 6A to 6C are cross-sectional views (part 6) illustrating steps of the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 33] 7A to 7C are cross-sectional views (part 7) illustrating steps of the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 34] 8A to 8C are cross-sectional views (part 8) illustrating steps of the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 35]9A to 9C are cross-sectional views of each step of the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 36] 10A to 10C are cross-sectional views of steps in a second example of a method for manufacturing a surface-emitting laser according to a first embodiment of the present technology; [Figure 37] 11A to 11C are cross-sectional views of steps in a second example of a method for manufacturing a surface-emitting laser according to a first embodiment of the present technology; [Figure 38] 12A to 12C are cross-sectional views of steps in the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 39] 13A to 13C are cross-sectional views of steps in the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 40] 14A to 14C are cross-sectional views (part 14) of each step of the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology. [Figure 41] 15A to 15C are cross-sectional views of steps in the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 42] 16A to 16C are cross-sectional views of steps in the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 43] 17A to 17C are cross-sectional views of steps in the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 44] 18A to 18C are cross-sectional views of steps in the second example of the method for manufacturing the surface-emitting laser according to the first embodiment of the present technology; [Figure 45] 10 is a cross-sectional view showing a configuration example of a surface-emitting laser according to a second embodiment of the present technology. [Figure 46] 10 is a cross-sectional view showing a configuration example of a surface-emitting laser according to a third embodiment of the present technology. [Figure 47] 1 is a cross-sectional view showing a configuration example of a surface-emitting laser according to a first modified example of the first embodiment of the present technology. [Figure 48] 10 is a cross-sectional view showing a configuration example of a surface-emitting laser according to a second modification of the first embodiment of the present technology. FIG. [Figure 49]FIG. 10 is a cross-sectional view showing a configuration example of a surface-emitting laser according to a third modification of the first embodiment of the present technology. DETAILED DESCRIPTION OF THE INVENTION

[0008] Preferred embodiments of the present technology will be described in detail below with reference to the accompanying drawings. Note that in this specification and the drawings, components having substantially the same functional configurations are denoted by the same reference numerals, and redundant description will be omitted. The embodiments described below illustrate typical embodiments of the present technology, and the scope of the present technology should not be interpreted as being narrow. Even when it is described in this specification that the surface-emitting laser, surface-emitting laser array, electronic device, and method for manufacturing a surface-emitting laser according to the present technology each achieve multiple effects, it is sufficient that the surface-emitting laser, surface-emitting laser array, electronic device, and method for manufacturing a surface-emitting laser according to the present technology each achieve at least one effect. The effects described in this specification are merely examples and are not limiting, and other effects may also be achieved.

[0009] The explanation will be given in the following order: 1. Surface-emitting laser according to the first embodiment of the present technology (1) Configuration of a surface-emitting laser according to a first embodiment of the present technology (2) First Example of Method for Manufacturing Surface-Emitting Laser According to First Embodiment of the Present Technology (3) Second Example of Method for Manufacturing Surface-Emitting Laser According to First Embodiment of the Present Technology (4) Operation of the surface-emitting laser according to the first embodiment of the present technology (5) Effects of the surface-emitting laser according to the first embodiment of the present technology 2. Surface-emitting laser according to a second embodiment of the present technology 3. Surface-emitting laser according to a third embodiment of the present technology 4. Modification of surface-emitting laser according to the present technology 5. Example of use of surface-emitting lasers using this technology Application examples for electronic devices

[0010] 1. Surface-emitting laser according to the first embodiment of the present technology Surface-emitting laser configuration 1 is a cross-sectional view showing a configuration example of a surface-emitting laser 10 according to a first embodiment of the present technology. For convenience, the upper side in the cross-sectional views of FIG. 1 and the like will be referred to as the top and the lower side as the bottom in the following description. 1, the surface-emitting laser 10 includes a substrate 100 and a mesa structure 200 formed on the substrate 100. The upper diagram of Fig. 1 is a plan view of a region of the surface-emitting laser 10 corresponding to the mesa structure 200.

[0011] In the following, an example will be described in which a surface-emitting laser array is formed by two-dimensionally arranging a plurality of surface-emitting lasers 10. In this case, at least the substrate 100 is shared among a plurality of surface-emitting lasers 10, and a plurality of mesa structures 200 are two-dimensionally arranged on the common substrate 100.

[0012] For example, the surface-emitting laser 10 emits light to the side of the substrate 100 opposite to the mesa structure 200. That is, for example, the surface-emitting laser 10 is a back-side emission surface-emitting laser that emits laser light to the back side (lower surface side) of the substrate 100.

[0013] The substrate 100 is, for example, a GaAs substrate of a first conductivity type (for example, p-type). Here, since the substrate 100 is located on the emission side of the mesa structure 200 that constitutes the laser resonator as described below, it is preferable that the substrate 100 be a substrate with low light absorption (a substrate that can suppress a decrease in optical output), such as a semi-insulating substrate or a lightly doped substrate (a substrate with a low impurity concentration). A semi-insulating substrate is a substrate made of compound semiconductors such as gallium arsenide or indium phosphide that does not contain impurities (is not doped) and exhibits high resistance (specific resistance: several MΩ / □).Semi-insulating substrates not only have high electron mobility, but also exhibit high resistance, making it possible to suppress leakage current and capacitance to ground. Therefore, it is preferable to use, as the substrate 100, for example, a GaAs substrate of the first conductivity type, particularly a semi-insulating substrate or a lightly doped substrate.

[0014] The mesa structure 200 includes a first multilayer reflector 200a stacked on the substrate 100, an active layer 200b stacked on the first multilayer reflector 200a, and a second multilayer reflector 200c stacked on the active layer 200b. The first multilayer reflector 200a, the active layer 200b, and the second multilayer reflector 200c form a laser cavity. The mesa structure 200 has, for example, a substantially cylindrical shape, but may have other cylindrical shapes such as a substantially elliptical cylindrical shape or a polygonal cylindrical shape.

[0015] The first and second multilayer reflectors 200a and 200c are, for example, semiconductor multilayer reflectors. Multilayer reflectors are also called distributed Bragg reflectors. A semiconductor multilayer reflector, which is a type of multilayer reflector (distributed Bragg reflector), has low light absorption, high reflectivity, and electrical conductivity.

[0016] The first multilayer reflector 200a is, for example, a semiconductor multilayer reflector of a first conductivity type (e.g., p-type) and has a structure in which multiple types (e.g., two types) of semiconductor layers with different refractive indices are alternately stacked with an optical thickness of ¼ wavelength of the oscillation wavelength. Each refractive index layer of the first multilayer reflector 200a is made of an AlGaAs-based compound semiconductor of the first conductivity type (e.g., p-type).

[0017] The active layer 200b has a quantum well structure including a barrier layer and a quantum well layer made of, for example, an AlGaAs-based compound semiconductor. This quantum well structure may be a single quantum well structure (QW structure) or a multiple quantum well structure (MQW structure).

[0018] The second multilayer reflector 200c is, for example, a semiconductor multilayer reflector of a second conductivity type (e.g., n-type) and has a structure in which multiple types (e.g., two types) of semiconductor layers with different refractive indices are alternately stacked with an optical thickness of ¼ wavelength of the oscillation wavelength. Each refractive index layer of the second multilayer reflector 200c is made of an AlGaAs-based compound semiconductor of the second conductivity type (e.g., n-type).

[0019] Furthermore, the mesa structure 200 includes a current confinement layer 200d disposed between the first multilayer reflector 200a and the active layer 200b. The current confinement layer 200d has, for example, a non-oxidized region 200d1 made of AlAs of a first conductivity type (for example, n-type) and an oxidized region 200d2 surrounding the non-oxidized region 200d1 made of an oxide of AlAs (for example, Al2O3).

[0020] The mesa structure 200 and the region adjacent to the mesa structure 200 (the region between adjacent mesa structures 200) are covered, with some exceptions, with a series of insulating films 250. The insulating films 250 are made of, for example, SiO2, SiN, SiON, or the like. A contact hole CH2 is formed in the insulating film 250 on the top of the mesa structure 200 (more specifically, on the top surface of the second multilayer film reflector 200c), and a cathode electrode 300 is provided in the contact hole CH2 so as to contact the top of the mesa structure 200.

[0021] The cathode electrode 300 may have a single layer structure or a multilayer structure. The cathode electrode 300 is made of at least one metal (including alloys) selected from the group consisting of, for example, Au, Ag, Pd, Pt, Ni, Ti, V, W, Cr, Al, Cu, Zn, Sn, and In. When the cathode electrode 300 has a laminated structure, it is made of materials such as Ti / Au, Ti / Al, Ti / Al / Au, Ti / Pt / Au, Ni / Au, Ni / Au / Pt, Ni / Pt, Pd / Pt, Ag / Pd, etc.

[0022] Furthermore, the mesa structure 200 includes, for example, a contact layer 400 made of a GaAs-based material and disposed between the substrate 100 and the first multilayer reflector 200a. The contact layer 400 is shared among multiple surface-emitting lasers 10. The contact layer 400 is located on the emission side of the mesa structure 200 that constitutes the laser resonator. Therefore, the thickness of the contact layer 400 is preferably 1 μm or less, and more preferably 500 nm or less. By making the thickness of the contact layer 400 1 μm or less, it is possible to reduce light absorption in the contact layer 400, and therefore to suppress a decrease in optical output.

[0023] Furthermore, the mesa structure 200 includes, for example, an etching stop layer 500 disposed between the contact layer 400 and the first multilayer reflector 200a. The etching stop layer 500 is shared among multiple surface-emitting lasers 10. The top of the etch stop layer 500 forms the bottom of the mesa structure 200 .

[0024] The region between adjacent mesa structures 200 on the substrate 100 (the portion adjacent to the mesa structure 200) includes the bottom surface of the contact hole CH1, which is the region not covered with the insulating film 250, and includes a contact region CA in contact with the anode electrode 600. The contact area CA includes a part of the substrate 100 and a part of the contact layer 400 .

[0025] The anode electrode 600 is provided, for example, on the contact region CA, that is, in the contact hole CH1 so as to be in contact with the contact layer 400. The anode electrode 600 is connected to electrode pads (not shown) arranged around the surface-emitting laser array by metal wiring 700 patterned along the plurality of mesa structures 200 . The anode electrode 600 may have a single layer structure or a multilayer structure. The anode electrode 600 is made of at least one metal (including alloys) selected from the group consisting of, for example, Au, Ag, Pd, Pt, Ni, Ti, V, W, Cr, Al, Cu, Zn, Sn, and In. When the anode electrode 600 has a laminated structure, it is made of materials such as Ti / Au, Ti / Al, Ti / Al / Au, Ti / Pt / Au, Ni / Au, Ni / Au / Pt, Ni / Pt, Pd / Pt, Ag / Pd, etc.

[0026] The cathode electrode 300 is in contact with the surface of the mesa structure 200 on the same side as the anode electrode 600 with respect to the contact region CA.

[0027] An impurity region 800 (the lightly blackened portion in FIG. 1) is provided across the contact region CA and the sidewall portion 200a1 of the portion of the mesa structure 200 formed by the first multilayer film reflector 200a. In this specification, the term "impurity region" refers to a region (high-concentration impurity region) having a higher impurity concentration than other regions (at least surrounding regions). More specifically, the impurity region 800 includes a contact region CA, a sidewall portion 200a1, and a region between the contact region CA and the sidewall portion 200a1.

[0028] The impurity region 800 is continuous from the contact region CA to the sidewall 200a1. That is, the impurity region 800 includes a current path from the anode electrode 600 to the first multilayer film reflector 200a. As an example, the impurity region 800 is formed continuously over the entire circumferential area of ​​the mesa structure 200. Note that the impurity region 800 may have a discontinuous portion (intermittent portion) in part of the circumferential area of ​​the mesa structure 200. As shown in FIG. 1, the side wall portion 200a1 is preferably a portion outside the region of the mesa structure 200 that forms the optical waveguide of the portion configured by the first multilayer film reflector 200a (the region corresponding to the non-oxidized region 200d1 of the current confinement layer 200d).

[0029] The impurity region 800 is configured to contain a metal such as Zn, or an ion such as beryllium ion. The impurity region 800 is continuous from the contact region CA to the sidewall 200a1. Note that the impurity region 800 may have a discontinuous portion (intermittent portion) between the contact region CA and the sidewall 200a1. The impurity concentration of the impurity region 800 is 5×10 19 cm -3 Preferably less than 5x10 18 cm -3 It is more preferable that it is less than 10 ... The impurity concentration of the impurity region 800 is preferably approximately uniform throughout the entire impurity region 800, but some variation is acceptable.

[0030] (2) First Example of Method for Manufacturing Surface-Emitting Laser According to First Embodiment of the Present Technology A first example of a method for manufacturing the surface-emitting laser 10 will be described below with reference to FIGS. 2 to 24. FIGS. 2 and 3 are flowcharts for explaining the first example of the method for manufacturing the surface-emitting laser 10. FIGS. 4 to 24 are cross-sectional views (process cross-sectional views) of each step of the first example of the method for manufacturing the surface-emitting laser 10. Here, as an example, a semiconductor manufacturing method is used to simultaneously produce a plurality of surface-emitting laser arrays on a single wafer that is the base material of the substrate 100 (at this time, a plurality of surface-emitting lasers 10 of each surface-emitting laser array are also simultaneously produced). Next, the series of multiple surface-emitting laser arrays are separated from one another to obtain a plurality of chip-shaped surface-emitting laser arrays (surface-emitting laser array chips).

[0031] In the first step S1, a laminate 1000 is produced. Specifically, a contact layer 400, an etching stop layer 500, a first multilayer reflector 200a, a selectively oxidized layer 210, an active layer 200b, and a second multilayer reflector 200c are sequentially stacked on a substrate 100 in this order by chemical vapor deposition (CVD), for example, metal-organic chemical vapor deposition (MOCVD), as shown in FIG.

[0032] In the next step S2, the stacked body 1000 is etched (for example, wet etching) to form the first mesa structure 150. Specifically, as shown in FIG. 5, a resist pattern R1 is formed by photolithography on the laminate 1000 removed from the growth chamber. Next, as shown in FIG. 6, using this resist pattern R1 as a mask, a sulfuric acid-based etchant is used to selectively remove portions of the second multilayer reflector 200c, the active layer 200b, the selectively oxidized layer 210, and the first multilayer reflector 200a. This forms the first mesa structure 150. This etching is performed until the bottom of the etching is positioned within the first multilayer reflector 200a (to a depth where the etching stop layer 500 is not exposed). Thereafter, as shown in FIG. 7, the resist pattern R1 is removed.

[0033] In the next step S3, as shown in FIG. 8, an insulating film 240 made of, for example, SiO 2 is formed on the first mesa structure 150 and an area 350 adjacent thereto. Specifically, the insulating film 240 is formed over substantially the entire area of ​​the stack 1000 in which the first mesa structures 150 are formed. Hereinafter, the region 350 adjacent to the first mesa structure 150 is also referred to as the "adjacent region 350." Here, the adjacent region 350 is located between two adjacent first mesa structures 150 in a plan view.

[0034] In the next step S4, the insulating film 240 formed in the adjacent region 350 is removed. Specifically, as shown in Fig. 9, a resist pattern R2 is formed by photolithography in an area other than an area 350 adjacent to the first mesa structure 150. Next, using this resist pattern R2 as a mask, the insulating film 240 formed in the adjacent area 350 is removed by etching using, for example, a hydrofluoric acid-based etchant, as shown in Fig. 10. Thereafter, the resist pattern R2 is removed as shown in Fig. 11.

[0035] In the next step S5, as shown in FIG. 12, impurities are diffused from the region 350 adjacent to the first mesa structure 150 to form an impurity region 800. Specifically, impurities such as Zn are injected and diffused from the adjacent region 350. For example, the injection rate and time of the impurities are adjusted so that the impurity region 800 diffuses into the first multilayer reflector 200a, the etching stop layer 500, the contact layer 400, and the substrate 100. At this time, the insulating film 240 serves as a mask during the impurity diffusion. For example, if SiO2 is used as the material for the insulating film 240, vacancy diffusion occurs from Ga at the SiO2 interface due to the diffusion, decompression, and heating, making it easier for the impurity to diffuse over a wide area.

[0036] In the next step S6, as shown in FIG. 13, the remaining insulating film 240 is removed. Specifically, the insulating film 240 formed in the region other than the adjacent region 350 is removed using, for example, a hydrofluoric acid-based etchant.

[0037] In the next step S7, the stacked body 1000 is further etched (for example, wet etching) to form a mesa structure 200 which is a second mesa structure replacing the first mesa structure 150. Specifically, as shown in FIG. 14, a resist pattern R3 is formed by photolithography in the region other than the adjacent region 350. Next, using this resist pattern R3 as a mask, the first multilayer film reflector 200a in the adjacent region 350 is selectively removed using, for example, a sulfuric acid-based etchant, as shown in FIG. 15. This forms the mesa structure 200. Thereafter, as shown in FIG. 16, the resist pattern R3 is removed. The etching here is stopped when the etching stop layer 500 is removed and the contact layer 400 is exposed. Hereinafter, the mesa structure 200 will also be referred to as the "second mesa structure 200."

[0038] In the next step S8, as shown in FIG. 17, the peripheral portion of the selectively oxidized layer 210 (see FIG. 16) is oxidized to form a current confinement layer 200d. Specifically, the second mesa structure 200 is exposed to a water vapor atmosphere, and the selectively oxidized layer 210 is oxidized (selectively oxidized) from the side, thereby forming a current confinement layer 200d in which the non-oxidized region 200d1 is surrounded by the oxidized region 200d2.

[0039] In the next step S9, as shown in FIG. 18, an insulating film 250 is formed on the second mesa structure 200 and on the contact region CA adjacent thereto. Specifically, the insulating film 250 is formed over substantially the entire area of ​​the stacked body 1000. Here, the contact region CA is located between two adjacent second mesa structures 200 in plan view.

[0040] In the next step S10, the insulating film 250 on the second mesa structure 200 and on the contact region CA adjacent to the second mesa structure 200 is removed to form a contact hole. Specifically, as shown in Fig. 19, a resist pattern R4 is formed by photolithography in an area other than the contact area CA adjacent to the second mesa structure 200 and the top of the second mesa structure 200. Next, using this resist pattern R4 as a mask, the insulating film 250 on the contact area CA and the insulating film 250 on the top of the second mesa structure 200 are removed by wet etching, as shown in Fig. 20, to form contact holes CH1 and CH2 for electrode contact. Thereafter, as shown in Fig. 21, the resist pattern R4 is removed.

[0041] In the next step S11, as shown in FIG. 22, an anode electrode 600 is provided in the contact region CA adjacent to the second mesa structure 200. Specifically, for example, an Au / Ti film is formed in the contact area CA by EB evaporation, and the resist and the Au / Ti on the resist are lifted off to form the anode electrode 600 in the contact hole CH1.

[0042] In the next step S12, a cathode electrode 300 is provided on the top of the second mesa structure 200, as shown in FIG. Specifically, for example, an Au / Ti film is formed on the top of the second mesa structure 200 by EB evaporation, and the resist and the Au / Ti on the resist are lifted off to form a cathode electrode 300 in the contact hole CH2 on the top of the second mesa structure 200.

[0043] 24, metal wiring 700 is formed to connect the anode electrode 600 provided in the contact region CA adjacent to the second mesa structure 200 to the electrode pad. After that, annealing is performed, the back surface of the wafer (the surface opposite to the surface on the second mesa structure 200 side) is polished to thin the surface, and anti-reflective coating is applied to the back surface of the wafer, thereby forming a plurality of surface-emitting laser arrays in which a plurality of surface-emitting lasers 10 are two-dimensionally arranged on a single wafer. After that, the wafer is separated into a plurality of surface-emitting laser array chips by dicing.

[0044] The order of steps S11 and S12 may be reversed.

[0045] (2) Second Example of Method for Manufacturing Surface-Emitting Laser According to First Embodiment of the Present Technology A second example of a method for manufacturing the surface-emitting laser 10 will be described below with reference to Figs. 25 to 44. Figs. 25 and 26 are flowcharts for explaining the second example of the method for manufacturing the surface-emitting laser 10. Figs. 27 to 44 are cross-sectional views (process cross-sectional views) of each step of the second example of the method for manufacturing the surface-emitting laser 10. Here, as an example, a semiconductor manufacturing method is used to simultaneously produce a plurality of surface-emitting laser arrays on a single wafer, which is the base material of the substrate 100 (at this time, a plurality of surface-emitting lasers 10 in each surface-emitting laser array are also simultaneously produced). Next, the plurality of surface-emitting laser arrays are separated from one another to produce a plurality of chip-shaped surface-emitting laser arrays (surface-emitting laser array chips).

[0046] In the first step S21, a laminate 1000 is produced. Specifically, a contact layer 400, an etching stop layer 500, a first multilayer reflector 200a, a selectively oxidized layer 210, an active layer 200b, and a second multilayer reflector 200c are sequentially stacked on a substrate 100 in this order using a chemical vapor deposition (CVD) method, such as a metal-organic chemical vapor deposition (MOCVD) method, as shown in FIG. 27.

[0047] In the next step S22, the stacked body 1000 is etched (for example, wet etching) to form the mesa structure 200. Specifically, as shown in FIG. 28, a resist pattern R1' is formed by photolithography on the layered product 1000 removed from the growth chamber. Next, as shown in FIG. 29, using this resist pattern R1' as a mask, the second multilayer reflector 200c, the active layer 200b, the selectively oxidized layer 210, and the first multilayer reflector 200a are selectively removed using, for example, a sulfuric acid-based etchant. This forms the mesa structure 200. The etching is stopped when the etching stop layer 500 is removed and the contact layer 400 is exposed. Thereafter, as shown in FIG. 30, the resist pattern R1' is removed.

[0048] 31, an insulating film 240 made of, for example, SiO2 is formed on the mesa structure 200 and on the contact region CA adjacent thereto. Specifically, the insulating film 240 is formed over substantially the entire area of ​​the stacked body 1000. Here, the contact region CA is located between two adjacent mesa structures 200 in plan view.

[0049] In the next step S24, the insulating film 240 deposited on the contact region CA is removed. Specifically, as shown in FIG. 32, a resist pattern R2' is formed by photolithography in an area other than the contact region CA adjacent to the mesa structure 200. Next, as shown in FIG. 33, using this resist pattern R2' as a mask, the insulating film 240 deposited on the contact region CA is removed by wet etching. Thereafter, as shown in FIG. 34, the resist pattern R2' is removed.

[0050] In the next step S25, as shown in FIG. 35, impurities are diffused from the contact region CA adjacent to the mesa structure 200 to form an impurity region 800. Specifically, impurities such as Zn are injected and diffused from the contact region CA. For example, the injection rate and time of the impurities are adjusted so that the impurity region 800 diffuses into the contact layer 400, the substrate 100, the etching stop layer 500, and the sidewall 200a1 of the first multilayer film reflector 200a. At this time, the insulating film 240 serves as a mask during the impurity diffusion. For example, if SiO2 is used as the material for the insulating film 240, vacancy diffusion occurs from Ga at the SiO2 interface due to the diffusion, decompression, and heating, making it easier for the impurity to diffuse over a wide area. In the first example, after the first etching, impurities are diffused from the first multilayer mirror 200a in the region 350 adjacent to the first mesa structure 150, and therefore there is a possibility that the impurities may also diffuse into the selectively oxidized layer 210. In contrast, in the second example, etching is performed until the contact layer 400 is exposed, and then the second mesa structure 200 is formed, and then the impurities are diffused from the contact region CA, so that the impurities are unlikely to diffuse into the selectively oxidized layer 210.

[0051] In the next step S26, the remaining insulating film 240 is removed as shown in Fig. 36. Specifically, the insulating film 240 formed in the region other than the contact region CA is removed.

[0052] In the next step S27, as shown in Fig. 37, the peripheral portion of the selectively oxidized layer 210 (see Fig. 36) is oxidized to form the current confinement layer 200d. Specifically, the mesa structure 200 is exposed to a water vapor atmosphere, and the selectively oxidized layer 210 is oxidized from the side (selectively oxidized), thereby forming the current confinement layer 200d in which the non-oxidized region 200d1 is surrounded by the oxidized region 200d2.

[0053] 38, in the next step S28, an insulating film 250 is formed on the mesa structure 200 and on the contact region CA adjacent thereto. Specifically, the insulating film 250 is formed on substantially the entire area of ​​the stacked body 1000 in which the mesa structure 200 is formed. Here, the contact region CA is located between two adjacent mesa structures 200 in a plan view.

[0054] In the next step S29, the insulating film 250 on the mesa structure 200 and in the contact region CA adjacent to the mesa structure 200 is removed to form contact holes. Specifically, as shown in FIG. 39, a resist pattern R3' is formed by photolithography in the region other than the contact region CA adjacent to the mesa structure 200 and the top of the mesa structure 200. Next, using this resist pattern R3' as a mask, the insulating film 250 on the contact region CA and the insulating film 250 on the top of the mesa structure 200 is removed by wet etching to form contact holes CH1 and CH2 for electrode contact, as shown in FIG. 41. Thereafter, the resist pattern R3' is removed.

[0055] 42, in the next step S30, an anode electrode 600 is provided on the contact region CA adjacent to the mesa structure 200. Specifically, for example, an Au / Ti film is formed in the contact region CA by EB evaporation, and the resist and the Au / Ti on the resist are lifted off to form the anode electrode 600 in the contact hole CH1.

[0056] 43, a cathode electrode 300 is provided on the top of the mesa structure 200. Specifically, for example, an Au / Ti film is formed on the top of the mesa structure 200 by EB evaporation, and the resist and the Au / Ti on the resist are lifted off, thereby forming the cathode electrode 300 in the contact hole CH2 on the top of the mesa structure 200.

[0057] 44, in the final step S32, metal wiring 700 is formed to connect the anode electrode 600 provided in the contact region CA adjacent to the mesa structure 200 to the electrode pad. Thereafter, annealing is performed, the back surface of the substrate 100 (the surface opposite to the surface on the second mesa structure 200 side) is polished to thin the substrate, and anti-reflective coating is applied to the back surface of the substrate 100, thereby forming a plurality of surface-emitting laser arrays in which a plurality of surface-emitting lasers 10 are two-dimensionally arranged on a single wafer. Thereafter, the wafer is separated into a plurality of surface-emitting laser array chips by dicing.

[0058] The order of steps S30 and S31 may be reversed.

[0059] (3) Action of the surface-emitting laser according to the first embodiment of the present technology In the surface-emitting laser 10, a current is injected into the contact region CA from electrode pads arranged around the surface-emitting laser array via metal wiring 700 and the anode electrode 600. The current injected into the contact region CA passes through a low-resistance impurity region 800 and the first multilayer film reflector 200a, and then into the active layer 200b. This causes the active layer 200b to emit light, and the light is amplified while repeatedly reflected between the first and second multilayer film reflectors 200a and 200c until it satisfies the oscillation conditions, at which point it is emitted as laser light from the substrate 100 side.

[0060] (4) Effects of the surface-emitting laser according to the first embodiment of the present technology The surface-emitting laser 10 according to the first embodiment of the present technology includes a substrate 100 and a mesa structure 200 formed on the substrate 100. The mesa structure 200 includes a first multilayer reflector 200a stacked on the substrate 100, an active layer 200b stacked on the first multilayer reflector 200a, and a second multilayer reflector 200c stacked on the active layer 200b. An impurity region 800 is provided across a contact region CA adjacent to the mesa structure 200 and in contact with the anode electrode 600, and a sidewall portion 200a1 of the portion of the mesa structure 200 constituted by the first multilayer reflector 200a. As a result, the resistance of the portion of the current path from the contact region CA to the sidewall portion 200a1 is reduced, so that current can be efficiently injected into the active layer 200b. In this case, even if the impurity concentration of the impurity region 800 is relatively low, a current can be efficiently injected into the active layer 200b. As a result, the surface-emitting laser 10 can efficiently inject current into the active layer 200b while suppressing deterioration in the crystallinity of the layers stacked above the contact region CA.

[0061] On the other hand, in the surface-emitting laser disclosed in Patent Document 1, for example, the contact region is doped with a high concentration of impurities, which deteriorates the crystallinity of the layers stacked above the contact region. Also, in this surface-emitting laser, the impurities are doped only in the contact region, so there are many parts on the current path from the contact region to the active layer that are not made low-resistance, making it impossible to efficiently inject current into the active layer.

[0062] The impurity region 800 is continuous from the contact region CA to the sidewall 200a1, thereby reducing the resistance in the entire region between the contact region CA and the sidewall 200a1, allowing current to be injected into the active layer 200b more efficiently.

[0063] The mesa structure 200 includes the entire first multilayer reflector 200 a , and the contact area CA includes a part of the substrate 100 .

[0064] The mesa structure 200 includes the entire first multilayer reflector 200a, and the surface-emitting laser 10 further includes a contact layer 400 disposed between the substrate 100 and the first multilayer reflector 200a, and the contact region CA includes a part of the contact layer 400. Furthermore, the contact region includes a part of the substrate 100.

[0065] The thickness of the contact layer 400 is 1 μm or less. In this case, the resistance of the contact layer 400 itself increases, but it is possible to suppress light absorption by the contact layer 400. Even if the resistance of the contact layer 400 itself increases, the low-resistance impurity region 800 extends to the contact layer 400, so the resistance of the contact layer 400 in the current path does not increase significantly or becomes low.

[0066] The impurity concentration of the impurity region 800 is 5×10 19 cm -3 This makes it possible to more reliably prevent deterioration in the crystallinity of the layers stacked above the contact region CA (for example, the first multilayer reflector 200a, the active layer 200b, and the second multilayer reflector 200c).

[0067] Another cathode electrode 300 is in contact with the surface of the mesa structure 200 on the same side as the anode electrode 600 with respect to the contact region CA. This makes it possible to prevent the surface-emitting laser 10 from becoming large, compared to when both electrodes are arranged on opposite surfaces, for example.

[0068] The substrate 100 is a semi-insulating substrate or a lightly doped substrate, which can suppress light absorption by the substrate 100.

[0069] The surface-emitting laser 10 emits light on the side of the substrate 100 opposite to the mesa structure 200. This allows the cathode electrode 300 to be arranged larger than in a surface-emitting laser that emits light from the top of the mesa structure, for example, and allows current to flow over a wider area of ​​the mesa structure, resulting in increased optical output.

[0070] The surface-emitting laser 10 uses an AlGaAs-based compound semiconductor.

[0071] The surface-emitting laser 10 further includes a current confinement layer 200d disposed between the first multilayer reflector 200a and the second multilayer reflector 200c. The current confinement layer 200d has the effect of confining light and electrons in a narrow region, thereby enabling the surface-emitting laser 10 to reduce the threshold current for laser oscillation.

[0072] The first and second multilayer reflectors 200a and 200c are both semiconductor multilayer reflectors, which can improve the conductivity of the current path from at least the contact region CA to the active layer 200b.

[0073] A surface-emitting laser array in which the surface-emitting lasers 10 are arranged two-dimensionally can realize a highly efficient and low-power-consumption surface-emitting laser array.

[0074] The first example of the method for manufacturing the surface-emitting laser 10 includes the steps of: laminating at least a first multilayer reflector 200a, an active layer 200b, and a second multilayer reflector 200c in this order on a substrate 100 to form a laminate 1000; etching the laminate 1000 until at least a part of the side surface of the first multilayer reflector 200a is exposed to form a first mesa structure 150; depositing an insulating film 240 on the first mesa structure 150 and a region 350 adjacent to the first mesa structure 150; the step of removing the insulating film 240 deposited in the region 350 where the first mesa structure 150 is located; the step of diffusing impurities from the adjacent region to the sidewall portion 200a1 of the portion of the first mesa structure 150 that is composed of the first multilayer film reflector 200a; the step of etching the stack 1000 until the other portion of the side surface of the first multilayer film reflector 200a is exposed to produce a second mesa structure 200 that replaces the first mesa structure 150; and the step of providing an anode electrode 600 on the region adjacent to the second mesa structure 200.

[0075] In this case, impurities are injected from the first multilayer film reflector 200a in the region 350 adjacent to the first mesa structure 150, so that the impurities can be sufficiently distributed to the side wall portion 200a1 of the part of the first multilayer film reflector 200a that constitutes the first mesa structure 150.

[0076] In the first example, in the process of producing the laminate 1000, a contact layer 400 is laminated on the substrate 100 before laminating the first multilayer film reflector 200a on the substrate 100, and in the process of forming the second mesa structure 200, the laminate 1000 is etched until at least the contact layer 400 is exposed. This allows the anode electrode 600 to be provided on the contact layer 400 .

[0077] The second example of the method for manufacturing the surface-emitting laser 10 includes the steps of: stacking at least a first multilayer reflector 200a, an active layer 200b, and a second multilayer reflector 200c in this order on a substrate 100 to produce a stack 1000; etching the stack 1000 until at least a part of the side surface of the first multilayer reflector 200a is exposed to form a mesa structure 200; depositing an insulating film 240 on the mesa structure 200 and a region 350 adjacent to the mesa structure 200; removing the insulating film 240 deposited on the adjacent region 350; diffusing impurities from the adjacent region 350 to the sidewall portion 200a1 of the portion of the mesa structure 200 formed by the first multilayer reflector 200a; and providing an anode electrode 600 on the adjacent region 350.

[0078] In this case, the mesa structure 200 is formed by etching once, thereby reducing the number of steps. Furthermore, since the impurities are implanted from the contact region CA adjacent to the mesa structure 200, the impurities can be prevented from diffusing into the selectively oxidized layer 210.

[0079] In the second example, in the process of producing the laminate 1000, a contact layer 400 is laminated on the substrate 100 before laminating the first multilayer film reflector 200a on the substrate 100, and in the process of forming the mesa structure 200, the laminate 1000 is etched until the contact layer 400 is exposed. This allows the anode electrode 600 to be provided on the contact layer 400 .

[0080] 2. Surface-emitting laser according to the second embodiment of the present technology As shown in FIG. 45, the surface-emitting laser 20 according to the second embodiment has the same configuration as the surface-emitting laser 10 according to the first embodiment, except that it does not have the contact layer 400. That is, in the surface-emitting laser 20, the mesa structure 220 also includes the entire first multilayer reflector 200a, and the contact region CA1 includes a part of the substrate 100. Here, the contact region CA1 also includes a part of the etching stop layer 500. In the surface-emitting laser 20, the upper surface (bottom surface of the contact hole CH1) of the contact region CA1 adjacent to the mesa structure 220 (here, between two adjacent mesa structures 20 in plan view) is located within the substrate 100. In the surface-emitting laser 20, the impurity region 820 includes a part of the substrate 100, a part of the etching stop layer 500, and the sidewall portion 200a1 of the first multilayer film reflector 200a. The surface-emitting laser 20 can also be manufactured by a manufacturing method similar to the first and second examples of the manufacturing method for the surface-emitting laser 10 (excluding the step of stacking the contact layer 400). The surface-emitting laser 20 according to the second embodiment has the same effects as the surface-emitting laser 10, and also reduces the number of manufacturing steps since the contact layer 400 is not stacked. 3. Surface-emitting laser according to the third embodiment of the present technology As shown in FIG. 46, the surface-emitting laser 30 according to the third embodiment does not have the contact layer 400 and the etching stop layer 500, unlike the surface-emitting laser 10 according to the first embodiment. Furthermore, in the surface-emitting laser 30, the mesa structure 230 includes a portion other than the bottom (lower portion) of the first multilayer reflector 200a (including the upper portion of the first multilayer reflector 200a), and the contact region CA2 includes a part of the bottom portion of the first multilayer reflector 200a. The mesa structure 230 is substantially the same as the first mesa structure 150 described in the first example of the method for manufacturing the surface-emitting laser 10. That is, in the surface-emitting laser 30, the upper surface (bottom surface of the contact hole CH1) of the contact region CA2 adjacent to the mesa structure 230 (here, located between two adjacent mesa structures 230 in a plan view) is located within the first multilayer film reflector 200a. Here, the contact region CA2 includes part of the substrate 100 and part of the lower part of the first multilayer film reflector 200a. Note that the contact region CA2 does not necessarily have to include part of the substrate 100. The surface-emitting laser 20 has the same effects as the surface-emitting laser 10, and since the contact layer 400 and the etching stop layer 500 are not stacked, the number of manufacturing steps can be further reduced compared to the second embodiment. In the surface-emitting laser 30, the impurity region 830 includes the lower portion and sidewall portion 200a1 of the first multilayer film reflector 200a, and part of the substrate 100. The surface-emitting laser 30 can be manufactured by a method similar to the first example of the method for manufacturing the surface-emitting laser 10 described above (however, the region 350 adjacent to the first mesa structure 150 becomes the contact region CA2).

[0081] 4. <Modification of the surface-emitting laser according to the present technology> The present technology is not limited to the above-described embodiments, and various modifications are possible.

[0082] For example, in a surface-emitting laser 10A according to Modification 1 of the first embodiment shown in FIG. 47, the bottom surface (etched bottom surface) of the contact hole CH1, which is the upper surface of the contact region CA3, is located within the etching stopper layer 500. In the first modification, the impurity region 850 includes a part of the etching stop layer 500, a part of the contact layer 400, a part of the substrate 100, and a sidewall portion 200a1 of the first multilayer reflector 200a. In the surface-emitting laser 10A as well, the impurity region 850 reduces the resistance of the current path from the contact region CA3 to the sidewall portion 200a1, allowing current to flow efficiently from the anode electrode 600 to the active layer 200b.

[0083] For example, in a surface-emitting laser 10B according to Modification 2 of the first embodiment shown in FIG. 48, the bottom surface (etched bottom surface) of the contact hole CH1, which is the upper surface of the contact region CA4, is located within the contact layer 400. In the second modification, the impurity region 860 includes a part of the etching stop layer 500, a part of the contact layer 400, a part of the substrate 100, and a sidewall portion 200a1 of the first multilayer reflector 200a. In the surface-emitting laser 10B as well, the impurity region 860 reduces the resistance of the current path from the contact region CA4 to the sidewall portion 200a1, allowing current to flow efficiently from the anode electrode 600 to the active layer 200b.

[0084] For example, in a surface-emitting laser 10C according to Modification 3 of the first embodiment shown in FIG. 49, the bottom surface (etched bottom surface) of the contact hole CH1, which is the upper surface of the contact region CA5, is located within the substrate 100. In the third modification, the impurity region 870 includes a part of the etching stop layer 500, a part of the contact layer 400, a part of the substrate 100, and the sidewall portion 200a1 of the first multilayer reflector 200a. In the surface-emitting laser 10C as well, the impurity region 870 reduces the resistance of the current path from the contact region CA5 to the sidewall portion 200a1, allowing current to flow efficiently from the anode electrode 600 to the active layer 200b.

[0085] In each of the above embodiments and modifications, both the first and second multilayer film reflectors 200a, 200c are semiconductor multilayer film reflectors, but the present invention is not limited to this. For example, the first multilayer reflector 200a may be a semiconductor multilayer reflector, and the second multilayer reflector 200c may be a dielectric multilayer reflector, which is also a type of distributed Bragg reflector. For example, the first multilayer reflector 200a may be a dielectric multilayer reflector, and the second multilayer reflector 200c may be a semiconductor multilayer reflector. For example, both the first and second multilayer film reflectors 200a and 200b may be dielectric multilayer film reflectors. The semiconductor multilayer reflector has low light absorption and is electrically conductive, and from this viewpoint, the semiconductor multilayer reflector is suitable for the first multilayer reflector 200a, which is located on the emission side (rear side) and on the current path from the anode electrode 600 to the active layer 200b. On the other hand, a dielectric multilayer reflector has extremely low light absorption, and from this point of view, a dielectric multilayer reflector is suitable for the first multilayer reflector 200 on the emission side (rear surface side).

[0086] In the above-described embodiments and modified examples, a back-side emitting surface-emitting laser that emits laser light from the substrate side has been used as an example. However, the present technology can also be applied to a surface-emitting surface-emitting laser that emits laser light from the mesa structure side. In this case, it is preferable to form an emission port inside the electrode provided on the top of the mesa structure by making the electrode on the top of the mesa structure ring-shaped or frame-shaped, or to make the electrode on the top of the mesa structure an electrode that is transparent to the oscillation wavelength.

[0087] In the above-described embodiments and modifications, the surface-emitting laser 10 using an AlGaAs-based compound semiconductor has been described as an example, but the present technology can also be applied to a surface-emitting laser using, for example, a GaN-based compound semiconductor. Specifically, at least one of the first and second multilayer film reflectors 200a, 200b may be a GaN-based semiconductor multilayer film reflector, or at least one of the first and second multilayer film reflectors 200a, 200b may be a GaN-based dielectric multilayer film reflector. The GaN-based compound semiconductor used for at least one of the first and second multilayer film reflectors 200a and 200b may be, for example, GaN / AlGaN.

[0088] In the above-described embodiments and modifications, a surface-emitting laser array in which the surface-emitting lasers 10 are two-dimensionally arranged has been described as an example, but the present technology is not limited thereto. The present technology can also be applied to a surface-emitting laser array in which the surface-emitting lasers 10 are one-dimensionally arranged, a single surface-emitting laser 10, etc.

[0089] 5. <Examples of use of surface-emitting lasers that utilize this technology> The surface-emitting lasers according to the above embodiments and modifications of the present technology can be applied to electronic devices that emit laser light, such as a TOF (Time Of Flight) sensor. When applied to a TOF sensor, the surface-emitting lasers can be applied to, for example, a range image sensor using a direct TOF measurement method or a range image sensor using an indirect TOF measurement method. In a range image sensor using the direct TOF measurement method, a light pulse with a short pulse width is transmitted from a light source and an electrical pulse is generated by a light-receiving element to directly determine the arrival timing of photons at each pixel in the time domain. The present disclosure can be applied to the light source used in such a case. Furthermore, in the indirect TOF method, the time of flight of light is measured using a semiconductor element structure in which the detection and accumulation amount of light-generated carriers changes depending on the arrival timing of the light. The present disclosure can also be applied as a light source when using such an indirect TOF method.

[0090] The surface-emitting laser according to the present technology may be realized as a light source of the above-mentioned TOF sensor mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, or a robot.

[0091] The surface-emitting laser according to the present technology may be realized as a light source of a device that forms or displays an image by laser light (for example, a laser printer, a laser copier, a projector, a head-mounted display, a head-up display, etc.).

[0092] The present technology can also be configured as follows. (1) This technology involves a substrate and a mesa structure formed on the substrate; Equipped with The mesa structure includes: at least a portion of a first multilayer film reflector laminated on the substrate; an active layer laminated on the first multilayer film reflector; a second multilayer film reflector laminated on the active layer; and Including, a surface-emitting laser, wherein an impurity region is provided across a contact region adjacent to the mesa structure that is in contact with an electrode and a sidewall portion of the mesa structure that is configured by the first multilayer film reflector. (2) The surface-emitting laser according to (1), wherein the impurity region is continuous from the contact region to the sidewall portion. (3) The surface-emitting laser according to (1) or (2), wherein the mesa structure includes the entire first multilayer reflector, and the contact region includes a part of the substrate. (4) The surface-emitting laser according to (1) or (2), wherein the mesa structure includes a portion other than the bottom of the first multilayer reflector, and the contact region includes a portion of the bottom of the first multilayer reflector. (5) The surface-emitting laser according to (1) or (2), wherein the mesa structure includes the entire first multilayer reflector and further includes a contact layer disposed between the substrate and the first multilayer reflector, and the contact region includes a portion of the contact layer. (6) The surface-emitting laser according to claim (5), wherein the contact region includes a part of the substrate. (7) The surface-emitting laser according to (5) or (6), wherein the contact layer has a thickness of 1 μm or less. (8) The impurity concentration of the impurity region is 5×10 19 cm -3 The surface-emitting laser according to any one of (1) to (7), wherein the surface-emitting laser has a luminance of less than 100 nm. (9) A surface-emitting laser according to any one of (1) to (8), wherein another electrode is in contact with the surface of the mesa structure on the same side as the electrode with respect to the contact region. (10) The surface-emitting laser according to any one of (1) to (9), wherein the substrate is a semi-insulating substrate or a lightly doped substrate. (11) The surface-emitting laser according to any one of (1) to (10), wherein the surface-emitting laser emits light to the side of the substrate opposite to the mesa structure side. (12) The surface-emitting laser according to any one of (1) to (11), wherein the surface-emitting laser uses an AlGaAs-based compound semiconductor or a GaN-based compound semiconductor. (13) The surface-emitting laser according to any one of (1) to (12), further comprising a current confinement layer disposed between the first multilayer reflector and the second multilayer reflector. (14) The surface-emitting laser according to any one of (1) to (13), wherein at least one of the first and second multilayer film reflectors is a semiconductor multilayer reflector. (15) The surface-emitting laser according to any one of (1) to (13), wherein at least one of the first and second multilayer film reflectors is a dielectric multilayer film reflector. (16) A surface-emitting laser array in which the surface-emitting lasers according to any one of (1) to (15) are two-dimensionally arranged. (17) An electronic device comprising the surface-emitting laser array according to (16). (18) forming a laminate by stacking at least a first multilayer reflector, an active layer, and a second multilayer reflector on a substrate in this order; forming a first mesa structure by etching the laminate until at least a part of a side surface of the first multilayer film reflector is exposed; forming an insulating film on the first mesa structure and an area adjacent to the first mesa structure; removing the insulating film formed in the adjacent region; diffusing impurities from the adjacent region to a sidewall portion of the first mesa structure that is configured as the first multilayer film reflector; a step of forming a second mesa structure in place of the first mesa structure by etching the laminate until at least another portion of the side surface of the first multilayer film reflector is exposed; providing an electrode on a region adjacent to the second mesa structure; A method for manufacturing a surface-emitting laser, comprising: (19) The method for manufacturing a surface-emitting laser according to (18), wherein in the step of generating the stack, a contact layer is stacked on the substrate before stacking the first multilayer film reflector, and in the step of forming the second mesa structure, the stack on which the first mesa structure is formed is etched until at least the contact layer is exposed. (20) forming a laminate by stacking at least a first multilayer reflector, an active layer, and a second multilayer reflector on a substrate in this order; forming a mesa structure by etching the laminate until at least a part of a side surface of the first multilayer film reflector is exposed; forming an insulating film on the mesa structure and an area adjacent to the mesa structure; removing the insulating film formed in the adjacent region; diffusing impurities from the adjacent region to a sidewall portion of the mesa structure that is configured by the first multilayer film reflector; providing an electrode on the adjacent region; A method for manufacturing a surface-emitting laser, comprising: (21) A method for manufacturing a surface-emitting laser according to (20), wherein in the step of generating the stack, a contact layer is stacked on the substrate before stacking the first multilayer film reflector, and in the step of forming the mesa structure, the stack is etched until at least the contact layer is exposed. [Explanation of symbols]

[0093] 10: surface-emitting laser, 100: substrate, 150: first mesa structure, 200: second mesa structure (mesa structure), 200a: first multilayer reflector, 200b: active layer, 200c: second multilayer reflector, 200d: current confinement layer, 400: contact layer, 600: anode electrode (electrode), 800: impurity region, 1000: stacked body, CA, CA1, CA2, CA3, CA4, CA5: contact region.

Claims

1. A substrate; a mesa structure formed on the substrate; Equipped with The mesa structure includes: at least a portion of a first multilayer film reflector laminated on the substrate; an active layer laminated on the first multilayer film reflector; a second multilayer film reflector laminated on the active layer; and Including, an impurity region having a higher impurity concentration than other regions is provided across a contact region adjacent to the mesa structure and in contact with an electrode and a sidewall portion of the mesa structure that is made up of the first multilayer film reflector, the mesa structure includes the entire first multilayer reflector, The contact region includes a portion of the substrate.

2. A substrate; a mesa structure formed on the substrate; Equipped with The mesa structure includes: at least a portion of a first multilayer film reflector laminated on the substrate; an active layer laminated on the first multilayer film reflector; a second multilayer film reflector laminated on the active layer; and Including, an impurity region having a higher impurity concentration than other regions is provided across a contact region adjacent to the mesa structure and in contact with an electrode and a sidewall portion of the mesa structure that is made up of the first multilayer film reflector, the mesa structure includes a portion other than a bottom portion of the first multilayer film reflector, The contact region includes a part of the bottom of the first multilayer reflector.

3. A substrate; a mesa structure formed on the substrate; Equipped with The mesa structure includes: at least a portion of a first multilayer film reflector laminated on the substrate; an active layer laminated on the first multilayer film reflector; a second multilayer film reflector laminated on the active layer; and Including, an impurity region having a higher impurity concentration than other regions is provided across a contact region adjacent to the mesa structure and in contact with an electrode and a sidewall portion of the mesa structure that is made up of the first multilayer film reflector, the mesa structure includes the entire first multilayer reflector, a contact layer disposed between the substrate and the first multilayer film reflector; the contact region includes a portion of the contact layer; The contact region includes a portion of the substrate.

4. A substrate; a mesa structure formed on the substrate; Equipped with The mesa structure includes: at least a portion of a first multilayer film reflector laminated on the substrate; an active layer laminated on the first multilayer film reflector; a second multilayer film reflector laminated on the active layer; and Including, an impurity region having a higher impurity concentration than other regions is provided across a contact region adjacent to the mesa structure and in contact with an electrode and a sidewall portion of the mesa structure that is made up of the first multilayer film reflector, A surface-emitting laser that emits light to the side of the substrate opposite to the mesa structure side.

5. 5. The surface-emitting laser according to claim 1, wherein at least one of the first and second multilayer film reflectors is a dielectric multilayer film reflector.

6. 6. The surface-emitting laser according to claim 1, wherein the impurity region is continuous from the contact region to the sidewall portion.

7. the mesa structure includes the entire first multilayer reflector, a contact layer disposed between the substrate and the first multilayer film reflector; 7. The surface-emitting laser according to claim 1, wherein the contact region includes a part of the contact layer.

8. 8. The surface-emitting laser according to claim 3, wherein the contact layer has a thickness of 1 [mu]m or less.

9. The impurity concentration of the impurity region is 5×10 １９ cm －３ The surface-emitting laser according to any one of claims 1 to 8, wherein the surface-emitting laser has a λ / 2 .mu.m or less.

10. 10. The surface-emitting laser according to claim 1, wherein another electrode is in contact with the surface of the mesa structure on the same side as the electrode with respect to the contact region.

11. 11. The surface-emitting laser according to claim 1, wherein the substrate is a semi-insulating substrate or a lightly doped substrate.

12. 12. The surface-emitting laser according to claim 1, wherein an AlGaAs-based compound semiconductor or a GaN-based compound semiconductor is used.

13. 13. The surface-emitting laser according to claim 1, further comprising a current confinement layer disposed between the first multilayer reflector and the second multilayer reflector.

14. 5. The surface-emitting laser according to claim 1, wherein at least one of the first and second multilayer film reflectors is a semiconductor multilayer film reflector.

15. A surface-emitting laser array in which the surface-emitting lasers according to any one of claims 1 to 14 are two-dimensionally arranged.

16. An electronic device comprising the surface-emitting laser array according to claim 15.

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