Light-emitting element

Abstract

The present invention provides a light-emitting element capable of suppressing a degradation in reliability.　The light-emitting element according to the present technology comprises: a substrate; a laminated structure which is disposed on the substrate and in which a plurality of layers including a light-emitting layer are laminated; and an intermediate structure disposed between the substrate and the laminated structure and including a layer having a lattice strain. According to the light-emitting element according to the present technology, it is possible to provide a light-emitting element capable of suppressing a degradation in reliability.

Description

Light-emitting element

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

[0002] 2. Description of the Related Art Conventionally, light emitting elements such as surface emitting lasers, edge emitting lasers, and light emitting diodes are known.

[0003] Among conventional light-emitting elements, there are some that have a laminated structure in which a plurality of layers including a light-emitting layer are stacked on a substrate (see, for example, Patent Documents 1 and 2).

[0004] Japanese Patent Laid-Open No. 5-211346 Japanese Patent Laid-Open No. 2011-35115

[0005] However, in conventional light-emitting devices, crystal defects (for example, dislocations) present in the substrate may propagate to the stacked structure, resulting in a decrease in reliability.

[0006] Therefore, a main object of the present technology is to provide a light-emitting element capable of suppressing a decrease in reliability.

[0007] The present technology provides a light-emitting device comprising: a substrate; a stacked structure disposed on the substrate, the stacked structure including a plurality of layers including a light-emitting layer; and an intermediate structure disposed between the substrate and the stacked structure, the intermediate structure including a lattice-strained layer. The lattice-strained layer may guide dislocations from the substrate in a lateral direction. The lattice constant of the lattice-strained layer may be different from that of the substrate. The absolute value of the difference between the lattice constant of the lattice-strained layer and that of the substrate may be 0.41 Å or less. The lattice-strained layer may include a III-V compound semiconductor. The lattice-strained layer may include at least two of Al, Ga, and In, and at least one of P and As. The lattice-strained layer may include an n-type compound semiconductor or a p-type compound semiconductor. When the lattice-strained layer includes an n-type compound semiconductor, it may include any one of Si, Se, Te, and Ge as an n-type impurity. When the lattice-strained layer includes a p-type compound semiconductor, it may include any one of C, Mg, Zn, and B as a p-type impurity. The substrate may be any one of a GaAs substrate, an InP substrate, a GaN substrate, a Si substrate, a Ge substrate, an SOI substrate, and a GOI substrate. The substrate may include a semi-insulating substrate or an insulating substrate. The substrate includes impurities, and the impurity concentration of the substrate is 1×10 16 / cm 3 1x10 or more 19 / cm 3 or less. The intermediate structure may include a plurality of layers having the lattice distortion. The intermediate structure may include a buffer layer disposed between the layers having the lattice distortion. The intermediate structure may include a buffer layer disposed between the layer having the lattice distortion and the stacked structure. The intermediate structure may include a buffer layer disposed between the layer having the lattice distortion and the substrate. The intermediate structure may have a composition gradient and / or a carrier concentration gradient. The thickness of the layer having the lattice distortion may be equal to or less than a critical film thickness. The lattice distortion may be tensile strain or compressive strain. The carrier concentration of the layer having lattice distortion may be 8×10 17 / cm 3The plurality of layers may include a reflector disposed on the opposite side of the light-emitting layer from the intermediate structure side, and may emit light to the opposite side of the substrate from the intermediate structure side.

[0008] 1. A cross-sectional view of a light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 3A is a plan view of a light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 3B is a cross-sectional view taken along line 3B-3B of FIG. 3A. A schematic cross-sectional view of a surface-emitting laser array according to a comparative example. A schematic cross-sectional view of the light-emitting device of FIG. 1. A flowchart for describing an example of a manufacturing method of the light-emitting device of FIG. 1. A cross-sectional view of each step of ... FIG. 1 is a cross-sectional view of a light-emitting device according to Example 4 of an embodiment of the present technology. FIG. 2 is a cross-sectional view of a light-emitting device according to Example 5 of an embodiment of the present technology. FIG. 3 is a cross-sectional view of a light-emitting device according to Example 6 of an embodiment of the present technology. FIG. 4 is a cross-sectional view of a light-emitting device according to Example 7 of an embodiment of the present technology. FIG. 5 is a cross-sectional view of a light-emitting device according to Example 8 of an embodiment of the present technology. FIG. 6 is a cross-sectional view of a light-emitting device according to Example 9 of an embodiment of the present technology. FIG. 7 is a cross-sectional view of a light-emitting device according to Example 10 of an embodiment of the present technology. FIG. 8 is a plan view of a light-emitting device according to Example 10 of an embodiment of the present technology. FIG. 9 is a cross-sectional view of a light-emitting device according to Example 11 of an embodiment of the present technology. FIG. 10 is a cross-sectional view of a light-emitting device according to Example 11 of an embodiment of the present technology. FIG. 11 is a cross-sectional view of a light-emitting device according to Example 12 of an embodiment of the present technology. FIG. 12 is a cross-sectional view of a light-emitting device according to Example 13 of an embodiment of the present technology. FIG. 13 is a cross-sectional view of a light-emitting device according to Example 14 of an embodiment of the present technology. FIG. 14 is a cross-sectional view of a light-emitting device according to Example 15 of an embodiment of the present technology. FIG. 15 is a cross-sectional view of a light-emitting device according to Example 16 of an embodiment of the present technology. FIG. 16 is a plan view of a light-emitting device according to Example 17 of an embodiment of the present technology.Fig. 10 is a cross-sectional view of a light emitting and receiving device including a light emitting element according to Example 18 of an embodiment of the present technology. Fig. 11 is a cross-sectional view of a light emitting element according to Modification 1 of Example 1 of an embodiment of the present technology. Fig. 12 is a cross-sectional view of a light emitting element according to Modification 2 of Example 1 of an embodiment of the present technology. Fig. 13 is a cross-sectional view of a light emitting element according to Modification 3 of Example 1 of an embodiment of the present technology. Fig. 14 is a diagram illustrating an example of application of a light emitting element according to the present technology to a distance measurement device. Fig. 15 is a block diagram illustrating an example of a schematic configuration of a vehicle control system. Fig. 16 is an explanatory diagram illustrating an example of an installation position of a distance measurement device.

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

[0010] The description will be made in the following order: 0. Introduction 1. Light-emitting device according to Example 1 of one embodiment of the present technology 2. Light-emitting device according to Example 2 of one embodiment of the present technology 3. Light-emitting device according to Example 3 of one embodiment of the present technology 4. Light-emitting device according to Example 4 of one embodiment of the present technology 5. Light-emitting device according to Example 5 of one embodiment of the present technology 6. Light-emitting device according to Example 6 of one embodiment of the present technology 7. Light-emitting device according to Example 7 of one embodiment of the present technology 8. Light-emitting device according to Example 8 of one embodiment of the present technology 9. Light-emitting device according to Example 9 of one embodiment of the present technology 10. Light-emitting device according to Example 10 of one embodiment of the present technology 11. Light-emitting device according to Example 11 of one embodiment of the present technology 12. Light-emitting device according to Example 12 of one embodiment of the present technology 13. Light-emitting device according to Example 13 of one embodiment of the present technology 14. Light-emitting device according to Example 14 of one embodiment of the present technology 15. Light-emitting device according to Example 15 of one embodiment of the present technology 16. Light-emitting device according to Example 16 of one embodiment of the present technology 17. Light-emitting device according to Example 17 of one embodiment of the present technology 18. Light receiving and emitting device according to Example 18 of an embodiment of the present technology 19. Modification of the present technology 20. Application example to electronic devices 21. Example in which the light emitting element is applied to a distance measurement device 22. Example in which the distance measurement device is mounted on a moving body

[0011] <0. Introduction> Among conventional light-emitting elements (e.g., surface-emitting lasers, edge-emitting lasers, light-emitting diodes, etc.), there are light-emitting elements having a layered structure (element portion) in which multiple layers, including semiconductor layers, are stacked on a substrate (see, for example, Patent Documents 1 and 2).

[0012] In conventional light-emitting devices, it is difficult to prevent crystal defects, such as dislocations, present in the substrate from propagating to the stacked structure that is the element portion, which can lead to a decrease in reliability.

[0013] Therefore, after extensive research, the inventors have succeeded in arranging a layer with lattice distortion between the substrate and the laminated structure, thereby deflecting crystal defects, such as dislocations, inherent in the substrate laterally and suppressing the propagation of the dislocations to the laminated structure, which is a novel finding of the inventors.

[0014] The inventors then developed a light-emitting element according to the present technology as a light-emitting element that embodies this new finding. The light-emitting element according to the present technology can provide a light-emitting element that can suppress a decrease in reliability.

[0015] Hereinafter, a light-emitting device according to an embodiment of the present technology will be described in detail with reference to several examples. For convenience, the upper side of a cross-sectional view such as FIG. 1 will be referred to as "upper" and the lower side will be referred to as "lower."

[0016] <1. Light-emitting device according to example 1 of one embodiment of the present technology>

[0017] Hereinafter, a light-emitting element 10 according to Example 1 of an embodiment of the present technology will be described. <Configuration of Light-Emitting Element> (Overall Configuration) Fig. 1 is a cross-sectional view of the light-emitting element 10 according to Example 1 of an embodiment of the present technology. Fig. 2 is a plan view of the light-emitting element 10 according to Example 1 of an embodiment of the present technology. Fig. 1 is a cross-sectional view taken along line 1-1 in Fig. 2.

[0018] The light-emitting element 10 is, for example, a vertical cavity surface-emitting laser (VCSEL). The light-emitting element 10 is, for example, a back-emitting VCSEL. The oscillation wavelength λ of the light-emitting element 10 is, for example, 400 nm to 1550 nm (for example, 940 nm in the case of a GaAs-based element). The light-emitting element 10 is, for example, driven by a driver (drive circuit). The driver is, for example, configured to include a power supply and a transistor (for example, a metal-oxide-semiconductor field-effect transistor (MOSFET)) that controls the on / off of the current supply from the power supply to the light-emitting element 10.

[0019] 1 and 2, the light-emitting element 10 includes, for example, a substrate 101, a stacked structure LS arranged on the substrate 101, the stacked structure LS being formed by stacking a plurality of layers (constituent layers) including a light-emitting layer 107, and an intermediate structure IS arranged between the substrate 101 and the stacked structure LS. Hereinafter, the direction in which the plurality of layers are stacked in the stacked structure LS (the vertical direction) will also be referred to as the "stacking direction."

[0020] The stacked structure LS has, as an example, a stepped mesa. The stepped mesa has a first mesa M1 with a large diameter located on the lower tier and a second mesa M2 with a small diameter located on the upper tier. The stepped mesa is also called a "light-emitting mesa." As an example, each of the first and second mesas M1 and M2 is circular in plan view (see FIG. 2). That is, in this example, each of the first and second mesas M1 and M2 is cylindrical. As an example, the diameter (average diameter) of the first mesa M1 is several μm to several tens of μm (e.g., 10 μm to 30 μm).

[0021] As an example, the stacked structure LS includes a first contact layer 104, a first semiconductor multilayer reflector 105 (p-DBR) having an oxide constriction layer 106 disposed therein, a light emitting layer 107, a second semiconductor multilayer reflector 108 (n-DBR), a second contact layer 109, a dielectric multilayer reflector 110, and a metal reflector 111, which are stacked in this order from the substrate 101 side (bottom side). Here, the first semiconductor multilayer reflector 105 having the oxide constriction layer 106 disposed therein, the light emitting layer 107, the second semiconductor multilayer reflector 108, and the second contact layer 109 form a first mesa M1, and the dielectric multilayer reflector 110 and the metal reflector 111 form a second mesa M2. That is, the first mesa M1 protrudes from the first contact layer 104, and the second mesa M2 protrudes from the first mesa M1 (more specifically, from the second contact layer 109). The semiconductor layers included in the stacked structure LS are made of, for example, a III-V compound semiconductor (for example, a GaAs-based compound semiconductor: a compound semiconductor lattice-matched to GaAs). That is, the light-emitting element 10 can be configured as, for example, a GaAs-based VCSEL.

[0022] The side surface of the first mesa M1 is covered with an insulating film 114. Examples of materials for the insulating film 114 include SiO2, SiN, and SiON.

[0023] As an example, a circumferential (e.g., ring-shaped) anode electrode 112 (p-side electrode) is provided so as to surround the stacked structure LS on the upper surface of the first contact layer 104. An insulating film 114 is interposed between the anode electrode 112 and the stacked structure LS.

[0024] As an example, a circumferential (e.g., ring-shaped) cathode electrode 113 (n-side electrode) is provided on the upper surface of the first mesa M1 (more specifically, on the upper surface of the second contact layer 109) so as to surround the dielectric multilayer film reflector 110.

[0025] The light-emitting element 10 has a double heterostructure in which the light-emitting layer 107 is sandwiched in the stacking direction between first and second semiconductor multilayer film reflectors 105 and 108 of different conductivity types, and holes and electrons can undergo radiative recombination (radiative recombination) in the light-emitting layer 107. Note that first and second clad layers of different conductivity types may be provided between the first and second semiconductor multilayer film reflectors 105 and 108 so as to sandwich the light-emitting layer 107.

[0026] In the light-emitting element 10, a resonator is configured including a light-emitting layer 107 and first and second reflectors that sandwich the light-emitting layer 107 in the stacking direction. The first reflector is disposed on the intermediate structure IS side (bottom side) of the light-emitting layer 107 and includes a first semiconductor multilayer reflector 105. The first reflector is also called a lower reflector. The second reflector is disposed on the opposite side (upper side) of the light-emitting layer 107 from the intermediate structure IS side and includes a second semiconductor multilayer reflector 108, a dielectric multilayer reflector 110, and a metal reflector 111. The second reflector is also called an upper reflector. The light-emitting element 10 emits laser light to the opposite side (back side, bottom side) of the substrate 101 from the intermediate structure IS side.

[0027] (Substrate) The substrate 101 is preferably any one of a GaAs substrate, an InP substrate, a GaN substrate, a Si substrate, a Ge substrate, an SOI substrate, and a GOI substrate.

[0028] Here, the substrate 101 is, for example, a semi-insulating substrate or an insulating substrate, such as an SI (Semi-Insulating)-GaAs substrate, an i-GaAs substrate, etc. The semi-insulating substrate has a resistivity range of, for example, 0.8×10 8 Ω・cm or more 6×10 8 The insulating substrate has a specific resistance of, for example, 6×10 8The light emitting element 10 is a back-emitting VCSEL that emits laser light from the back side of the substrate 101, and by using a substrate with a low impurity concentration (including zero impurity concentration) for the substrate 101, light absorption in the substrate 101 can be suppressed, and ultimately the loss of light intensity of the emitted light can be reduced.

[0029] The substrate 101 may contain p-type or n-type impurities (dopants), and in that case, the impurity concentration is 1×10 16 / cm 3 1x10 or more 19 / cm 3 Preferably, it is 1×10 or less. 16 / cm 3 3x10 or more 18 / cm 3 More preferably, it is 1×10 or less. 16 / cm 3 1x10 or more 18 / cm 3 More preferably, it is 1×10 or less. 16 / cm 3 1x10 or more 17 / cm 3 It is more preferable that the impurity concentration is 1×10 or less. Examples of p-type impurities that can be contained in the substrate 101 include Zn, Mg, B, Be, and C. Examples of n-type impurities that can be contained in the substrate 101 include Si, Se, Te, and Ge. In particular, when the substrate 101 contains Si as an n-type impurity, the impurity concentration is 1×10 16 / cm 3 3x10 or more 18 / cm 3 It is preferable that:

[0030] (Intermediate Structure IS) As an example, the intermediate structure IS has a structure in which buffer layers and defect propagation suppression layers are alternately stacked. More specifically, in the intermediate structure IS, a first buffer layer 102A, a first defect propagation suppression layer 103A, a second buffer layer 102B, a second defect propagation suppression layer 103B, and a third buffer layer 102C are stacked in this order from the substrate 101 side (bottom side). Hereinafter, the first to third buffer layers 102A to 102C will be collectively referred to as buffer layers 102, and the first and second defect propagation suppression layers 103A and 103B will be collectively referred to as defect propagation suppression layers 103, as appropriate. Details of the intermediate structure IS will be described later.

[0031] (First Contact Layer) As described above, the first contact layer 104 is disposed on the substrate 101 via the intermediate structure IS. The first contact layer 104 may, for example, contain a high concentration of p-type impurities (for example, 1×10 19 / cm 3 The p-type impurity may be, for example, Zn, Mg, B, Be, C, or the like.

[0032] (First Semiconductor Multilayer Reflector) The first semiconductor multilayer reflector 105 is, for example, a semiconductor multilayer reflector doped with p-type impurities, exhibiting low light absorption, high reflectivity, and electrical conductivity. Multilayer reflectors are also called distributed Bragg reflectors (DBRs). The first semiconductor multilayer reflector 105 has a structure in which high-refractive index layers and low-refractive index layers with different refractive indices are alternately stacked with an optical thickness equal to one-quarter of the emission wavelength of the light-emitting layer 107. The low-refractive index layers are made of a compound semiconductor containing Al (e.g., AlGaAs, AlAs, etc.). The high-refractive index layers are made of a compound semiconductor (e.g., AlGaAs, GaAs, etc.). The low-refractive index layers are high-Al composition layers with a higher Al composition than the high-refractive index layers. It is preferable that the refractive index difference (Al composition difference) between the high-refractive index layers and the low-refractive index layers is large. This is because high reflectivity can be obtained with a small number of pairs. The Al composition of the low refractive index layer is preferably 0.8 or more, more preferably 0.85 or more, even more preferably 0.9 or more, and even more preferably 0.95 or more. The Al composition of the high refractive index layer is preferably 0.2 or less, more preferably 0.15 or less, even more preferably 0.1 or less, and even more preferably 0.05 or less. Examples of p-type impurities (p-type dopants) in the first semiconductor multilayer film reflector 105 include Zn, Mg, B, Be, and C.

[0033] (Oxidized Constriction Layer) The oxidized constriction layer 106, for example, has a non-oxidized region 106a and an oxidized region 106b surrounding the non-oxidized region 106a. The outer shape (shape in plan view) of the non-oxidized region 106a is determined by the inner peripheral shape of the oxidized region 106b. The inner peripheral shape of the oxidized region 106b is determined by the outer peripheral shape of the mesa structure MS. The diameter (average diameter) of the non-oxidized region 106a is determined by the inner diameter (average inner diameter) of the oxidized region 106b. The oxidized constriction layer 106 is preferably disposed at or near the node of a standing wave generated in the resonator. In the oxidized constriction layer, the non-oxidized region is also referred to as an OA (oxide aperture) (hereinafter the same). In the oxidized constriction layer, the diameter of the non-oxidized region, that is, the oxide constriction diameter, is also referred to as the OA diameter.

[0034] The non-oxidized region 106a functions as a current / light passing region. For example, the non-oxidized region 106a includes an Al-containing compound semiconductor (e.g., AlGaAs, AlAs, etc.). The non-oxidized region 106a preferably has an Al composition of 0.8 or more, more preferably 0.85 or more, even more preferably 0.9 or more, and even more preferably 0.95 or more.

[0035] The oxidized region 106b is, for example, a circular (for example, ring-shaped) region in plan view that surrounds the non-oxidized region 106a. The oxidized region 106b has a higher resistance and a lower refractive index than the non-oxidized region 106a, and functions as a current / light confinement region. For example, the oxidized region 106b is made of an oxide containing Al (for example, Al x O y etc.)

[0036] (Light Emitting Layer) The light emitting layer 107 is made of, for example, a compound semiconductor having a band gap energy smaller than that of the first and second semiconductor multilayer film reflectors 105 and 108. The light emitting layer 107 is made of, for example, a GaAs-based compound semiconductor (e.g., GaAs, AlGaAs, InGaAs, InGaAsN, etc.). The light emitting layer 107 may have any of a quantum well structure, a multiple quantum well structure, a quantum wire structure, and a quantum dot structure. The emission wavelength of the light emitting layer 107 is set to, for example, 400 nm to 1550 nm. The light emitting layer 107 is preferably disposed at or near the antinode of a standing wave generated in the resonator.

[0037] The light emitting layer 107 is designed in accordance with the oscillation wavelength λ and the intended use. For example, when laser characteristics are to be obtained in the 900 nm band of the oscillation wavelength λ, the light emitting layer 107 can be designed by combining an InGaAs-based active layer and an AlGaAs-based guide / barrier layer.

[0038] (Second Semiconductor Multilayer Reflector) The second semiconductor multilayer reflector 108 is, for example, a semiconductor multilayer reflector doped with n-type impurities, exhibiting low light absorption, high reflectivity, and electrical conductivity. Multilayer reflectors are also called distributed Bragg reflectors (DBRs). The second semiconductor multilayer reflector 108 has a structure in which high-refractive index layers and low-refractive index layers with different refractive indices are alternately stacked with an optical thickness equal to one-quarter of the emission wavelength of the light-emitting layer 107. The low-refractive index layers are made of compound semiconductors containing Al (e.g., AlGaAs, AlAs). The high-refractive index layers are made of compound semiconductors (e.g., AlGaAs, GaAs, etc.). The low-refractive index layers are high-Al composition layers with a higher Al composition than the high-refractive index layers. It is preferable that the refractive index difference (Al composition difference) between the high-refractive index layers and the low-refractive index layers be as large as possible. This is because high reflectivity can be obtained with a small number of pairs. The Al composition of the low refractive index layer is preferably 0.8 or more, and more preferably 0.85 or more. The Al composition of the high refractive index layer is preferably 0.2 or less, more preferably 0.15 or less, even more preferably 0.1 or less, and even more preferably 0.05 or less. Examples of n-type impurities (n-type dopants) for the second semiconductor multilayer film reflector 108 include Si, Se, Te, and Ge. Here, the reflectivity of the second semiconductor multilayer film reflector 108 is set to be the same as that of the first semiconductor multilayer film reflector 105.

[0039] (Second Contact Layer) As described above, the second contact layer 109 is disposed between the second semiconductor multilayer film reflector 108 and the dielectric multilayer film reflector 110. The second contact layer 109 may, for example, contain a high concentration of n-type impurities (for example, 1×10 19 / cm 3 The second contact layer 109 may be formed of a transparent conductive film made of, for example, ITO (indium tin oxide), IZO (indium zinc oxide), or the like.

[0040] (Dielectric Multilayer Reflector) The dielectric multilayer reflector 110 has low light absorption, high reflectivity, and insulating properties. The multilayer reflector is also called a distributed Bragg reflector (DBR). The dielectric multilayer reflector 110 has a structure in which high-refractive index layers and low-refractive index layers, each having a different refractive index, are alternately stacked with an optical thickness equal to one-quarter of the emission wavelength of the light-emitting layer 107. The dielectric multilayer reflector 110 is preferably made of a material containing at least one of SiO2, TiO2, Ta2O5, SiN, a-Si, MgF2, and CaF2. For example, the dielectric multilayer reflector 110 may be made of SiO2 / TiO2, Ta2O5 / SiO2, or a-Si / Ta2O5. Instead of the dielectric multilayer film reflector 110, a single dielectric layer made of, for example, any of SiO2, TiO2, Ta2O5, SiN, a-Si, MgF2, and CaF2 may be used.

[0041] (Metal Reflecting Mirror) As an example, the metal reflecting mirror 111 is provided in a solid state on the dielectric multilayer film reflecting mirror 110. The metal reflecting mirror 111 is made of a metal plating such as Au, Ag, or Al. The metal reflecting mirror 111 and the dielectric multilayer film reflecting mirror 110 form a hybrid mirror.

[0042] (Anode Electrode) The anode electrode 112 may have a single-layer structure or a multilayer structure. The anode electrode 112 is made of at least one metal (including alloys) selected from the group consisting of, for example, Au, Ag, Pd, Pt, Ni, Ti, V, W, Cr, Al, Cu, Zn, Sn, Ge, and In. When the anode electrode 112 has a multilayer 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, or Ag / Pd. The anode electrode 112 is electrically connected to the anode side of the driver.

[0043] (Cathode Electrode) The cathode electrode 113 may have a single-layer structure or a laminated structure. The cathode electrode 113 is made of at least one metal (including alloys) selected from the group consisting of, for example, Au, Ag, Pd, Pt, Ni, Ti, V, W, Cr, Al, Cu, Zn, Sn, Ge, and In. When the cathode electrode 113 has a laminated structure, it is made of materials such as Ti / Au, Ti / Al, Ti / Al / Au, Ti / Pt / Au, Ni / Au, Ni / Au / Pt, Ni / Pt, Pd / Pt, Ag / Pd, or the like. The cathode electrode 113 is electrically connected to the cathode side of the driver.

[0044] Incidentally, substrates such as semiconductor substrates, semi-insulating substrates, and insulating substrates contain a considerable number of crystal defects (lattice defects), and semi-insulating substrates in particular are known to contain a relatively large number of dislocations. That is, semi-insulating substrates are known to have particularly high EPD (Hitch Pit Density). Here, the comparative surface-emitting laser array shown in FIG. 3A has emitters (light-emitting portions) that emit light and dead emitters (non-light-emitting portions) that do not emit light, for example, within the area surrounded by a white oval frame. In FIG. 3A, it can be seen that multiple dead emitters are present in a row in the horizontal direction. The presence of such dead emitters is due to the occurrence of dislocations extending laterally near the light-emitting layer, as shown in FIG. 3B, which is a cross-sectional view taken along 3B-3B of FIG. 3A. In FIG. 3B, the first structure includes a lower reflector, and the second structure includes an upper reflector (similar to FIGS. 4 and 5). As can be seen from Figure 4, which is a schematic cross-sectional view of a surface-emitting laser array of a comparative example, most of the dislocations present in the semi-insulating substrate propagate to the upper layers, namely, the first structure, the light-emitting layer, and the second structure. Some of these dislocations propagate laterally near the light-emitting layer. The presence of such dislocations may result in the generation of dead emitters and a decrease in emitter output, i.e., a decrease in reliability.

[0045] Therefore, in the light emitting device 10, in order to suppress such a decrease in reliability, an intermediate structure IS is disposed between the substrate 101 and the laminated structure LS, as shown in FIG.

[0046] (Details of the intermediate structure IS) The defect propagation suppression layer 103 is a layer having lattice distortion. The defect propagation suppression layer 103 can guide dislocations from the substrate 101 laterally due to this lattice distortion (see FIG. 5). It has been confirmed that a layer having lattice distortion has the function of propagating dislocations laterally. Compared to the surface-emitting laser array of the comparative example, the defect propagation suppression layer 103 sufficiently suppresses the propagation of dislocations inherent in the semi-insulating substrate to the upper layers, that is, the first structure, the light-emitting layer, and the second structure (see FIG. 5).

[0047] It is preferable that the lattice constant of the defect propagation suppression layer 103 is different from that of the substrate 101. This makes it possible to generate lattice strain in the defect propagation suppression layer 103. The lattice constants of the first and second defect propagation suppression layers 103A and 103B may be the same or different. The lattice constant of GaAs, which is the material of the substrate 101, is 5.653 Å.

[0048] The lattice strain is tensile or compressive. More specifically, the lattice strain is tensile when the lattice constant of the defect propagation suppression layer 103 is smaller than that of the substrate 101, and is compressive when the lattice constant of the defect propagation suppression layer 103 is larger than that of the substrate 101.

[0049] The absolute value (absolute difference) of the difference between the lattice constant of the defect propagation suppression layer 103 and the lattice constant of the substrate 101 is preferably 0.41 Å or less, and more preferably 0.21 Å or more and 0.41 Å or less. This allows the lattice strain of the defect propagation suppression layer 103 to be set to a value necessary to guide dislocations from the substrate 101 laterally while setting the thickness of the defect propagation suppression layer 103 to a certain degree.

[0050] The thickness of the defect propagation suppression layer 103 is preferably equal to or less than the critical film thickness. The intermediate structure IS has the first and second defect propagation suppression layers 103A and 103B stacked on top of each other with the second buffer layer 102B interposed therebetween, thereby making it possible to obtain a two-stage (two-stage) defect propagation suppression effect (sufficient defect propagation suppression effect) while keeping the thickness of each layer equal to or less than the critical film thickness.

[0051] The defect propagation suppression layer 103 preferably includes, for example, a compound semiconductor, more specifically, a III-V group compound semiconductor. Specifically, the defect propagation suppression layer 103 preferably includes at least two of Al, Ga, and In, each of which is a group III element, and at least one of P and As, each of which is a group V element. The defect propagation suppression layer 103 may include, for example, a III-V group compound semiconductor such as AlGaInP, AlGaAsP, AlGaInAs, or InGaP. The first and second defect propagation suppression layers 103A and 103B may include the same compound semiconductor or different compound semiconductors.

[0052] The buffer layer 102 preferably contains, for example, a compound semiconductor, more specifically, a III-V group compound semiconductor. Specifically, the buffer layer 102 is, for example, a GaAs layer, an AlGaAs layer, or an AlAs layer. At least two of the first to third buffer layers 102A, 102B, and 102C may contain the same compound semiconductor or different compound semiconductors.

[0053] The thickness of each of the first and third buffer layers 102A and 103C is preferably greater than the thickness of the second buffer layer 102B. The thickness of each of the first and third buffer layers 102A and 103C is preferably two to six times, and more preferably three to five times, the thickness of the second buffer layer 102B. The thickness of the third buffer layer 102C is preferably equal to or greater than the thickness of the first buffer layer 102A.

[0054] The carrier concentration (impurity concentration) of the defect propagation suppression layer 103 is 1.0×10 17 / cm 3 Above 1.0 x 10 18 / cm 3 Preferably, it is less than 8.0 × 10 17 / cm 3 Above 1.0 x 10 18 / cm 3 More preferably, it is less than 1.0 × 10 18 / cm 3 Above 1.0 x 10 19 / cm 3 More preferably, it is less than 1.0 × 10 19 / cm3 Above 1.0 x 10 20 / cm 3 It is more preferable that the impurity concentration (carrier concentration) of an n-type substrate doped with Si is less than 8.0×10. 17 / cm 3 is.

[0055] The carrier concentration (impurity concentration) of the buffer layer 102 is 1.0×10 17 / cm 3 Above 1.0 x 10 18 / cm 3 Preferably, it is less than 8.0 × 10 17 / cm 3 Above 1.0 x 10 18 / cm 3 More preferably, it is less than 1.0 × 10 18 / cm 3 Above 1.0 x 10 19 / cm 3 More preferably, it is less than 1.0 × 10 19 / cm 3 Above 1.0 x 10 20 / cm 3 It is more preferable that it is less than 10 ...

[0056] The defect propagation suppression layer 103 preferably contains an n-type compound semiconductor (specifically, an n-type III-V compound semiconductor) or a p-type compound semiconductor (a p-type III-V compound semiconductor).

[0057] When the defect propagation suppression layer 103 contains an n-type compound semiconductor, it preferably contains any one of Si, Se, Te, and Ge as an n-type impurity.

[0058] When the defect propagation suppression layer 103 contains a p-type compound semiconductor, it preferably contains any one of C, Mg, Zn, B, and Be as a p-type impurity.

[0059] The defect propagation suppression layer 103 has a thickness of, for example, several nm to several tens of nm (for example, 10 nm). The defect propagation suppression layer 103 contains n-type or p-type impurities (dopants) at a doping concentration of, for example, 3.0×10 18 / cm 3It's doped up with.

[0060] As described above, the intermediate structure IS includes a first buffer layer 102A disposed between the first defect propagation suppression layer 103A and the substrate 101. The first buffer layer 102A preferably has a lattice constant between the lattice constant of the first defect propagation suppression layer 103A and the lattice constant of the substrate 101. In this case, the first buffer layer 102A can adjust the magnitude of lattice strain introduced into the first defect propagation suppression layer 103A due to the lattice mismatch between the first defect propagation suppression layer 103A and the substrate 101 to an appropriate magnitude. The first buffer layer 102A is, for example, a GaAs layer, an AlGaAs layer, an AlAs layer, or the like. The thickness of the first buffer layer 102A is, for example, several tens of nanometers (e.g., 80 nm). The first buffer layer 102A contains an n-type or p-type impurity (dopant) at a doping concentration of, for example, 3.0×10 18 / cm 3 It's doped up with.

[0061] As described above, the intermediate structure IS includes a second buffer layer 102B disposed between two adjacent first and second defect propagation suppression layers 103A and 103B. The lattice constant of the second buffer layer 102B is preferably the same as or closer to that of the substrate 101 than that of the first and second defect propagation suppression layers 103A and 103B. In this case, the second buffer layer 102B functions as a spacer between the first and second defect propagation suppression layers 103A and 103B and can adjust the magnitude of lattice strain induced in the second defect propagation suppression layer 103B due to lattice mismatch between the second defect propagation suppression layer 103B and the substrate 101 to an appropriate magnitude. The second buffer layer 102B may be made of, for example, a GaAs layer, an AlGaAs layer, or an AlAs layer. The thickness of the second buffer layer 102B is, for example, several tens of nanometers (e.g., 20 nm). The second buffer layer 102B has an n-type or p-type impurity (dopant) doped at a doping concentration of, for example, 3.0×10 18 / cm 3 It's doped up with.

[0062] As described above, the intermediate structure IS includes a third buffer layer 102C disposed between the second defect propagation suppression layer 103B and the stacked structure LS. The third buffer layer 102C preferably has a lattice constant between the lattice constant of the second defect propagation suppression layer 103B and the lattice constant of the first contact layer 104, which is one of the layers in the stacked structure LS adjacent to the third buffer layer 102C. In this case, the third buffer layer 102C can alleviate the lattice mismatch between the second defect propagation suppression layer 103B and the first contact layer 104, thereby suppressing the occurrence of lattice strain within the stacked structure LS. The third buffer layer 102C may be, for example, a GaAs layer, an AlGaAs layer, an AlAs layer, or the like. The thickness of the third buffer layer 102C is, for example, several tens of nanometers (e.g., 80 nm). The third buffer layer 102C contains n-type or p-type impurities (dopants) at a doping concentration of, for example, 3.0×10 18 / cm 3 It's doped up with.

[0063] The intermediate structure IS may include at least two defect propagation suppression layers 103 having different compositions and / or carrier concentrations. That is, the first and second defect propagation suppression layers 103A and 103B may have different compositions and / or carrier concentrations when they include the same compound semiconductor.

[0064] The intermediate structure IS may have a composition gradient in which the composition of, for example, Al, Ga, In, P, As, etc. changes (becomes gradually larger or smaller) in a region of a lattice constant range from −0.21 Å to +0.41 Å with the lattice constant of GaAs as the reference. In this case, the composition gradient may be between the first and second defect propagation suppression layers 103A and 103B, or between the first to third buffer layers 102A, 102B, and 102C, or the intermediate structure IS as a whole may have the composition gradient.

[0065] The intermediate structure IS may have a carrier concentration gradient in which the carrier concentration changes (becomes gradually higher or gradually lower) in a region of a lattice constant range from −0.21 Å to +0.41 Å, for example, based on the lattice constant of GaAs. In this case, the carrier concentration gradient may be between the first and second defect propagation suppression layers 103A and 103B, or between the first to third buffer layers 102A, 102B, and 102C, or the intermediate structure IS as a whole may have the carrier concentration gradient. It is particularly preferable that the carrier concentration gradient gradually increases from the substrate 101 side to the stacked structure LS side.

[0066] The intermediate structure IS may include at least two buffer layers 102 having different compositions and / or carrier concentrations. That is, at least two of the first to third buffer layers 102A to 102C may have different compositions and / or carrier concentrations when they include the same compound semiconductor.

[0067] <<Operation of Surface-Emitting Laser>> In the light-emitting element 10, a current flowing from the anode side of the driver to the anode electrode 112 passes through the first contact layer 104 and the lower part of the first semiconductor multilayer film reflector 105 in this order, is constricted by the oxide constriction layer 106, and is injected into the light-emitting layer 107 through the upper part of the first semiconductor multilayer film reflector 105. At this time, the light-emitting layer 107 emits light, and the light travels back and forth between the first and second reflectors while being amplified by the light-emitting layer 107 and constricted by the oxide constriction layer 106, and when oscillation conditions are satisfied, it is emitted as laser light to the back side (lower surface side) of the substrate 101. The current injected into the light-emitting layer 107 flows out to the cathode side of the driver via the second semiconductor multilayer film reflector 108, the second contact layer 109, and the cathode electrode 113 in this order.

[0068] Furthermore, since the propagation of dislocations from the substrate 101 to the stacked structure LS is suppressed in the light-emitting element 10, the element is prevented from becoming a dead emitter or from causing a decrease in output, and therefore the desired laser light can be obtained stably even if the above operations are performed continuously.

[0069] <<Example of a Method for Manufacturing Light-Emitting Device>> An example of a method for manufacturing the light-emitting device 10 will be described below with reference to the flowchart of Fig. 6. As an overall flow, first, a semiconductor manufacturing method using semiconductor manufacturing equipment is used to simultaneously produce a plurality of light-emitting devices 10 on a single wafer (hereinafter, also referred to as "substrate 101" for convenience) that is the base material of the substrate 101. Next, the plurality of light-emitting devices 10 that are connected together are separated from each other by dicing (e.g., stealth dicing) to obtain chip-shaped light-emitting devices 10.

[0070] In the first step S1, a stacked body L is produced (see FIG. 7 ). Specifically, the stacked body L is produced by stacking, in this order, a first buffer layer 102A, a first defect propagation suppression layer 103A, a second buffer layer 102B, a second defect propagation suppression layer 103B, a third buffer layer 102C, a first contact layer 104, a first semiconductor multilayer reflector 105, an oxidized layer 106S (e.g., an AlGaAs layer, an AlAs layer, or the like) that will be the material of the oxide constriction layer 106, a light-emitting layer 107, a second semiconductor multilayer reflector 108, and a second contact layer 109 on a substrate 101 serving as a growth substrate by an epitaxial crystal growth method such as MOCVD (Metal Organic Chemical Vapor Deposition). In this case, when the first defect propagation suppression layer 103A is stacked on the substrate 101 via the first buffer layer 102A, lattice mismatch between the substrate 101 and the first defect propagation suppression layer 103A causes lattice strain in the first defect propagation suppression layer 103A, and some dislocations from the substrate 101 are guided laterally. When the second defect propagation suppression layer 103B is stacked on the second buffer layer 102B, lattice mismatch between the substrate 101 and the second defect propagation suppression layer 103B causes lattice strain in the second defect propagation suppression layer 103B, and other dislocations from the substrate 101 are guided laterally. When the third buffer layer 102C is stacked on the second defect propagation suppression layer 103B, dislocations from the substrate 101 hardly propagate to the third buffer layer 102C. Even when each component layer of the stacked structure LS is stacked on the third buffer layer 102C, dislocations from the substrate 101 hardly propagate to the component layers. When producing the laminate L, methyl-based organometallic gases such as trimethylaluminum (TMAl), trimethylgallium (TMGa), and trimethylindium (TMIn), and arsine (AsH) gas are used as raw materials for the compound semiconductor, disilane (SiH) is used as a raw material for the donor impurity, and carbon tetrabromide (CBr) is used as a raw material for the acceptor impurity.

[0071] In the next step S2, the mesa structure MS is formed (see FIG. 8). Specifically, first, a resist pattern for forming the mesa structure MS is formed on the stacked body by photolithography. Next, the stacked body is etched by, for example, dry etching using the resist pattern as a mask. This etching is continued until at least the first contact layer 104 is exposed. As a result, the mesa structure MS is formed. After that, the resist pattern is removed.

[0072] In the next step S3, an oxidized constriction layer is formed (see FIG. 9). Specifically, the mesa structure MS (see FIG. 8) formed in the stack is exposed to a high-temperature water vapor atmosphere to oxidize the oxidized layer 106S by several micrometers from the side surface toward the center of the mesa structure MS. As a result, the mesa structure MS becomes the first mesa M1.

[0073] In the next step S4, the anode electrode 112 is formed (see FIG. 10). Specifically, the anode electrode 112 is formed in a circumferential shape (e.g., a ring shape) on the first contact layer 104 so as to surround the first mesa M1 by, for example, a lift-off method. At this time, the electrode material is deposited by, for example, evaporation, sputtering, or the like.

[0074] In the next step S5, the insulating film 114 is formed. Specifically, first, the insulating film 114 is formed on the entire surface (see FIG. 11). Next, the insulating film 114 on the anode electrode 112 and the insulating film 114 on the second contact layer 109 are removed by photolithography and etching to expose the anode electrode 112 and the second contact layer 109 (see FIG. 12). As a result, the insulating film 114 is formed only on the side surface of the first mesa M1.

[0075] In the next step S6, the cathode electrode 113 is formed (see FIG. 13 ). Specifically, the cathode electrode 113 is formed in a circumferential shape (e.g., a ring shape) on the second contact layer 109 by, for example, lift-off so as to surround the non-oxidized region 106 a in plan view. At this time, the electrode material is deposited by, for example, vapor deposition, sputtering, or the like.

[0076] In the next step S7, the dielectric multilayer film reflector 110 is formed. Specifically, first, a dielectric multilayer film DMF, which is the material for the dielectric multilayer film reflector 110, is deposited over the entire surface (see FIG. 14). Next, photolithography and etching are used to remove the dielectric multilayer film reflector DMF other than the dielectric multilayer film DMF covering the center of the top surface of the stacked structure LS (specifically, the top surface of the second contact layer 109) (see FIG. 15). As a result, the anode electrode 112 and the cathode electrode 113 are exposed, and the dielectric multilayer film reflector 110 is formed in the center of the top surface of the stacked structure LS. The dielectric multilayer film reflector 110 can also be formed by lift-off, for example.

[0077] In the final step S8, the metal reflector 111 is formed (see FIG. 16). Specifically, the metal reflector 111 is formed on the dielectric multilayer film reflector 110 by, for example, plating. As a result, the second mesa M2 is formed on the second contact layer 109. Note that, prior to plating, it is preferable to form a seed layer in advance in the area to be plated.

[0078] <Effects of the Light-Emitting Element> The effects of the light-emitting element 10 will be described below.

[0079] The light-emitting element 10 comprises a substrate 101, a laminated structure LS arranged on the substrate 101, in which a plurality of layers including a light-emitting layer 107 are stacked, and an intermediate structure IS arranged between the substrate 101 and the laminated structure LS, and including a defect propagation suppression layer 103 (a layer having lattice distortion).

[0080] In the light emitting device 10, the defect propagation suppression layer 103 can suppress the propagation of dislocations from the substrate 101 to the stacked structure LS, thereby suppressing a decrease in reliability.

[0081] 2. Light-emitting device according to Example 2 of one embodiment of the present technology

[0082] Hereinafter, a light emitting device 20 according to Example 2 of an embodiment of the present technology will be described. Fig. 17 is a cross-sectional view of the light emitting device 20 according to Example 2 of an embodiment of the present technology.

[0083] As shown in FIG. 17, the light emitting device 20 has the same configuration as the light emitting device 10 according to the first example, except that the intermediate structure IS does not have the third buffer layer 102C.

[0084] According to the light-emitting element 20, since the third buffer layer 102C is not provided between the second defect propagation suppression layer 103B and the stacked structure LS, there is a risk of lattice defects occurring in the stacked structure LS due to lattice mismatch between the second defect propagation suppression layer 103B and the stacked structure LS. However, the number of constituent layers of the intermediate structure IS can be reduced while achieving effects generally similar to those of the light-emitting element 10 according to Example 1.

[0085] <3. Light-emitting device according to Example 3 of one embodiment of the present technology>

[0086] Hereinafter, a light emitting device 30 according to Example 3 of an embodiment of the present technology will be described. Fig. 18 is a cross-sectional view of the light emitting device 30 according to Example 3 of an embodiment of the present technology.

[0087] As shown in FIG. 18, the light-emitting element 30 has the same configuration as the light-emitting element 10 of Example 1, except that the intermediate structure IS does not have the second defect propagation suppression layer 103B and the third buffer layer 102C.

[0088] According to the light-emitting element 30, the second defect propagation suppression layer 103B and the third buffer layer 102C are not provided, and therefore the effect of suppressing the propagation of dislocations from the substrate 101 to the stacked structure LS is inferior to that of the light-emitting element 10 of Example 1, but the number of constituent layers of the intermediate structure IS can be further reduced.

[0089] 4. Light-emitting device according to Example 4 of one embodiment of the present technology

[0090] Hereinafter, a light emitting device 40 according to Example 4 of an embodiment of the present technology will be described. Fig. 19 is a cross-sectional view of the light emitting device 40 according to Example 4 of an embodiment of the present technology.

[0091] As shown in Figure 19, the light-emitting element 40 has a configuration similar to that of the light-emitting element 10 of Example 1, except that the intermediate structure IS does not have the first buffer layer 102A, the second defect propagation suppression layer 103B, and the third buffer layer 102C.

[0092] According to the light-emitting element 40, the first buffer layer 102A, the second defect propagation suppression layer 103B, and the third buffer layer 102C are not provided, and therefore the effect of suppressing the propagation of dislocations from the substrate 101 to the stacked structure LS is inferior to that of the light-emitting element 10 of Example 1, and the magnitude of the lattice strain introduced into the first defect propagation suppression layer 103A cannot be adjusted; however, the number of constituent layers of the intermediate structure IS can be further reduced.

[0093] <5. Light-emitting device according to Example 5 of one embodiment of the present technology>

[0094] Hereinafter, a light emitting device 50 according to Example 5 of an embodiment of the present technology will be described. Fig. 20 is a cross-sectional view of a light emitting device 50 according to Example 5 of an embodiment of the present technology.

[0095] As shown in Figure 20, the light-emitting element 50 has a configuration similar to that of the light-emitting element 10 of Example 1, except that the intermediate structure IS does not have the second buffer layer 102B, the second defect propagation suppression layer 103B, and the third buffer layer 102C.

[0096] According to the light-emitting element 50, the second buffer layer 102B, the second defect propagation suppression layer 103B, and the third buffer layer 102C are not provided, and therefore the effect of suppressing the propagation of dislocations from the substrate 101 to the stacked structure LS is inferior to that of the light-emitting element 10 of Example 1, and there is a risk of lattice defects occurring in the stacked structure LS due to lattice mismatch between the first defect propagation suppression layer 103A and the stacked structure LS; however, the number of constituent layers of the intermediate structure IS can be further reduced.

[0097] <6. Light-emitting device according to Example 6 of one embodiment of the present technology>

[0098] Hereinafter, a light emitting device 60 according to Example 6 of an embodiment of the present technology will be described. Fig. 21 is a cross-sectional view of a light emitting device 60 according to Example 6 of an embodiment of the present technology.

[0099] As shown in FIG. 21, the light-emitting element 60 has a configuration similar to that of the light-emitting element 10 of Example 1, except that the intermediate structure IS does not have the first buffer layer 102A, the second buffer layer 102B, the second defect propagation suppression layer 103B, and the third buffer layer 102C.

[0100] According to the light-emitting element 60, the first buffer layer 102A, the second buffer layer 102B, the second defect propagation suppression layer 103B, and the third buffer layer 102C are not provided, and therefore the effect of suppressing the propagation of dislocations from the substrate 101 to the stacked structure LS is inferior to that of the light-emitting element 10 of Example 1, there is a risk of lattice defects occurring in the stacked structure LS due to lattice mismatch between the first defect propagation suppression layer 103A and the stacked structure LS, and the magnitude of the lattice strain introduced into the first defect propagation suppression layer 103A cannot be adjusted, but the number of constituent layers of the intermediate structure IS can be reduced to the maximum.

[0101] 7. Light-emitting device according to Example 7 of one embodiment of the present technology

[0102] Hereinafter, a light emitting device 70 according to Example 7 of an embodiment of the present technology will be described. Fig. 22 is a cross-sectional view of the light emitting device 70 according to Example 7 of an embodiment of the present technology.

[0103] As shown in FIG. 22, the light emitting device 70 has the same configuration as the light emitting device 10 according to the first embodiment, except that the substrate 101 is an SOI (Silicon on Insulator) substrate or a GOI (Germanium on Insulator) substrate.

[0104] In the light emitting element 70, the substrate 101 has first and second semiconductor substrates 101a and 101c, and an oxide film 101b disposed between the first and second semiconductor substrates 101a and 101c.

[0105] When the substrate 101 is an SOI substrate, the first and second semiconductor substrates 101a and 101c are Si substrates, and the oxide film 101b is made of SiO2.

[0106] When the substrate 101 is a GOI substrate, the first and second semiconductor substrates 101a and 101c are Ge substrates, and the oxide film 101b is made of GeO2.

[0107] According to the light emitting device 70, the same effects as those of the light emitting device 10 according to the first embodiment can be obtained.

[0108] 8. Light-emitting device according to Example 8 of one embodiment of the present technology

[0109] Hereinafter, a light emitting device 80 according to Example 8 of an embodiment of the present technology will be described. Fig. 23 is a cross-sectional view of a light emitting device 80 according to Example 8 of an embodiment of the present technology.

[0110] 23 , the light-emitting element 80 has the same configuration as the light-emitting element 10 according to Example 1, except that it does not have the dielectric multilayer film reflector 110 and the metal reflector 111, and the cathode electrode 113 is provided in a solid state on the second contact layer 109. In this case, the cathode electrode 113 can also function as a metal reflector.

[0111] Although the light emitting device 80 has a lower reflectivity of the second reflector (upper reflector) than the light emitting device 10 according to the first embodiment, it is possible to realize a thin back-emitting VCSEL that can simplify the manufacturing process.

[0112] 9. Light-emitting device according to Example 9 of one embodiment of the present technology

[0113] Hereinafter, a light emitting device 90 according to Example 9 of an embodiment of the present technology will be described. Fig. 24 is a cross-sectional view of a light emitting device 90 according to Example 9 of an embodiment of the present technology.

[0114] As shown in FIG. 24, the light emitting device 90 has the same configuration as the light emitting device 10 according to the first embodiment, except that it does not have the second semiconductor multilayer film reflector 108 .

[0115] Although the light emitting device 90 has a lower reflectivity of the second reflector (upper reflector) than the light emitting device 10 according to the first embodiment, it is possible to realize a thin back-emitting VCSEL that can simplify the manufacturing process.

[0116] <10. Light-emitting device according to Example 10 of an embodiment of the present technology>

[0117] A light emitting device 100 according to a tenth example of an embodiment of the present technology will be described below. Fig. 25 is a cross-sectional view of the light emitting device 100 according to a tenth example of an embodiment of the present technology. Fig. 26 is a plan view of the light emitting device 100 according to a tenth example of an embodiment of the present technology. Fig. 25 is a cross-sectional view taken along line 25-25 in Fig. 26 .

[0118] As shown in FIGS. 24 and 25, the light emitting device 100 has a configuration generally similar to that of the light emitting device 10 according to the first embodiment, except that it has a mesare-less structure.

[0119] The light-emitting element 100 has a plurality of (e.g., four) trenches T (grooves) provided in the stacked structure LS so as to surround the oxide constriction layer 106 in a planar view. The bottom surface of the trench T is the upper surface of the first contact layer 104. An insulating film 114 is provided on the side surfaces and around the opening end of the trench T. The anode electrode 112 has a first electrode 112a provided on the bottom surface of the trench T, and a second electrode 112b whose lower end contacts the first electrode 112a and extends in the depth direction of the trench T within the trench T with the insulating film 114 provided on its side surface. The upper end of the second electrode 112b is exposed to the outside from the opening end of the trench T.

[0120] The trench T also functions to expose the side surface of the layer to be oxidized 106S in the oxidation step during the manufacturing of the light emitting element 100 .

[0121] According to the light emitting device 100, it is possible to realize a back-emitting VCSEL having a mesare-less structure, which can obtain the same effects as the light emitting device 10 according to the first embodiment.

[0122] <11. Light-emitting device according to Example 11 of an embodiment of the present technology>

[0123] Hereinafter, a light emitting device 115 according to Example 11 of an embodiment of the present technology will be described. Fig. 27 is a cross-sectional view of a light emitting device 115 according to Example 11 of an embodiment of the present technology.

[0124] As shown in Figure 27, the light-emitting element 115 has a configuration similar to that of the light-emitting element 100 of Example 10, except that instead of providing an insulating film 114 in the trench T, a circular ion-implanted region IIA in plan view is provided in the peripheral portion of the trench T in the stacked structure LS.

[0125] Examples of ion species for the ion implantation region IIA include B+ and H+.

[0126] According to the light emitting device 115, it is possible to realize a back-emitting VCSEL having a mesare-less structure, which can obtain the same effects as the light emitting device 10 according to the first embodiment.

[0127] <12. Light-emitting device according to Example 12 of an embodiment of the present technology>

[0128] Hereinafter, a light emitting device 120 according to Example 12 of an embodiment of the present technology will be described. Fig. 28 is a cross-sectional view of the light emitting device 120 according to Example 12 of an embodiment of the present technology.

[0129] As shown in FIG. 28, the light emitting device 120 has the same configuration as the light emitting device 10 according to the first embodiment, except that it constitutes a back-emitting surface-emitting laser array.

[0130] In the light-emitting element 120, a plurality of stacked structures LS (excluding the first contact layer 104) are arranged on the substrate 101 via an intermediate structure IS. That is, in the light-emitting element 120, a plurality of surface-emitting lasers (VCSELs) share the substrate 101, the intermediate structure IS, and the first contact layer 104.

[0131] The light emitting element 120 has an electrode layout with a common anode and an independent cathode, and each surface emitting laser can be driven independently.

[0132] According to the light emitting device 120, it is possible to realize a back-emitting surface emitting laser array in which the same effect as that of the light emitting device 10 according to the first embodiment can be obtained for each surface emitting laser.

[0133] <13. Light-emitting device according to Example 13 of an embodiment of the present technology>

[0134] Hereinafter, a light emitting device 130 according to Example 13 of an embodiment of the present technology will be described. Fig. 29 is a cross-sectional view of a light emitting device 130 according to Example 13 of an embodiment of the present technology.

[0135] As shown in FIG. 29, the light emitting device 130 has the same configuration as the light emitting device 10 according to the first embodiment, except that it is a back-emitting InP-based VCSEL.

[0136] In the light emitting device 130, a substrate 101, an intermediate structure IS, a first contact layer 104, a first semiconductor multilayer reflector 105, a BTJ (buried tunnel junction), a dielectric multilayer reflector 110, and a metal reflector 111 are stacked in this order. In the light emitting device 130, the positional relationship between the anode electrode 112 and the cathode electrode 113 is reversed from that of the light emitting device 10 according to the first embodiment.

[0137] (Substrate) The substrate 101 is, for example, a semi-insulating substrate or an insulating substrate, such as an SI (Semi-Insulating)-InP substrate, an i-InP substrate, etc. The substrate 101 may be an n-InP substrate or a p-InP substrate.

[0138] (First Contact Layer) The first contact layer 104 is made of, for example, a highly doped n-InP layer, and the dopant of the n-InP layer can be, for example, Si.

[0139] (First Semiconductor Multilayer Reflector) The first semiconductor multilayer reflector 105 is made of, for example, a compound semiconductor (InP-based compound semiconductor) lattice-matched to InP. The first semiconductor multilayer reflector 105 is made of, for example, n-InP / n-AlGaInAs or n-AlInAs / n-AlGaInAs.

[0140] (Light-Emitting Layer) The light-emitting layer 107 is made of, for example, an InP-based compound semiconductor. More specifically, the light-emitting layer 107 has, for example, a multiple quantum well structure (MQW structure) made of AlGaInAs or GaInAsP. Here, the light-emitting layer 107 is made of, for example, an AlGaInAs / AlGaInAs multiple quantum well layer. The composition and film thickness of the AlGaInAs / AlGaInAs multiple quantum well layer are designed so that the emission wavelength is, for example, 1450 nm (eye-safe band). However, it is preferable to introduce opposing strains into the well layer and the barrier layer. In this case, for example, the magnitude of the strain can be about 0.5%, and the number of wells can be six. The light-emitting region of the light-emitting layer 107 is a region corresponding to a tunnel junction layer 116 (described later).

[0141] (BTJ) The BTJ includes a tunnel junction layer 116 and a buried layer 117. As described above, the BTJ is disposed on the opposite side (upper side) of the light-emitting layer 107 from the substrate 101. In other words, the BTJ is located upstream of the light-emitting layer 107 in the current path from the anode electrode 112 to the cathode electrode 113.

[0142] The buried layer 117 is made of, for example, an n-InP layer, and Si, for example, can be used as a dopant for the n-InP layer.

[0143] The tunnel junction layer 116 is provided in a mesa shape on the light-emitting layer 107. Therefore, hereinafter, the tunnel junction layer 116 is also referred to as a "TJ mesa." The region of the buried layer 117 around the TJ mesa has a higher resistance than the TJ mesa and serves as a current confinement region. The region of the buried layer 117 around the TJ mesa has a lower refractive index than the TJ mesa and serves as a light confinement region. The diameter of the TJ mesa is, for example, several tens of μm.

[0144] The tunnel junction layer 116 includes a p-type semiconductor region 116a and an n-type semiconductor region 116b stacked on top of each other. Here, the p-type semiconductor region 116a is disposed on the light emitting layer 107 side (below) of the n-type semiconductor region 116b. The p-type semiconductor region 116a is made of p-type AlInAs (p-AlInAs) doped with a high concentration of C (carbon), for example. The n-type semiconductor region 116b is made of n-type InP (n-InP) doped with a high concentration of Si, Te, or the like, for example. Note that one of the p-type semiconductor region 116a and the n-type semiconductor region 116b may be made of AlInAs and the other may be made of InP, or both may be made of AlInAs or InP.

[0145] (Dielectric Multilayer Reflector) The dielectric multilayer reflector 110 has low light absorption, high reflectivity, and insulating properties. The multilayer reflector is also called a distributed Bragg reflector (DBR). The dielectric multilayer reflector 110 has a structure in which high-refractive index layers and low-refractive index layers, each having a different refractive index, are alternately stacked with an optical thickness equal to one-quarter of the emission wavelength of the light-emitting layer 107. The dielectric multilayer reflector 110 is preferably made of a material containing at least one of SiO2, TiO2, Ta2O5, SiN, a-Si, MgF2, and CaF2. For example, the dielectric multilayer reflector 110 may be made of SiO2 / TiO2, Ta2O5 / SiO2, or a-Si / Ta2O5. Note that a single dielectric layer may be used instead of the dielectric multilayer reflector 110.

[0146] (Metal Reflecting Mirror) As an example, the metal reflecting mirror 111 is provided in a solid state on the dielectric multilayer film reflecting mirror 110. The metal reflecting mirror 111 is made of a metal plating such as Au, Ag, or Al. The metal reflecting mirror 111 and the dielectric multilayer film reflecting mirror 110 form a hybrid mirror.

[0147] According to the light emitting device 130, it is possible to realize a back-emission type InP-based VCSEL that can obtain the same effects as the light emitting device 10 according to Example 1. <14. Light emitting device according to Example 14 of an embodiment of the present technology>

[0148] Hereinafter, a light emitting device 140 according to Example 14 of an embodiment of the present technology will be described. Fig. 30 is a cross-sectional view of a light emitting device 140 according to Example 14 of an embodiment of the present technology.

[0149] As shown in FIG. 30, the light emitting device 140 has the same configuration as the light emitting device 10 according to the first embodiment, except that it is a surface-emitting VCSEL.

[0150] The light emitting element 140 does not have the dielectric multilayer film reflector 110 or the metal reflector 111 .

[0151] In the light-emitting element 140, the positional relationship between the anode electrode 112 and the cathode electrode 113 and the conductivity type of each semiconductor layer in the stacked structure LS are opposite to those of the light-emitting element 10 according to Example 1. The oxidized constriction layer 106 is disposed on the opposite side (upper side) of the light-emitting layer 107 from the substrate 101 side. The substrate 101 may be any of a semi-insulating substrate, an insulating substrate, and a semiconductor substrate.

[0152] According to the light emitting device 140, it is possible to realize a surface-emitting VCSEL that can obtain the same effects as the light emitting device 10 according to Example 1. <15. Light emitting device according to Example 15 of an embodiment of the present technology>

[0153] Hereinafter, a light emitting device 150 according to Example 15 of an embodiment of the present technology will be described. Fig. 31 is a cross-sectional view of a light emitting device 150 according to Example 15 of an embodiment of the present technology.

[0154] As shown in FIG. 31, the light emitting element 150 has the same configuration as the light emitting element 10 according to the first embodiment, except that it is a back-emitting light emitting diode (LED).

[0155] The light-emitting element 150 does not have the first semiconductor multilayer film reflector 105. In the light-emitting element 150, the positional relationship between the anode electrode 112 and the cathode electrode 113 and the conductivity type of each semiconductor layer in the stacked structure LS are opposite to those of the light-emitting element 10 according to Example 1. In the light-emitting element 150, the oxide constriction layer 106 is disposed on the opposite side (upper side) of the light-emitting layer 107 from the substrate 101 side.

[0156] In the light-emitting element 150, the light emitted upward from the light-emitting layer 107 and reflected by a hybrid mirror consisting of a dielectric multilayer film reflector 110 and a metal reflector 111, and the light emitted downward from the light-emitting layer 107 are combined and emitted to the back side of the substrate 101.

[0157] According to the light emitting device 150, it is possible to realize a rear-emission type LED that can obtain the same effects as the light emitting device 10 according to Example 1. <16. Light emitting device according to Example 16 of an embodiment of the present technology>

[0158] Hereinafter, a light emitting device 160 according to Example 16 of an embodiment of the present technology will be described. Fig. 32 is a cross-sectional view of the light emitting device 160 according to Example 16 of an embodiment of the present technology. Fig. 33 is a plan view of the light emitting device 160 according to Example 16 of an embodiment of the present technology. Fig. 32 is a cross-sectional view taken along line 32-32 of Fig. 33.

[0159] As shown in FIGS. 32 and 33, the light emitting element 160 has substantially the same configuration as the light emitting element 10 according to the first embodiment, except that it is an edge-emitting semiconductor laser (edge-emitting laser).

[0160] In the light-emitting device 160, the stacked structure LS has a rectangular shape in a plan view, and includes a first contact layer 104, a first cladding layer 118 (a p-type compound semiconductor layer), a light-emitting layer 107 (a compound semiconductor layer), a second cladding layer 119 (an n-type compound semiconductor layer), and a second contact layer 109 stacked in this order. The first cladding layer 118, the light-emitting layer 107, and the second cladding layer 119 form a double heterostructure. A cathode electrode 113 (e.g., a stripe electrode) is provided on the second contact layer 109. A pair of anode electrodes 112, 112 is provided on the upper surface of the first contact layer 104, sandwiching the stacked structure LS with an insulating film 114 interposed therebetween. The refractive indexes of the first and second cladding layers 118, 119 are lower than that of the light-emitting layer 107, thereby achieving a light confinement effect in the light-emitting layer 107. The band gap of the first and second cladding layers 118 and 119 is larger than the band gap of the light emitting layer 107, and a carrier confinement effect in the light emitting layer 107 is obtained.

[0161] The light emitting element 160 has a double heterostructure in which one end face and the other end face are cleaved surfaces, forming high-reflectivity reflective surfaces (also called "resonator end faces"). The reflectivities of the pair of reflective surfaces, the first and second reflective surfaces R1 and R2 (see FIG. 33), are set to different values, for example.

[0162] In the light-emitting element 160, a current supplied from the anode side of the driver is injected from the anode electrode 112 through the first contact layer 104 and the first cladding layer 118 in this order into the light-emitting layer 107. At this time, the light-emitting layer 107 emits light, and the light travels back and forth between the first and second reflecting surfaces R1, R2 while being confined within the light-emitting layer 107, and when the oscillation conditions are satisfied, the light is emitted as laser light from each of the first and second reflecting surfaces R1, R2.

[0163] According to the light emitting device 160, it is possible to realize an edge-emitting laser that can obtain the same effects as the light emitting device 10 according to Example 1. <17. Light emitting device according to Example 17 of an embodiment of the present technology>

[0164] Hereinafter, a light emitting device 170 according to Example 17 of an embodiment of the present technology will be described. Fig. 34 is a cross-sectional view of a light emitting device 170 according to Example 17 of an embodiment of the present technology.

[0165] As shown in FIG. 34, the light emitting device 170 has the same configuration as the light emitting device 160 according to Example 16, except that an ion implantation region IIA is provided as a current confinement region in the stacked structure LS.

[0166] In the light-emitting element 170, ion implantation regions IIA are provided on both sides of the stacked structure LS, sandwiching a region corresponding to the cathode electrode 113 (stripe electrode). This makes it possible to increase the current density of the current injected into the light-emitting layer 107.

[0167] According to the light emitting element 170, it is possible to realize a highly efficient edge-emitting laser that can obtain the same effects as the light emitting element 10 according to Example 1. <18. Light receiving and emitting device according to Example 18 of an embodiment of the present technology>

[0168] Hereinafter, a light emitting and receiving device 180 according to Example 18 of an embodiment of the present technology will be described. Fig. 35 is a cross-sectional view of the light emitting and receiving device 180 according to Example 18 of an embodiment of the present technology.

[0169] 35, the light receiving and emitting device 180 can constitute at least a part of a distance measuring device. The light receiving and emitting device 180 includes the light emitting element 10 according to the first embodiment and a light receiving element 500.

[0170] In the light receiving and emitting device 180, the substrate 101 of the light emitting element 10 has a first region A1 in which the stacked structure LS is provided, and a second region A2 adjacent to the first region A1 in which the light receiving element 500 is provided.

[0171] The light receiving element 500 is provided in the substrate 101 so that its light receiving surface is exposed on the back surface of the second region A2 of the substrate 101. As the light receiving element 500, in addition to a PD (photodiode), an APD (avalanche photodiode) made of SiGe can be used.

[0172] Here, a Ge substrate or a Si substrate is used as the substrate 101. The substrate 101 may be provided with at least one of a driver, a readout circuit, an arithmetic circuit, and wiring.

[0173] According to the light emitting and receiving device 180, a light emitting and receiving device including a highly reliable light emitting element 10 can be realized.

[0174] 19. Modifications of the Present Technology The present technology is not limited to the above-described embodiment, and various modifications are possible.

[0175] For example, as shown in Figure 36, in the light-emitting element 10-1 according to variant 1 of Example 1, the cathode electrode 113 may be arranged to cover the top and side surfaces of the dielectric multilayer film reflector 110, so that the cathode electrode 113 also functions as a metal reflector.

[0176] For example, as shown in FIG. 37, in the light-emitting element 10-2 according to the second modification of Example 1, the intermediate structure IS may be composed of first and second defect propagation suppression layers 103A and 103B, and a second buffer layer 102B disposed between the first and second defect propagation suppression layers 103A and 103B.

[0177] For example, as shown in Figure 38, the second reflector (upper reflector) may be composed of a second semiconductor multilayer film reflector 108 and a dielectric multilayer film reflector 110, as in the light-emitting element 10-3 according to variant example 3 of Example 1.

[0178] For example, the light-emitting element according to the present technology may be a GaN-based light-emitting element (e.g., a surface-emitting laser, an edge-emitting laser, a light-emitting diode, or the like) in which a stacked structure LS including a GaN-based compound semiconductor layer (a compound semiconductor lattice-matched to GaN) is arranged on a substrate 101 (e.g., a sapphire substrate, a GaN substrate, or the like) via an intermediate structure IS.

[0179] For example, the substrate 101 may be a composite substrate (for example, a QST (registered trademark) substrate) in which a Si thin film, a Ge thin film, etc. are stacked on a semi-insulating substrate.

[0180] The light-emitting element according to the present technology can use a material that emits light at any wavelength within the wavelength range of 200 to 2500 nm.

[0181] In the light-emitting elements according to the above-described embodiments and modifications, the conductivity types (p-type and n-type) of the semiconductor layer located above the light-emitting layer 107 and the semiconductor layer located below the light-emitting layer 107 may be reversed. In this case, however, the positional relationship between the anode electrode and the cathode electrode must also be reversed.

[0182] Parts of the configurations of the light emitting element and the light receiving and emitting device according to the above-described embodiments and modifications may be combined within a range that does not contradict each other.

[0183] In each of the above embodiments and modifications, the arrangement, material, conductivity type, thickness, width, numerical value, shape, size, etc. of each layer constituting the light-emitting element and light-receiving / light-emitting device can be changed as appropriate within the range in which it functions as a light-emitting element.

[0184] 20. Application Examples to Electronic Devices The technology according to the present disclosure (the present technology) can be applied to various products (electronic devices). For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, or a robot, a low-power device (e.g., a smartphone, a smartwatch, a tablet, a mouse, a laptop computer, etc.), or a wired or wireless communication device.

[0185] The light-emitting element according to the present technology can also be applied as a light source for devices that form or display images using light (for example, printers, copiers, projectors, head-mounted displays, head-up displays, etc.).

[0186] 21. Example in which light emitting element is applied to distance measuring device An application example of the light emitting element 10 according to Example 1 of an embodiment of the present technology will be described below.

[0187] 39 illustrates an example of a schematic configuration of a distance measurement device 1000 (distance measuring device) including a light-emitting element 10, as an example of an electronic device according to the present technology. The distance measurement device 1000 measures the distance to a subject S by a TOF (Time Of Flight) method. The distance measurement device 1000 includes the light-emitting element 10. The distance measurement device 1000 includes, for example, the light-emitting element 10, a light-receiving device 125, lenses 128 and 138, a signal processing unit 145, a control unit 155, a display unit 165, and a storage unit 175.

[0188] The light receiving device 125 receives light emitted from the light emitting element 10 and reflected by the subject S (object). That is, the light receiving device 125 detects the light reflected by the subject S. The lens 128 is a lens, such as a collimating lens, for converting the light emitted from the light emitting element 10 into parallel light. The lens 138 is a lens, such as a condensing lens, for collecting the light reflected by the subject S and guiding it to the light receiving device 125.

[0189] The signal processing unit 145 is a circuit for generating a signal corresponding to the difference between the signal input from the light receiving device 125 and the reference signal input from the control unit 155. The control unit 155 is configured to include, for example, a time-to-digital converter (TDC). The reference signal may be a signal input from the control unit 155 or an output signal from a detection unit that directly detects the output of the light emitting element 10. The control unit 155 is, for example, a processor that controls the light emitting element 10, the light receiving device 125, the signal processing unit 145, the display unit 165, and the storage unit 175. The control unit 155 is a circuit that measures the distance to the subject S based on the signal generated by the signal processing unit 145. The control unit 155 generates a video signal for displaying information about the distance to the subject S and outputs it to the display unit 165. The display unit 165 displays the information about the distance to the subject S based on the video signal input from the control unit 155. The control unit 155 stores the information about the distance to the subject S in the storage unit 175.

[0190] In this application example, instead of the light-emitting element 10, any of the light-emitting elements 10-1, 10-2, 10-3, 20, 30, 40, 50, 60, 70, 80, 90, 100, 115, 120, 130, 140, 150, 160, 170, and the light-emitting and receiving device 180 can also be applied to the distance measurement device 1000.

[0191] 22. Example in which distance measuring device is mounted on a moving body> FIG. 40 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving body control system to which the technology according to the present disclosure can be applied.

[0192] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 40, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 12053.

[0193] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0194] The body system control unit 12020 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0195] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, a distance measurement device 12031 is connected to the outside-vehicle information detection unit 12030. The distance measurement device 12031 includes the above-described distance measurement device 1000. The outside-vehicle information detection unit 12030 causes the distance measurement device 12031 to measure the distance to an object outside the vehicle (subject S) and acquires the distance data obtained thereby. The outside-vehicle information detection unit 12030 may perform object detection processing for people, cars, obstacles, signs, etc. based on the acquired distance data.

[0196] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

[0197] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0198] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0199] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching from high beams to low beams.

[0200] The audio / video output unit 12052 transmits at least one of audio and video output signals to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle of information. In the example of Fig. 40, the output devices are exemplified by an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0201] FIG. 41 is a diagram showing an example of the installation position of the distance measurement device 12031.

[0202] In FIG. 41, a vehicle 12100 has distance measurement devices 12101, 12102, 12103, 12104, and 12105 as a distance measurement device 12031.

[0203] Distance measuring devices 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of vehicle 12100. Distance measuring device 12101 provided on the front nose and distance measuring device 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire data ahead of vehicle 12100. Distance measuring devices 12102 and 12103 provided on the side mirrors mainly acquire data on the sides of vehicle 12100. Distance measuring device 12104 provided on the rear bumper or back door mainly acquires data behind vehicle 12100. The forward data acquired by distance measuring devices 12101 and 12105 is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, etc.

[0204] 41 shows an example of the detection ranges of the distance measuring devices 12101 to 12104. Detection range 12111 indicates the detection range of the distance measuring device 12101 provided on the front nose, detection ranges 12112 and 12113 indicate the detection ranges of the distance measuring devices 12102 and 12103 provided on the side mirrors, respectively, and detection range 12114 indicates the detection range of the distance measuring device 12104 provided on the rear bumper or back door.

[0205] For example, based on the distance data obtained from the distance measuring devices 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the detection ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which runs autonomously without relying on driver operation.

[0206] For example, based on the distance data obtained from the distance measuring devices 12101 to 12104, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0207] The above describes an example of a mobile object control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the distance measurement device 12031 of the above-described configuration.

[0208] The present technology may also be configured as follows: (1) A light-emitting device comprising: a substrate; a laminated structure disposed on the substrate, the laminated structure including a plurality of layers including a light-emitting layer; and an intermediate structure disposed between the substrate and the laminated structure, the intermediate structure including a layer having lattice distortion. (2) The light-emitting device according to claim 1, wherein the layer having lattice distortion guides dislocations from the substrate in a lateral direction. (3) The light-emitting device according to claim 1, wherein the lattice constant of the layer having lattice distortion is different from the lattice constant of the substrate. (4) The light-emitting device according to any one of (1) to (3), wherein the absolute value of the difference between the lattice constant of the layer having lattice distortion and the lattice constant of the substrate is 0.41 Å or less. (5) The light-emitting device according to any one of (1) to (4), wherein the layer having lattice distortion includes a III-V compound semiconductor. (6) The light-emitting device according to any one of (1) to (5), wherein the layer having lattice distortion includes at least two of Al, Ga, and In, and at least one of P and As. (7) The light-emitting device according to any one of (1) to (6), wherein the layer having lattice distortion contains an n-type compound semiconductor or a p-type compound semiconductor. (8) The light-emitting device according to (7), wherein the layer having lattice distortion contains any one of Si, Se, Te, and Ge as an n-type impurity when it contains an n-type compound semiconductor, and any one of C, Mg, Zn, B, and Be as a p-type impurity when it contains a p-type compound semiconductor. (9) The light-emitting device according to any one of (1) to (8), wherein the substrate is any one of a GaAs substrate, an InP substrate, a GaN substrate, a Si substrate, a Ge substrate, an SOI substrate, and a GOI substrate. (10) The light-emitting device according to any one of (1) to (9), wherein the substrate includes a semi-insulating substrate or an insulating substrate. (11) The substrate contains an impurity, and the impurity concentration of the substrate is 1×10 16 / cm 3 1x10 or more 19 / cm 3(12) The light-emitting device according to any one of (1) to (10), which is as follows: (12) The light-emitting device according to (1) to (11), wherein the intermediate structure includes a plurality of layers having the lattice distortion; (13) The light-emitting device according to (12), wherein the intermediate structure includes a buffer layer disposed between the layers having the lattice distortion; (14) The light-emitting device according to any one of (1) to (13), wherein the intermediate structure includes a buffer layer disposed between the layer having the lattice distortion and the stacked structure; (15) The light-emitting device according to any one of (1) to (14), wherein the intermediate structure includes a buffer layer disposed between the layer having the lattice distortion and the substrate; (16) The light-emitting device according to any one of (1) to (15), wherein the intermediate structure has a composition gradient and / or a carrier concentration gradient; (17) The light-emitting device according to any one of (1) to (16), wherein the thickness of the layer having lattice distortion is equal to or less than a critical film thickness. (18) The light-emitting device according to any one of (1) to (17), wherein the lattice strain is tensile strain or compressive strain. (19) The carrier concentration of the layer having the lattice strain is 8×10 17 / cm 3The light-emitting device according to any one of (1) to (18), wherein the stacked structure includes a reflector disposed on the side of the light-emitting layer opposite to the intermediate structure side, and emits light to the side of the substrate opposite to the intermediate structure side. (21) The light-emitting device according to (13), wherein the buffer layer has a lattice constant that is the same as that of the substrate or closer to that of the substrate than the lattice constant of the layer having lattice distortion. (22) The light-emitting device according to (14), wherein the buffer layer has a lattice constant between that of the layer having lattice distortion and that of a layer adjacent to the buffer layer among the plurality of layers. (23) The light-emitting device according to (15), wherein the buffer layer has a lattice constant between that of the layer having lattice distortion and that of the substrate. (24) The light-emitting device according to any one of (1) to (23), wherein the intermediate structure includes a plurality of layers having lattice distortion and at least one buffer layer, and the layers having lattice distortion and the buffer layers are alternately arranged. (25) The light-emitting element according to (24), wherein the buffer layer is thicker than the layer having lattice distortion. (26) The light-emitting element according to (24) or (25), wherein the at least one buffer layer is a plurality of buffer layers, and the buffer layers not disposed between the layers having lattice distortion are thicker than the buffer layers disposed between the layers having lattice distortion. (27) A light-emitting and receiving device comprising: the light-emitting element according to any one of (1) to (26); and a light-receiving element provided on a substrate of the light-emitting element. (28) An electronic device comprising the light-emitting element according to any one of (1) to (26). (29) An electronic device comprising the light-emitting and receiving device according to (27).

[0209] 10, 10-1, 10-2, 10-3, 20, 30, 40, 50, 60, 70, 80, 90, 100, 11, 120, 130, 140, 150, 160, 170: Light-emitting element 101: Substrate 102: Buffer layer 102A: First buffer layer 102B: Second buffer layer 102C: Third buffer layer 103: Defect propagation suppression layer (layer having lattice distortion) 103A: First defect propagation suppression layer (layer having lattice distortion) 103B: Second defect propagation suppression layer (layer having lattice distortion) 103C: Third defect propagation suppression layer (layer having lattice distortion) 107: Light-emitting layer 108: Second semiconductor multilayer film reflector (part of reflector) 110: Dielectric multilayer film reflector (part of reflector) 111: Metal reflector (part of reflector) LS: Laminated structure IS: intermediate structure

Claims

1. A light-emitting element comprising: a substrate; a laminated structure disposed on the substrate, the laminated structure having a plurality of layers including a light-emitting layer; and an intermediate structure disposed between the substrate and the laminated structure, the intermediate structure including a layer having lattice distortion.

2. The light-emitting device according to claim 1, wherein the layer having lattice distortion guides dislocations from the substrate in the lateral direction.

3. The light-emitting device according to claim 1, wherein the lattice constant of the layer having lattice distortion is different from the lattice constant of the substrate.

4. The light-emitting device according to claim 3, wherein the absolute value of the difference between the lattice constant of the layer having lattice distortion and the lattice constant of the substrate is 0.41 Å or less.

5. The light-emitting device according to claim 1, wherein the layer having lattice distortion includes a III-V compound semiconductor.

6. The light-emitting device according to claim 1, wherein the layer having a lattice distortion contains at least two of Al, Ga, and In, and at least one of P and As.

7. The light-emitting device according to claim 1, wherein the layer having lattice distortion includes an n-type compound semiconductor or a p-type compound semiconductor.

8. The light-emitting device according to claim 7, wherein the layer having lattice distortion contains, when it contains an n-type compound semiconductor, any one of Si, Se, Te, or Ge as an n-type impurity, or when it contains a p-type compound semiconductor, any one of C, Mg, Zn, B, or Be as a p-type impurity.

9. The light-emitting device according to claim 1, wherein the substrate is any one of a GaAs substrate, an InP substrate, a GaN substrate, a Si substrate, a Ge substrate, an SOI substrate, and a GOI substrate.

10. The light-emitting device of claim 1, wherein the substrate comprises a semi-insulating substrate or an insulating substrate.

11. The substrate contains impurities, and the impurity concentration of the substrate is 1×10 16 / cm 3 1x10 or more 19 / cm 3 2. The light-emitting device of claim 1, wherein:

12. The light-emitting device according to claim 1, wherein the intermediate structure includes a plurality of layers having the lattice distortion.

13. The light-emitting device according to claim 12, wherein the intermediate structure includes a buffer layer disposed between the layers having the lattice distortion.

14. The light-emitting device according to claim 1, wherein the intermediate structure includes a buffer layer disposed between the layer having lattice distortion and the stacked structure.

15. The light-emitting device of claim 1, wherein the intermediate structure includes a buffer layer disposed between the lattice-strained layer and the substrate.

16. The light-emitting device according to claim 1, wherein the intermediate structure has a composition gradient and / or a carrier concentration gradient.

17. The light-emitting device according to claim 1, wherein the thickness of the layer having lattice distortion is equal to or less than a critical film thickness.

18. The light-emitting device according to claim 1, wherein the lattice strain is tensile or compressive.

19. The carrier concentration of the layer having the lattice distortion is 8×10 17 / cm 3 The light-emitting device according to claim 1 .

20. The light-emitting device according to claim 19, wherein the laminated structure includes a reflector disposed on the side of the light-emitting layer opposite to the intermediate structure side, and emits light to the side of the substrate opposite to the intermediate structure side.

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