Surface light emitting element

Abstract

In the present invention, the effective refractive index difference in the oxidation shrinkage layer is increased while suppressing the occurrence of cracks. A surface light emitting element according to the present technology includes: a first structure including a first semiconductor structure; a second structure including a second semiconductor structure and laminated with the first structure; at least one light emitting layer disposed between the first structure and the second structure; and a plurality of oxidation shrinkage layers laminated to each other and laminated together with the light emitting layer between a first surface and a second surface, the first surface being a surface of the first structure on a side opposite to the second structure side, and the second surface being a surface of the second structure on a side opposite to the first structure side. The plurality of oxidation shrinkage layers include at least one predetermined oxidation shrinkage layer in which the center position in the thickness direction does not coincide with the node position in the standing wave of the electric field of the emitted light.

Description

Surface-emitting elements Technical Field

[0001] The technology disclosed herein (hereinafter also referred to as "the technology") relates to surface light-emitting elements. Background Technology

[0002] Traditionally, surface-emitting elements capable of producing surface emission output, such as surface-emitting lasers and light-emitting diodes, are known.

[0003] In conventional surface-emitting elements, there are those that include an oxide confinement layer in which a high-refractive-index non-oxidized region is surrounded by a low-refractive-index oxidized region (see, for example, Patent Document 1 and Patent Document 2).

[0004] In traditional surface-emitting diodes (SEDs), there is a possibility that the formation of an oxide confinement layer can cause cracks.

[0005] Reference List

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2009-206480

[0008] Patent Document 2: Japanese Patent Application Publication No. 2005-259951 Summary of the Invention

[0009] The problem to be solved by the present invention

[0010] However, traditional surface-emitting diodes (SEDs) do not mention increasing the effective refractive index contrast in the oxide confinement layer while suppressing crack formation.

[0011] Therefore, the main objective of this technology is to provide a surface-emitting element that can increase the effective refractive index contrast in the oxide confinement layer while suppressing crack formation.

[0012] Solution to the problem

[0013] This technology provides a surface-emitting element, comprising: a first structure including a first semiconductor structure; a second structure including a second semiconductor structure, the second structure being stacked on the first structure; at least one light-emitting layer disposed between the first structure and the second structure; and a plurality of oxide confinement layers disposed between a first surface and a second surface, the first surface being the surface of the first structure away from the second structure, the second surface being the surface of the second structure away from the first structure, the plurality of oxide confinement layers being stacked together with the light-emitting layer and stacked on top of each other, wherein the plurality of oxide confinement layers includes at least one predetermined oxide confinement layer, the center position of the at least one predetermined oxide confinement layer in the thickness direction not being consistent with any node position of the standing wave of the electric field of the emitted light.

[0014] The locations other than the center of the predetermined oxide confinement layer can be consistent with the node locations.

[0015] The predetermined oxide confinement layer can be offset from the node position closest to the center position throughout the entire thickness direction.

[0016] Multiple oxide confinement layers may include at least two predetermined oxide confinement layers.

[0017] Multiple oxide confinement layers may include oxide confinement layers whose center location coincides with the node location.

[0018] Where t represents the distance between the center position and the node position closest to the center position, the distance between the center positions in the thickness direction of the light-emitting layer can be represented by (2k-1)λ / 4+t or (2k-1)λ / 4-t, where k is a natural number.

[0019] The plurality of oxide confinement layers may include: at least one first oxide confinement layer disposed on a first surface side relative to the light-emitting layer; and at least one second oxide confinement layer disposed on a second surface side relative to the light-emitting layer, wherein the first oxide confinement layer and / or the second oxide confinement layer may correspond to a predetermined oxide confinement layer.

[0020] There may be at least two predetermined oxide confinement layers, and each of the first oxide confinement layer and the second oxide confinement layer may correspond to the predetermined oxide confinement layer.

[0021] The center position of the first oxide confinement layer in the thickness direction can be located on one of the first surface side and the second surface side of the node position closest to the center position, and the center position of the second oxide confinement layer in the thickness direction can be located on the other of the first surface side and the second surface side of the node position closest to the center position.

[0022] Where L1 represents the distance between the center position in the thickness direction of the first oxide confinement layer and the center position in the thickness direction of the light-emitting layer, L2 represents the distance between the center position in the thickness direction of the second oxide confinement layer and the center position in the thickness direction of the light-emitting layer, t1 represents the distance between the center position in the thickness direction of the first oxide confinement layer and the node position closest to the center position, and t2 represents the distance between the center position in the thickness direction of the second oxide confinement layer and the node position closest to the center position, which satisfies...

[0023] L1=(2n-1)λ / 4+t1 and L2=(2m-1)λ / 4+t2

[0024] or

[0025] L1=(2n-1)λ / 4-t1 and L2=(2m-1)λ / 4-t2

[0026] Where n and m are natural numbers.

[0027] It is possible to satisfy t1=t2.

[0028] The distance between the center position of the first oxide confinement layer in the thickness direction and the center position of the light-emitting layer in the thickness direction can be equal to the distance between the center position of the second oxide confinement layer in the thickness direction and the center position of the light-emitting layer in the thickness direction.

[0029] One of the first oxide confinement layer and the second oxide confinement layer may correspond to a predetermined oxide confinement layer.

[0030] The center position in the thickness direction of one of the first oxide confinement layer and the second oxide confinement layer may be located on the first surface side or the second surface side of the node position closest to the center position, and the center position in the thickness direction of the other of the first oxide confinement layer and the second oxide confinement layer may coincide with the node position.

[0031] Where L1 represents the distance between the center position in the thickness direction of one of the first oxide confinement layer and the center position in the thickness direction of the light-emitting layer, L2 represents the distance between the center position in the thickness direction of the other of the first oxide confinement layer and the center position in the thickness direction of the light-emitting layer, and t represents the distance between the center position in the thickness direction of one of the first oxide confinement layer and the node position closest to the center position, and satisfies

[0032] L1=(2n-1)λ / 4+t and L2=(2m-1)λ / 4

[0033] or

[0034] L1=(2n-1)λ / 4-t and L2=(2m-1)λ / 4

[0035] Where n and m are natural numbers.

[0036] The distance between the center of the first oxide confinement layer in the thickness direction and the center of the light-emitting layer in the thickness direction may be different from the distance between the center of the second oxide confinement layer in the thickness direction and the center of the light-emitting layer in the thickness direction.

[0037] Each of the plurality of oxide confinement layers may include: a non-oxidized region; and an oxidized region surrounding the non-oxidized region, wherein the non-oxidized region may include AlAs or Al xGa 1-x As (0.8≤x≤1).

[0038] At least one light-emitting layer may include a plurality of light-emitting layers stacked on top of each other, and the surface light-emitting element may further include a tunnel junction layer disposed between at least two adjacent light-emitting layers forming a pair among the plurality of light-emitting layers.

[0039] The predetermined oxide confinement layer can be arranged between one of the two adjacent light-emitting layers and the tunnel junction layer.

[0040] The predetermined position in the thickness direction of the tunnel layer can coincide with the node position. Attached Figure Description

[0041] Figure 1 is a cross-sectional view of the surface-emitting laser of Comparative Example 1.

[0042] Figure 2 is a cross-sectional view of the surface-emitting laser of Comparative Example 2.

[0043] Figure 3 is a cross-sectional view of the surface-emitting laser of Comparative Example 3.

[0044] Figure 4 is a cross-sectional view of a surface-emitting element according to Embodiment 1 of the present technology.

[0045] Figure 5 is a plan view of a surface-emitting element according to Embodiment 1 of the present technology.

[0046] Figure 6 is a partially enlarged view showing the mesa extracted from the surface-emitting element shown in Figure 4.

[0047] Figure 7 is a flowchart illustrating an embodiment of a method for manufacturing a surface-emitting element according to Embodiment 1 of the present technology.

[0048] Figure 8 is a cross-sectional view of each process of an embodiment of the method for manufacturing a surface-emitting element according to Embodiment 1 of the present technology.

[0049] Figure 9 is a cross-sectional view of each process of an embodiment of the method for manufacturing a surface-emitting element according to Embodiment 1 of the present technology.

[0050] Figure 10 is a cross-sectional view of each process of an embodiment of the method for manufacturing a surface light-emitting element according to Embodiment 1 of the present technology.

[0051] Figure 11 is a cross-sectional view of each process of an embodiment of the method for manufacturing a surface light-emitting element according to Embodiment 1 of the present technology.

[0052] Figure 12 is a cross-sectional view of each process of an embodiment of the method for manufacturing a surface light-emitting element according to Embodiment 1 of the present technology.

[0053] Figure 13 is a cross-sectional view of each process of an embodiment of the method for manufacturing a surface light-emitting element according to Embodiment 1 of the present technology.

[0054] Figure 14 is a cross-sectional view of each process of an embodiment of the method for manufacturing a surface light-emitting element according to Embodiment 1 of the present technology.

[0055] Figure 15 is a cross-sectional view of each process of an embodiment of the method for manufacturing a surface light-emitting element according to Embodiment 1 of the present technology.

[0056] Figure 16 is a partially enlarged view showing the mesa extracted from the surface light-emitting element of Embodiment 2 according to the present technology.

[0057] Figure 17 is a cross-sectional view of a surface-emitting element according to Embodiment 3 of the present technology.

[0058] Figure 18 is a partially enlarged view showing the mesa extracted from the surface-emitting element shown in Figure 17.

[0059] Figure 19 is a cross-sectional view of a surface-emitting element according to Embodiment 4 of the present technology.

[0060] Figure 20 is a partially enlarged view showing the mesa extracted from the surface-emitting element shown in Figure 19.

[0061] Figure 21 is a cross-sectional view of a surface-emitting element according to Embodiment 5 of the present technology.

[0062] Figure 22 is a cross-sectional view of a surface-emitting element according to Embodiment 6 of the present technology.

[0063] Figure 23 is a partially enlarged view showing the mesa extracted from the surface-emitting element shown in Figure 22.

[0064] Figure 24 is a partial enlarged view showing the mesa extracted from the surface light-emitting element of Embodiment 7 according to the present technology.

[0065] Figure 25 is a partial enlarged view showing the mesa extracted from the surface light-emitting element of Embodiment 8 according to the present technology.

[0066] Figure 26 is a partially enlarged view showing the mesa extracted from the surface light-emitting element of Embodiment 9 according to the present technology.

[0067] Figure 27 is a partial enlarged view showing the mesa extracted from the surface light-emitting element of Embodiment 10 according to the present technology.

[0068] Figure 28 is a partially enlarged view showing the mesa extracted from the surface light-emitting element of Embodiment 11 according to the present technology.

[0069] Figure 29 is a partially enlarged view showing the mesa extracted from the surface light-emitting element of Embodiment 12 according to the present technology.

[0070] Figure 30 is a partial enlarged view showing the mesa extracted from the surface light-emitting element of Embodiment 13 according to the present technology.

[0071] Figure 31 is a diagram (part 1) illustrating the function of a surface-emitting element according to Embodiment 1 of the present invention.

[0072] Figure 32 is a diagram (part 2) illustrating the function of the surface light-emitting element of Embodiment 1 according to the present technology.

[0073] Figure 33 is a cross-sectional view showing the mesa extracted from the surface light-emitting element of a modified example 1 according to the present invention.

[0074] Figure 34 is a cross-sectional view showing the mesa extracted from the surface light-emitting element of Modified Example 2 of the embodiment according to the present technology.

[0075] Figure 35 is a plan view showing a configuration embodiment of a surface-emitting element to which this technology can be applied.

[0076] Figure 36A is a cross-sectional view taken along line XX in Figure 35. Figure 36B is a cross-sectional view taken along line YY in Figure 35.

[0077] Figure 37 is a diagram illustrating an embodiment of the application of a surface-emitting element to a distance measuring device according to Embodiment 1 of the present technology.

[0078] Figure 38 is a block diagram illustrating a schematic configuration embodiment of a vehicle control system.

[0079] Figure 39 is an explanatory diagram showing an embodiment of the installation position of the distance measuring device. Detailed Implementation

[0080] Preferred embodiments of the present technology will be described in detail below with reference to the accompanying drawings. Note that components with substantially the same functional configuration are indicated by the same reference numerals in this specification and the drawings, and therefore redundant descriptions are omitted. The embodiments described below are representative embodiments of the present technology and are not intended to be construed as narrowly limiting the scope of the present technology. Even if a surface-emitting element according to the present technology is described in this specification as exhibiting multiple effects, the surface-emitting element according to the present technology only needs to exhibit at least one effect. The effects described in this specification are merely illustrative and are not intended to be construed as limiting, and other effects may also be achieved.

[0081] Furthermore, it will be described in the following order.

[0082] 0. Introduction

[0083] 1. Surface-emitting element according to Embodiment 1 of this technology

[0084] 2. Surface-emitting element according to Embodiment 2 of this technology

[0085] 3. Surface-emitting element according to Embodiment 3 of this technology

[0086] 4. Surface-emitting element according to Embodiment 4 of this technology

[0087] 5. Surface-emitting element according to Embodiment 5 of this technology

[0088] 6. Surface-emitting element according to Embodiment 6 of this technology

[0089] 7. Surface-emitting element according to Embodiment 7 of the present technology

[0090] 8. Surface-emitting element according to embodiment 8 of the present technology

[0091] 9. Surface-emitting element according to Embodiment 9 of the present technology

[0092] 10. Surface-emitting element according to Embodiment 10 of the present technology

[0093] 11. Surface-emitting element according to Embodiment 11 of the present technology

[0094] 12. Surface-emitting element according to Embodiment 12 of the present technology

[0095] 13. Surface-emitting element according to embodiment 13 of the present technology

[0096] 14. Variations of this technology

[0097] 15. Configuration examples of surface-emitting lasers to which this technology can be applied

[0098] 16. Examples of applications of electronic devices

[0099] 17. Examples of applying surface-emitting elements in distance measuring devices

[0100] 18. An embodiment of a distance measuring device mounted on a moving body

[0101] <1. Introduction>

[0102] Surface-emitting elements such as surface-emitting lasers (VCSELs) and light-emitting diodes (LEDs) are used for a variety of applications, taking advantage of features such as compact size and long lifespan. Among them, VCSELs, in particular, have advantages such as ultra-compact size and high-speed operation, and are actively used as light sources for optical communication and rangefinders.

[0103] In the surface-emitting laser C1 of Comparative Example 1 shown in Figure 1, a first distributed Bragg reflector (DBR) 2, a first spacer layer 3, an active layer 4, a second spacer layer 6, an oxide confinement layer 5, a second distributed Bragg reflector (DBR) 7, and a contact layer 8 are stacked on a substrate 1 in this order. An electrode 9 is formed on the back side of the substrate 1, and an electrode 10 is formed on the surface of the contact layer 8. The first spacer layer 3, the active layer 4, the second spacer layer 6, the oxide confinement layer 5, the second DBR 7, and the contact layer 8 constitute a mesa. The oxide confinement layer 5 is formed by partially oxidizing a pre-oxidized layer (semiconductor layer) as a material from the side towards the center. The presence of the oxide confinement layer allows control of the current distribution in the active layer 4, producing effects such as reducing the threshold current and improving the slope efficiency.

[0104] Traditional VCSELs typically include a single oxide confinement layer, but VCSELs including multiple oxide confinement layers exhibit further improvements in emission efficiency. Specifically, VCSELs with a multi-junction (MJ) structure with multiple active layers (MJ-VCSELs) preferably include an oxide confinement layer disposed adjacent to each active layer. For example, in the case of a dual-stacked MJ-VCSEL, a device including two oxide confinement layers can improve emission efficiency compared to a device including a single oxide confinement layer.

[0105] Oxide confinement layers also contribute to lateral optical confinement. The oxide region of the oxide confinement layer contains aluminum oxide (AlxOy) and has a lower refractive index than the semiconductor layer used as the non-oxide region. This configuration produces an effective lateral refractive index contrast Δn in the mesa, thereby confining light to the center of the mesa. Typically, Δn is minimized by aligning the center position of the oxide confinement layer in the thickness direction with the node position of the standing wave generated in the resonator. Because there is a correlation between Δn and numerical aperture (NA), it is necessary to control the design value of Δn to obtain the desired NA in the oxide confinement layer. Various suggestions have been made regarding the arrangement and shape of the oxide confinement layer to control Δn. Note that NA is known to be related to far-field modes (FFP). "Effective refractive index contrast" refers to the refractive index contrast actually experienced by light propagating through the resonator, also known as "equivalent refractive index contrast".

[0106] For example, in the surface-emitting laser C2 of Comparative Example 2 shown in Figure 2, an oxide confinement layer 5 is provided whose surface is tilted away from the active layer 4. For the basic transverse mode, the oxide confinement layer 5 satisfies the condition that the center position of the oxide region in the thickness direction coincides with the node position in the standing wave distribution, and for higher-order transverse modes, it satisfies the condition that the center position of the oxide region in the thickness direction is shifted from the node position in the standing wave distribution in the positive direction. As a result, the oscillation threshold gain for the basic transverse mode can be kept low, while only the oscillation threshold gain for the higher-order transverse modes can be increased, thereby achieving high-power oscillation in the basic transverse mode. Note that in Figure 2, reference numerals 11, 12, and 13 represent wiring, insulating film, and bulk insulating material, respectively.

[0107] For example, the surface-emitting laser C3 of Comparative Example 3 shown in FIG3 includes an oxide confinement layer 5 formed by oxidation and a mode adjustment section 14. Current flows from the electrode 10 to the active layer 4, and no current flows through the mode adjustment section 14, thereby allowing amplification of the oxide region of the mode adjustment section 14. As a result, higher-order modes can be suppressed, and high-power fundamental transverse modes can be realized.

[0108] All surface-emitting lasers C1 to C3 in Comparative Examples 1 to 3 described above are designed to suppress higher-order transverse modes and achieve high-power fundamental transverse modes corresponding to reduced NA. The inventors have discovered that while techniques for stably achieving low NA have been proposed to date, techniques for stably achieving high NA have not yet been developed. This is the inventors' first new discovery.

[0109] The inventors have further investigated and discovered that, in order to achieve high refractive index contrast (NA), it is necessary to increase the effective refractive index contrast (Δn) by increasing the overlap between the standing wave and the oxide confinement layer, and there are approximately two methods for this. This is the inventors' second new discovery. One of these methods is to increase the thickness of the oxide confinement layer (the former), and the other method is to shift the center position relative to the node position of the standing wave in the thickness direction of the oxide confinement layer (the latter).

[0110] The inventors discovered the following problems with the former method. An oxide confinement layer is formed by oxidizing a pre-oxidized layer with an Al composition (e.g., an AlAs layer or AlGaAs layer with a high Al composition), but volume shrinkage occurs during the oxidation process. At this time, the pre-oxidized layer cannot withstand the resulting internal stress, and cracks may form at the interface between the pre-oxidized layer and the upper and lower semiconductor layers. Furthermore, even if no cracks form during the oxidation process, cracks may occur during subsequent mounting processes or reliability tests. The greater the thickness of the oxide confinement layer, the higher the risk of such crack formation; therefore, for reliability, it is preferable to make the oxide confinement layer as thin as possible. This is the inventors' third new discovery.

[0111] Based on the second and third new findings mentioned above, the inventors concluded that in order to achieve a high Δn without increasing the risk of cracking, it is preferable to shift the center position of the oxide confinement layer in the thickness direction relative to the node position of the standing wave. The inventors then developed a surface-emitting element according to this technology as a surface-emitting element implementing the above-mentioned elements. According to this technology, a surface-emitting element capable of increasing the effective refractive index contrast in the oxide confinement layer while suppressing crack formation can be provided. Increasing the effective refractive index contrast in the oxide confinement layer results in a higher NA for the oxide confinement layer.

[0112] In the following, some embodiments of the surface-emitting element according to the present technology will be described in detail with reference to the accompanying drawings. In the following, in the cross-sectional views of FIG1 and other drawings, the upper side will be referred to as "upper" and the lower side will be referred to as "lower", as appropriate.

[0113] <1. Surface light-emitting element according to Embodiment 1 of the present technology>

[0114] Figure 4 is a cross-sectional view of the surface-emitting element 1000 according to Embodiment 1 of the present invention. Figure 5 is a plan view (top view) of the surface-emitting element 1000 according to Embodiment 1 of the present invention. Figure 4 is a cross-sectional view taken along line 1-1 in Figure 5.

[0115] Construction of Surface Light Emitting Devices

[0116] (Overall structure)

[0117] As an embodiment, as shown in Figures 4 and 5, the surface-emitting element 1000 of Embodiment 1 according to the present invention is a vertical-cavity surface-emitting laser (VCSEL). As an embodiment, the surface-emitting element 1000 is a front-emitting type VCSEL. As an embodiment, the surface-emitting element 1000 includes a multi-junction (MJ) structure.

[0118] As an example, the surface-emitting element 1000 is driven by a driver (driving circuit). As an example, the driver includes a power supply and a transistor that controls the switching on and off of the current supply from the power supply to the surface-emitting element 1000.

[0119] As an embodiment, the surface-emitting element 1000 includes: a first structure ST1, including a first semiconductor structure SS1; a second structure ST2, including a second semiconductor structure SS2, the second structure ST2 being stacked on the first structure ST1; a third semiconductor structure SS3, including a first light-emitting layer 103 and a second light-emitting layer 109, the third semiconductor structure SS3 being disposed between the first structure ST1 and the second structure ST2; and oxide confinement layers 105 and 111, stacked together with the first light-emitting layer 103 and the second light-emitting layer 109, and stacked on top of each other between the first surface (lower surface) of the first structure ST1 away from the second structure ST2 and the second surface (upper surface) of the second structure ST2 away from the first structure ST1. In the following, the stacking direction (vertical direction) of the first structure ST1 and the second structure ST2 is also referred to as the "stacking direction".

[0120] As an example, in addition to the first semiconductor structure SS1, the first structure ST1 includes a substrate 100 disposed on the side (lower side) of the first semiconductor structure SS1 away from the second semiconductor structure SS2.

[0121] As an example, the first semiconductor structure SS1 includes a first semiconductor multilayer reflector 101.

[0122] As an example, the second semiconductor structure SS2 includes a second semiconductor multilayer reflector 112 and a contact layer 113. The second semiconductor multilayer reflector 112 and the contact layer 113 are stacked from the substrate 100 side (bottom side) in this order.

[0123] In addition to the first light-emitting layer 103 and the second light-emitting layer 109, the third semiconductor structure SS3 includes a first cladding layer 102, a second cladding layer 104, a third cladding layer 106, a tunnel junction layer 107, a fourth cladding layer 108, and a fifth cladding layer 110. The first cladding layer 102, the second cladding layer 104, the third cladding layer 106, the tunnel junction layer 107, the fourth cladding layer 108, and the fifth cladding layer 110 are stacked from the substrate 100 side (bottom side) in this order.

[0124] A first light-emitting layer 103 is disposed between a first cladding layer 102 and a second cladding layer 104. A tunnel junction layer 107 is disposed between a third cladding layer 106 and a fourth cladding layer 108. A second light-emitting layer 109 is disposed between a fourth cladding layer 108 and a fifth cladding layer 110. An oxide confinement layer 105 is disposed between a second cladding layer 104 and a third cladding layer 106. An oxide confinement layer 111 is disposed between a fifth cladding layer 110 and a second semiconductor multilayer reflector 112. The first cladding layer 102 and the fourth cladding layer 108 each comprise an n-type semiconductor. The second cladding layer 104, the third cladding layer 106, and the fifth cladding layer 110 each comprise a p-type semiconductor.

[0125] That is, the tunneling layer 107 is disposed between the stacked first light-emitting layer 103 and second light-emitting layer 109. The oxide confinement layer 105 is disposed between the first light-emitting layer 103 and the tunneling layer 107.

[0126] The oxide confinement layer 105 primarily defines the light-emitting region of the first light-emitting layer 103. The emitting region of the first light-emitting layer 103 is the region in which current is injected (current injection region) and is the region that emits light.

[0127] The second oxide confinement layer 111 primarily defines the emission region of the second light-emitting layer 109. The light-emitting region of the second light-emitting layer 109 is the region in which current is injected (current injection region) and is the region that emits light.

[0128] As described above, in the surface light-emitting element 1000, as an embodiment, a first semiconductor multilayer reflector 101, a first cladding layer 102, a first light-emitting layer 103, a second cladding layer 104, an oxide confinement layer 105, a third cladding layer 106, a tunnel junction layer 107, a fourth cladding layer 108, a second light-emitting layer 109, a fifth cladding layer 110, an oxide confinement layer 111, a second semiconductor multilayer reflector 112, and a contact layer 113 are sequentially stacked on the substrate 100 from the substrate 100 side (bottom side).

[0129] The surface-emitting element 1000 has a dual heterostructure, wherein the first light-emitting layer 103 is sandwiched between a first cladding layer 102 and a second cladding layer 104 with different conductivity types in the stacking direction to allow holes and electrons to undergo luminescent recombination (radiative recombination).

[0130] The surface-emitting element 1000 has a dual heterostructure, wherein the second light-emitting layer 109 is sandwiched between a fourth cladding layer 108 and a fifth cladding layer 110 with different conductivity types in the stacking direction, so as to allow holes and electrons to undergo luminescent recombination (radiative recombination).

[0131] In the surface-emitting element 1000, a third semiconductor structure SS3, including a first light-emitting layer 103 and a second light-emitting layer 109, and a first semiconductor multilayer reflector 101 and a second semiconductor multilayer reflector 112 sandwiched between the third semiconductor structure SS3 along the stacking direction constitute a resonator. The surface-emitting element 1000 emits laser light toward the second surface (upper side) of the second structure ST2.

[0132] In the surface-emitting element 1000, as an embodiment, a second semiconductor structure SS2 and a third semiconductor structure SS3, along with oxide confinement layers 105 and 111, constitute a mesa M1. Here, the mesa M1 extends upward from the first semiconductor structure SS1. The mesa M1 is also referred to as a "light-emitting mesa". Here, the mesa M1 has a circular shape in a plan view (see Figure 2), but is not limited to this shape and can have different shapes, such as elliptical or polygonal shapes. As an embodiment, the mesa M1 has a diameter of tens of μm (e.g., 20 μm to 30 μm).

[0133] On the top of the platform M1 (specifically, on the contact layer 113), an annular (e.g., ring-shaped) anode electrode 115 (p-side electrode) is provided to surround the emission area of ​​each light-emitting layer in a plan view.

[0134] As an embodiment, the mesa M1 and the region of the first semiconductor structure SS1 surrounding the mesa M1 are covered with an insulating film 116. The insulating film 116 has a contact hole 116a, in which an anode electrode 115 is disposed. An anode wiring 150 is disposed on the insulating film 116 to contact the anode electrode 115. The anode wiring 150 is provided with an opening 150a through which the insulating film 116 on the inner diameter side of the anode electrode 115 is exposed, and the opening 150a serves as a emitter port. The anode electrode 115 is electrically connected to the anode side of the driver. Note that the anode wiring 150 may expose the inner diameter portion of the anode electrode 115 so that the inner diameter side of the anode electrode 115 serves as a emitter port.

[0135] For example, a planar cathode electrode 114 (n-side electrode) is disposed on the back side (lower surface) of the substrate 100. The cathode electrode 114 is electrically connected to the cathode side of the driver.

[0136] As an example, the surface light-emitting element 1000 is mounted in a coupled manner on a mounting substrate (e.g., a driving substrate with a driver, a wiring substrate connected to the driver, etc.).

[0137] (Substrate)

[0138] For example, substrate 100 includes a GaAs substrate (e.g., an n-GaAs substrate).

[0139] (First semiconductor multilayer reflector)

[0140] For example, the first semiconductor multilayer reflector 101 (semiconductor DBR) is a semiconductor multilayer reflector doped with n-type impurities and exhibits low light absorption, high reflectivity, and high conductivity. Multilayer reflectors are also called distributed Bragg reflectors (DBRs). The first semiconductor multilayer reflector 101 has a multilayer structure comprising alternating stacks of low-refractive-index layers and high-refractive-index layers, with a first or second gradient layer (composition-gradient layer) disposed between adjacent low-refractive-index layers and high-refractive-index layers. The multilayer structure includes multiple four-layer structures, each four-layer structure sequentially comprising a stack of a low-refractive-index layer, a first gradient layer, a high-refractive-index layer, and a second gradient layer. As an example, the low-refractive-index layer comprises Al. x1 Ga 1-x1 As (0 < x1 ≤ 1). The high refractive index layer contains Al. x2 Ga 1-x2 As (0 ≤ x2 < x1). The first gradient layer exhibits a continuous compositional change, starting from the composition of the low-refractive-index layer on the side in contact with the low-refractive-index layer and ending from the composition of the high-refractive-index layer on the opposite side in contact with the high-refractive-index layer. The second gradient layer exhibits a continuous compositional change, starting from the composition of the high-refractive-index layer on the side in contact with the high-refractive-index layer and ending from the composition of the low-refractive-index layer on the opposite side in contact with the low-refractive-index layer. Examples of n-type impurities (n-type dopants) used for the first semiconductor multilayer reflector 101 include Si, Se, Ge, etc. The reflectivity of the first semiconductor multilayer reflector 101 is set to be slightly higher than that of the second semiconductor multilayer reflector 112. Note that the first semiconductor multilayer reflector 101 need not include a first gradient layer and a second gradient layer.

[0141] (First coating layer)

[0142] The first coating layer 102 includes, for example, n-Al. x3 Ga 1-x3 As (0≤x3<1). The “first cladding layer” can be referred to as the “first spacer layer”. Examples of n-type impurities (n-type dopants) used for the first cladding layer 102 include Si, Se, Ge, etc.

[0143] (First luminescent layer)

[0144] As an example, the first light-emitting layer 103 comprises a compound semiconductor having a bandgap energy smaller than that of the first cladding layer 102 and the second cladding layer 104. The first light-emitting layer 103 has, for example, alternating layers of undoped In. x4 Ga 1-x4 As (0 < x4 < 1) well layer and undoped Al x5 Ga 1-x5As a stacked multi-quantum-well structure with (0 < x5 < 1) barrier layers. The first light-emitting layer 103 can have any one of a quantum well structure, a quantum wiring structure, or a quantum dot structure instead of a multi-quantum-well structure. The emission wavelength of the first light-emitting layer 103 is set to, for example, about 600 to 1100 nm. The first light-emitting layer 103 can be referred to as the "first active layer". Preferably, the center position of the first light-emitting layer 103 in the thickness direction coincides with the position of the antinode of the standing wave generated in the resonator (antinode position).

[0145] (Second coating layer)

[0146] The second coating layer 104 includes, for example, p-Al. x6 Ga 1-x6 As (0 ≤ x6 < 1). The "second coating layer" can be referred to as the "second spacer layer". Examples of p-type impurities (p-type dopants) used for the second coating layer 104 include Zn, Mg, Be, C, etc.

[0147] (Oxide confinement layer 105)

[0148] For example, oxide confinement layer 105 includes a non-oxidized region 105a and an oxidized region 105b (insulating region) surrounding the non-oxidized region 105a.

[0149] The non-oxidized region 105a corresponds to the emitting region of the first light-emitting layer 103 and serves as a current and light transmission region. For example, the non-oxidized region 105a includes p-Al x7 Ga 1-x7 As (0 < x7 ≤ 1), and preferably x7 ≥ 0.8, and more preferably x7 ≥ 0.9. Examples of P-type impurities (P-type dopants) as non-oxidized regions 105a include Zn, Mg, Be, C, etc.

[0150] As an example, the oxidized region 105b is a ring-shaped region surrounding the unoxidized region 105a in a plan view. The oxidized region 105b has a higher resistivity and a lower refractive index than the unoxidized region 105a and serves as a current and optical confinement region. The oxidized region 105b is, for example, composed of Al₂O₃ (alumina), for example by selectively oxidizing a pre-oxidized layer 105S (e.g., p-Al) with a high Al composition from the side. x7 Ga 1-x7 It is formed by As layer (0≤x7≤1)).

[0151] The thickness of the oxide confinement layer 105 is preferably λ / 2 or less, more preferably λ / 4 or less, more preferably λ / 8 or less, and even more preferably λ / 16 or less. Here, λ represents the oscillation wavelength of the resonator.

[0152] (Third coating layer)

[0153] For example, the third coating layer 106 includes p-Al x8 Ga 1-x8 As (0 ≤ x8 < 1). The "third coating layer" may be referred to as the "third spacer layer". Examples of p-type impurities (p-type dopants) used for the third coating layer 106 include Zn, Mg, Be, C, etc.

[0154] (Tunnel layer)

[0155] The tunnel junction layer 107 has the function of allowing current from the second light-emitting layer 109 to flow to the first light-emitting layer 103 through the tunneling effect while maintaining the current value. Preferably, a predetermined position (e.g., a center position) in the thickness direction of the tunnel junction layer 107 coincides with the node position of the standing wave. The tunnel junction layer 107 has, for example, a stacked structure including a highly doped p-type layer (p++ layer) and a highly doped n-type layer (n++ layer). The highly doped p-type layer includes, for example, GaAs or InGaAs containing p-type impurities (such as high-concentration carbon (C)), and the highly doped n-type layer includes, for example, GaAs or InGaAs containing n-type impurities (such as high-concentration tellurium (Te)). Here, the highly doped p-type layer is disposed on the substrate 100 side (lower side) of the highly doped n-type layer.

[0156] (Fourth coating layer)

[0157] The fourth coating layer 108 includes, for example, n-Al x9 Ga 1-x9 As (0 ≤ x9 < 1). The "fourth cladding layer" can be referred to as the "fourth spacer layer". Examples of n-type impurities (n-type dopants) used for the fourth cladding layer 108 include Si, Se, Ge, etc.

[0158] (Second light-emitting layer)

[0159] As an example, the second light-emitting layer 109 comprises a compound semiconductor having a bandgap energy smaller than that of the fourth cladding layer 108 and the fifth cladding layer 110. The second light-emitting layer 109 has, for example, alternating layers of undoped In. x10 Ga 1- x10 As (0 < x10 < 1) well layer and undoped Al x11 Ga 1-x11As a stacked multi-quantum-well structure with (0 < x11 < 1) barrier layers. The second light-emitting layer 109 can have any one of a quantum well structure, a quantum wiring structure, or a quantum dot structure instead of a multi-quantum-well structure. The emission wavelength of the second light-emitting layer 109 is set to be the same as the emission wavelength of the first light-emitting layer 103 (e.g., 600 to 1100 nm). The second light-emitting layer 109 can be referred to as the "second active layer". Preferably, the center position of the second light-emitting layer 109 in the thickness direction coincides with the position of the antinode of the standing wave generated in the resonator (the position of the antinode).

[0160] (Fifth coating layer)

[0161] The fifth coating layer 110 includes, for example, p-Al x12 Ga 1-x12 As (0 ≤ x12 < 1). The "fifth cladding layer" can be referred to as the "fifth spacer layer". Examples of p-type impurities (p-type dopants) used for the fifth cladding layer 110 include Zn, Mg, Be, C, etc.

[0162] (Oxide confinement layer 111)

[0163] As an example, the oxide confinement layer 111 includes a non-oxidized region 111a and an oxidized region 111b (insulating region) surrounding the non-oxidized region 111a.

[0164] The non-oxidized region 111a corresponds to the emission region of the second light-emitting layer 109 and serves as a current and light transmission region. For example, the non-oxidized region 111a includes p-Al x13 Ga 1-x13 As (0 < x13 ≤ 1), and preferably x13 ≥ 0.8, and more preferably x13 ≥ 0.9. Examples of p-type impurities (p-type dopants) used for the non-oxidized region 111a include Zn, Mg, Be, C, etc.

[0165] As an example, the oxidized region 111b is an annular (e.g., ring-shaped) region surrounding the non-oxidized region 111a in a planar view. The oxidized region 111b has a higher resistivity and a lower refractive index than the non-oxidized region 111a and serves as a current and optical confinement region. The oxidized region 111b comprises, for example, Al₂O₃ (aluminum oxide) and is formed, for example, by selectively oxidizing a second pre-oxidized layer 111S (e.g., p-Al) with a high Al composition from the side surface. x13 Ga 1-x13 As layers (0≤x13≤1) are formed.

[0166] As an example, the non-oxidized region 111a of the oxide confinement layer 111 is located at a position corresponding to the non-oxidized region 105a of the oxide confinement layer 105. As an example, the oxide opening diameter (inner diameter of the oxidized region 111b) of the oxide confinement layer 111 is set to be the same as the oxide opening diameter (inner diameter of the oxidized region 105b) of the oxide confinement layer 105.

[0167] The thickness of the oxide confinement layer 111 is preferably λ / 2 or less, more preferably λ / 4 or less, more preferably λ / 8 or less, and even more preferably λ / 16 or less. Here, λ represents the oscillation wavelength of the resonator.

[0168] (Second semiconductor multilayer reflector)

[0169] As an example, the second semiconductor multilayer reflector 112 (semiconductor DBR) is a semiconductor multilayer reflector doped with p-type impurities, exhibiting low light absorption, high reflectivity, and high conductivity. Multilayer reflectors are also called distributed Bragg reflectors (DBRs). The second semiconductor multilayer reflector 112 has a multilayer structure comprising alternating stacks of low-refractive-index layers and high-refractive-index layers, with a first gradient layer or a second gradient layer (composite-gradient layer) disposed between adjacent low-refractive-index layers and high-refractive-index layers. The multilayer structure includes multiple four-layer structures, each four-layer structure sequentially comprising a stack of a low-refractive-index layer, a first gradient layer, a high-refractive-index layer, and a second gradient layer. For example, the low-refractive-index layer comprises Al. x14 Ga 1-x14 As (0 < x14 ≤ 1). High refractive index layers include Al. x15 Ga 1-x15 As (0 ≤ x15 < x14). The first gradient layer exhibits a continuous compositional change, starting from the composition of the low-refractive-index layer on the side in contact with the low-refractive-index layer and ending from the composition of the high-refractive-index layer on the opposite side in contact with the high-refractive-index layer. The second gradient layer exhibits a continuous compositional change, starting from the composition of the high-refractive-index layer on the side in contact with the high-refractive-index layer and ending from the composition of the low-refractive-index layer on the opposite side in contact with the low-refractive-index layer. Examples of P-type impurities (P-type dopants) in the second semiconductor multilayer reflector 112 include Zn, Mg, Be, C, etc. Note that the second semiconductor multilayer reflector 112 need not include a first gradient layer and a second gradient layer.

[0170] (Contact layer)

[0171] Contact layer 113 is a layer used for ohmic contact with anode electrode 115. Contact layer 113 is a layer highly doped with p-type impurities and includes, for example, p-Al. x16 Ga 1-x16As (0 ≤ x16 < 1). Examples of p-type impurities (p-type dopants) used for contact layer 113 include Zn, Mg, Be, C, etc.

[0172] (Insulating film)

[0173] The insulating film 116 includes, for example, a dielectric such as polyimide, SiN, SiO2 or SiON.

[0174] (Anode electrode)

[0175] For example, the anode electrode 115 comprises a non-alloy material and has, for example, a structure in which Ti, Pt and Au are stacked sequentially from the contact layer 113 side.

[0176] (Anode wiring)

[0177] As an example, the anode wiring 150 is formed by plating with Au, Ag, Cu, etc.

[0178] (Cathode electrode)

[0179] As an example, the cathode electrode 114 comprises an alloy material and, for example, has a structure in which AuGe, Ni and Au are stacked sequentially from the substrate 100 side.

[0180] (Location of the light-emitting layer and the oxide confinement layer)

[0181] Figure 6 is a partially enlarged view showing the mesa M1 extracted from the surface-emitting element 1000 shown in Figure 4. As shown in Figure 6, in an embodiment, the center position CP103 in the thickness direction of the first light-emitting layer 103 coincides with the position of the antinode of the standing wave of the electric field of the emitted light (oscillating light) (standing wave generated in the resonator). The center position CP109 in the thickness direction of the second light-emitting layer 109 coincides with the position of the antinode of the standing wave of the electric field of the emitted light (oscillating light) (standing wave generated in the resonator).

[0182] As an example, the oxide confinement layer 105 is a first oxide confinement layer disposed on the first surface side (lower side) of the first structure ST1 relative to the second light-emitting layer 109. As an example, the oxide confinement layer 111 is a second oxide confinement layer disposed on the second surface side (upper side) of the second structure ST2 relative to the second light-emitting layer 109.

[0183] As an example, the oxide confinement layer 105 is a predetermined oxide confinement layer, the center position CP105 of which in the thickness direction does not coincide with any node position (any node position) of the standing wave of the electric field of the emitted light (the standing wave generated in the resonator). Specifically, as an example, the center position CP105 in the thickness direction of the oxide confinement layer 105 is located on the first surface side (lower side) relative to the node position NP105 of the standing wave closest to the center position CP105.

[0184] As an example, the oxide confinement layer 111 is a predetermined oxide confinement layer whose center position CP111 in the thickness direction does not coincide with any node position (any node position) of the standing wave of the electric field of the emitted light (the standing wave generated in the resonator). Specifically, the center position CP111 in the thickness direction of the oxide confinement layer 111 is located on the second surface side (upper side) relative to the node position NP111 of the standing wave closest to the center position CP111. That is, the positions of the oxide confinement layers 105 and 111 are located on opposite sides relative to their respective nearest node positions.

[0185] Here, as an embodiment, the oxide confinement layer 105 (predetermined oxide confinement layer) is shifted along the entire thickness direction from the node position NP105 of the standing wave that is closest to the center position CP105 in the thickness direction. As an embodiment, the oxide confinement layer 111 (predetermined oxide confinement layer) is shifted along the entire thickness direction from the node position NP111 of the standing wave that is closest to the center position CP111 in the thickness direction.

[0186] Where t1 represents the distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the node position NP105 of the standing wave closest to the center position CP105, and L1 represents the distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the center position CP109 in the thickness direction of the second light-emitting layer 109, satisfying L1=(2n-1)λ / 4+t1, where n is a natural number. Here, 0<t1≤λ / 4 (λ represents the oscillation wavelength).

[0187] t2 represents the distance between the center position CP111 of the oxide confinement layer 111 in the thickness direction and the node position NP111 of the standing wave closest to the center position CP111. L2 represents the distance between the center position CP111 of the oxide confinement layer 111 in the thickness direction and the center position CP109 of the second light-emitting layer 109 in the thickness direction, satisfying L2 = (2m-1)λ / 4 + t2, where m is a natural number. Here, 0 < t2 ≤ λ / 4 (λ represents the oscillation wavelength).

[0188] In the embodiment shown in Figure 6, t1=t2=t (0<t≤λ / 4) and n=m=k (where k is a natural number and k=2). This indicates that the oxide confinement layers 105 and 111 are arranged symmetrically with respect to the center position CP109 in the thickness direction of the second light-emitting layer 109.

[0189] That is, the distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the center position CP109 in the thickness direction of the second light-emitting layer 109 is equal to the distance between the center position CP111 in the thickness direction of the oxide confinement layer 111 and the center position CP109 in the thickness direction of the second light-emitting layer 109.

[0190] When L3 represents the distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the center position CP103 in the thickness direction of the first light-emitting layer 103, L3 satisfies L3 = (2i-1)λ / 4 - t3 (0 < t3 ≤ λ / 4), where i is a natural number. In the embodiment shown in Figure 6, i = 2 and t3 = t.

[0191] The structural features of the aforementioned surface light-emitting element 1000 can be determined, for example, by cross-sectional analysis using a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM).

[0192] Operation of Surface Light Emitting Devices

[0193] The operation of the surface-emitting element 1000 will be described below. When a power supply voltage is applied to the surface-emitting element 1000, current flows from the anode side of the driver into the mesa M1 through the anode electrode 115. The current flowing into the mesa M1 flows sequentially through the contact layer 113 and the second semiconductor multilayer reflector 112, is confined by the oxide confinement layer 111, and then is injected into the second light-emitting layer 109 through the fifth cladding layer 110. The current injected into the second light-emitting layer 109 flows sequentially through the fourth cladding layer 108, the tunnel junction layer 107, and the third cladding layer 106, is confined by the oxide confinement layer 105, and then is injected into the first light-emitting layer 103 through the second cladding layer 104. When current is injected into each of the first light-emitting layer 103 and the second light-emitting layer 109, the first light-emitting layer 103 and the second light-emitting layer 109 emit light. The light, confined by oxide confinement layers 105 and 111 and amplified by the first light-emitting layer 103 and the second light-emitting layer 109, propagates back and forth between the first semiconductor multilayer reflector 101 and the second semiconductor multilayer reflector 112. When the oscillation condition is met, the light is emitted as a laser onto the upper surface side of the mesa M1. The current injected into the first light-emitting layer 103 flows sequentially through the first cladding layer 102, the first semiconductor multilayer reflector 101, the substrate 100, and the cathode electrode 114 to the cathode side of the driver.

[0194] Methods for Manufacturing Surface Light Emitting Devices

[0195] In the following, embodiments of the method for manufacturing the surface-emitting element 1000 will be described with reference to flowcharts such as FIG7. As a general process, firstly, a plurality of surface-emitting elements 1000 are simultaneously formed on a wafer (hereinafter referred to as "substrate 100" for convenience) that serves as the base material of the substrate 100 using a semiconductor manufacturing method of a semiconductor manufacturing apparatus. Next, the plurality of surface-emitting elements 1000, which are integrally formed into an array, are separated from each other by dicing (e.g., stealth dicing) to obtain a chip-shaped surface-emitting element 1000.

[0196] In the first step S1, a multilayer body is generated (see Figure 8). Specifically, it consists of a first semiconductor multilayer reflector 101, a first cladding layer 102, a first light-emitting layer 103, a second cladding layer 104, and a pre-oxidized layer 105S (e.g., p-Al). x7 Ga 1-x7 As layer (0≤x7≤1)), third coating layer 106, tunneling layer 107, fourth coating layer 108, second luminescent layer 109, fifth coating layer 110, pre-oxidized layer 111S (e.g., p-Al) x13 Ga 1-x13 An As layer (0 ≤ x 13 ≤ 1), a second semiconductor multilayer reflector 112, and a contact layer 113 are sequentially stacked on a substrate 100, which serves as a growth substrate, by epitaxial crystal growth such as metal-organic chemical vapor deposition (MOCVD) to form a multilayer. During the formation of the multilayer, for example, methyl organometallic gases such as trimethylaluminum (TMAl), trimethylgallium (TMGa), or trimethylindium (TMIn) and arsine (AsH3) gas are used as raw materials for the compound semiconductor; for example, silane (Si2H6) is used as a raw material for the donor impurity; and for example, carbon tetrabromide (CBr4) is used as a raw material for the acceptor impurity.

[0197] In the next step S2, a mesa is formed (see Figure 9). Specifically, first, a resist pattern for forming the mesa on the multilayer is formed by photolithography. Then, using the resist pattern as a mask, the multilayer is etched by dry etching (e.g., reactive ion etching (RIE) using a Cl-type gas). This etching is performed at least until the side surfaces of the pre-oxidized layer 105S are exposed (e.g., until the etched bottom surface coincides with the upper surface of the first semiconductor multilayer reflector 101). As a result, the mesa is formed. Afterward, the resist pattern is removed.

[0198] In the next step S3, oxide confinement layers 105 and 111 are formed (see FIG. 10). Specifically, the mesa formed on the multilayer body is exposed to a high-temperature vapor atmosphere, and Al contained in each pre-oxidized layer 105S and 111S (see FIG. 9) is selectively oxidized from the sides of the mesa. Alternatively, Al contained in each pre-oxidized layer 105S and 111S is selectively oxidized from the sides of the mesa by wet oxidation (see FIG. 9). As a result, an oxide confinement layer 105 comprising a non-oxidized region 105a surrounded by an oxidized region 105b and an oxide confinement layer 111 comprising a non-oxidized region 111a surrounded by an oxidized region 111b are formed.

[0199] In the next step S4, an insulating film 116 is formed. Specifically, firstly, the insulating film 116 is formed over the entire surface (see FIG. 11). Chemical vapor deposition (CVD) is preferably used to form the insulating film 116. The reason is that the insulating film 116 not only prevents moisture from contacting each component such as the first semiconductor multilayer reflector 101, the second semiconductor multilayer reflector 112, the oxide confinement layer 105, and the oxide confinement layer 111, but also electrically insulates each component (except for the contact layer 113) from the anode electrode 115; therefore, high conformability on the side surfaces of the mesa is required. More specifically, methods such as plasma CVD or thermal CVD can be used for the formation of the insulating film 116. In addition, spin coating or the like can be used to planarize the insulating film 116, but it is preferred to use CVD in combination before and after spin coating to improve conformability. Next, the insulating film 116 on the mesa is selectively removed by photolithography and etching to form an annular (e.g., ring-shaped) contact hole 116a (see FIG. 12) exposing a portion of the contact layer 113.

[0200] In the next step S5, an anode electrode 115 is formed (see FIG13). Specifically, for example, Ti, Pt and Au are sequentially stacked in the contact hole 116a by, for example, vacuum deposition, sputtering or the like, to form an annular (e.g., ring-shaped) anode electrode 115 in contact with the contact layer 113.

[0201] In the next step S6, the anode wiring 150 is formed (see FIG. 14). Specifically, for example, the anode wiring 150 is formed by plating, thereby contacting the anode electrode 115 and exposing the insulating film 116 on the inner diameter side of the anode electrode 115. Note that it is preferable to pre-form a seed layer on the area to be plated before performing the plating.

[0202] In the final step S7, a cathode electrode 114 is formed (see FIG. 15). Specifically, after polishing the rear surface (lower surface) of the substrate 100 to reduce the total thickness to, for example, approximately 100 μm, an alloy layer of Au and Ge (AuGe layer), a Ni layer, and an Au layer are sequentially stacked on the rear surface by, for example, vacuum deposition, sputtering, etc., to form a planar cathode electrode 114. Then, the cut portion of the insulating film 116 is removed, and the plurality of surface light-emitting elements 1000 integrally formed on the substrate 100 are separated by cutting (e.g., stealth cutting) to obtain a plurality of chip-shaped surface light-emitting elements 1000.

[0203] Effects of Surface-Emitting Devices

[0204] The effect of the surface-emitting element 1000 will be described below.

[0205] The surface light-emitting element 1000 includes a first structure ST1 containing a first semiconductor structure SS1, a second structure ST2 containing a second semiconductor structure SS2, the second structure ST2 being stacked on the first structure ST1, a first light-emitting layer 103 and a second light-emitting layer 109 disposed between the first structure ST1 and the second structure ST2, and oxide confinement layers 105 and 111 stacked together with the first light-emitting layer 103 and the second light-emitting layer 109 and stacked on top of each other between a first surface of the first structure ST1 away from the second structure ST2 and a second surface of the second structure ST2 away from the first structure ST1, and each of the oxide confinement layers 105 and 111 serves as a predetermined oxide confinement layer, the center position of which in the thickness direction is not consistent with any node position of the standing wave of the electric field of the emitted light.

[0206] In the surface-emitting element 1000, since the center position in the thickness direction of each of the oxide confinement layers 105 and 111 is not aligned with any node position of the standing wave of the electric field of the emitted light, the effective refractive index contrast Δn in each oxide confinement layer can be increased without increasing the thickness of the oxide confinement layer compared to the case where the center position is aligned with the node position. A higher Δn results in a higher NA.

[0207] As a result, the surface-emitting element 1000 enables the provision of a surface-emitting element that can increase the effective refractive index contrast Δn in each of the oxide confinement layers 105 and 111 while suppressing crack formation.

[0208] Each of the oxide confinement layers 105 and 111 is displaced from any node location of the standing wave along the entire thickness direction. This allows for a substantial increase in the effective refractive index contrast Δn in each oxide confinement layer, even when the oxide confinement layer thickness is small.

[0209] t represents the distance between the center position of each oxide confinement layer in the thickness direction and the node position of the standing wave closest to the center position. The distance between the center position of the second light-emitting layer 109 in the thickness direction and the center position CP109 is represented by (2k-1)λ / 4+t, where k is a natural number. Therefore, the center position CP109 of the second light-emitting layer 109 in the thickness direction can be made to coincide with the antinode position of the standing wave, and the center position of each oxide confinement layer in the thickness direction can be offset by a distance t from the nearest node position of the standing wave.

[0210] The center position CP105 of the oxide confinement layer 105 in the thickness direction is located on the first surface side (lower side) relative to the node position NP105 of the standing wave closest to the center position CP105, and the center position CP111 of the oxide confinement layer 111 in the thickness direction is located on the second surface side (upper side) relative to the node position NP111 of the standing wave closest to the center position CP111. In this case, since the oxide confinement layer 105 is shifted downward by a distance t from the nearest node position NP105, and the oxide confinement layer 111 is shifted upward by a distance t from the nearest node position NP111, even if the actual epitaxial film thickness deviates from the design value during manufacturing, and the oxide confinement layers 105 and 111 deviate from the standing wave, for example, by a distance u (<t) in the stacking direction (emission direction), one of the oxide confinement layers 105 and 111 approaches the nearest node position, while the other moves away from the nearest node position (see Figures 31 and 32); therefore, deviation from the design value Δn can be suppressed. This ensures high robustness relative to the design value NA. For example, in the embodiment shown in FIG31, the deviation results in the distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the nearest node position NP105 being equal to t+u, and the distance between the center position CP111 in the thickness direction of the oxide confinement layer 111 and the nearest node position NP111 being equal to tu. In the embodiment shown in FIG32, the deviation direction is opposite to that in the embodiment shown in FIG31, such that the deviation results in the distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the nearest node position NP105 being equal to tu, and the distance between the center position CP111 in the thickness direction of the oxide confinement layer 111 and the nearest node position NP111 being equal to t+u. Note that the embodiments shown in FIG31 and FIG32 can also be considered as a form of the platform M1 of Embodiment 1. That is, the embodiment shown in FIG31 corresponds to the case where t1=t+u and t2=tu. The embodiment shown in FIG32 corresponds to the case where t1=tu and t2=t+u. For example, when the design values ​​of t1 and t2 are represented by t, the embodiment shown in FIG6 can be regarded as an embodiment in which no film thickness deviation occurs, and the embodiments shown in FIG31 and FIG32 can both be regarded as embodiments in which film thickness deviation occurs.

[0211] Since the number of oxide confinement layers 105 and 111 is even, when the center position of each light-emitting layer in the thickness direction is aligned with the antinode position of the standing wave, each of the oxide confinement layers 105 and 111 can be a predetermined oxide confinement layer (an oxide confinement layer whose center position in the thickness direction is not aligned with the nearest node position of the standing wave).

[0212] As described above, the surface-emitting element 1000 enables the provision of high-power and high-efficiency VCSELs, which achieve high NA while suppressing crack formation and exhibit high robustness against film thickness variations.

[0213] <2. Surface light-emitting element according to Embodiment 2 of this technology>

[0214] Figure 16 is a cross-sectional view showing the mesa M2 extracted from the surface light-emitting element of Embodiment 2 according to the present technology.

[0215] As shown in FIG16, the surface light-emitting element according to Embodiment 2 has a similar configuration to the surface light-emitting element 1000 according to Embodiment 1, except that the direction in which each oxide confinement layer is displaced from the nearest node position is opposite to the direction of the surface light-emitting element 1000 according to Embodiment 1.

[0216] Similarly, in Embodiment 2, as an example, each of the oxide confinement layers 105 and 111 is a predetermined oxide confinement layer whose center position in the thickness direction does not coincide with any node position of the standing wave of the electric field of the emitted light (the standing wave generated in the resonator).

[0217] Specifically, in Embodiment 2, as an example, the center position CP105 in the thickness direction of the oxide confinement layer 105 is located on the second surface side (upper side) relative to the node position NP105 of the standing wave closest to the center position CP105, and the center position CP111 in the thickness direction of the oxide confinement layer 111 is located on the first surface side (lower side) relative to the node position NP111 of the standing wave closest to the center position CP111. That is, the positions of the oxide confinement layers 105 and 111 are located on opposite sides relative to their respective nearest node positions.

[0218] Here, as an example, in the oxide confinement layer 105 (predetermined oxide confinement layer), the position other than the center position CP105 in the thickness direction coincides with the node position NP105 closest to the center position CP105. Here, as an example, in the oxide confinement layer 111 (predetermined oxide confinement layer), the position other than the center position CP111 in the thickness direction coincides with the node position NP111 closest to the center position CP111.

[0219] t1 represents the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105 and the node position NP105 of the standing wave closest to the central position CP105, and L1 represents the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105 and the central position CP109 in the thickness direction of the second light-emitting layer 109, satisfying L1 = (2n - 1)λ / 4 - t1, where n is a natural number. Here, 0 < t1 ≤ λ / 4 (λ represents the oscillation wavelength).

[0220] t2 represents the distance between the central position CP111 in the thickness direction of the oxide confinement layer 111 and the node position NP111 of the standing wave closest to the central position CP111, and L2 represents the distance between the central position CP111 in the thickness direction of the oxide confinement layer 111 and the central position CP109 in the thickness direction of the second light-emitting layer 109, satisfying L2 = (2m - 1)λ / 4 - t2, where m is a natural number. Here, 0 < t2 ≤ λ / 4 (λ represents the oscillation wavelength).

[0221] In the embodiment shown in FIG. 16, t1 = t2 = t (0 < t ≤ λ / 4) and n = m = k (where k is a natural number and k = 2) are satisfied. This indicates that the oxide confinement layers 105 and 111 are arranged symmetrically with respect to the central position CP109 in the thickness direction of the second light-emitting layer 109.

[0222] That is, the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105 and the central position CP109 in the thickness direction of the second light-emitting layer 109 is equal to the distance between the central position CP111 in the thickness direction of the oxide confinement layer 111 and the central position CP109 in the thickness direction of the second light-emitting layer 109.

[0223] When L3 represents the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105 and the central position CP103 in the thickness direction of the first light-emitting layer 103, L3 = (2i - 1)λ / 4 + t3 (for 0 < t3 ≤ λ / 4) is satisfied, where i is a natural number. In the embodiment shown in FIG. 16, i = 2 and t3 = t.

[0224] The surface light-emitting element according to Embodiment 2 can exhibit an effect similar to that of the surface light-emitting element 1000 according to Embodiment 1.

[0225] <3. Surface light-emitting element of Embodiment 3 according to an embodiment of the present technology>

[0226] Figure 17 is a cross-sectional view of the surface light-emitting element 3000 according to Embodiment 3 of the present invention. Figure 18 is a cross-sectional view showing the mesa M3 extracted from the surface light-emitting element 3000 according to Embodiment 3 of the present invention.

[0227] As shown in Figure 17, the surface light-emitting element 3000 includes first to third light-emitting layers 103, 109 and 117.

[0228] Except that the third luminescent layer 117, the sixth cladding layer 118, the tunnel junction layer 119, and the seventh cladding layer 120 are sequentially stacked between the fourth cladding layer 108 and the second luminescent layer 109 from the side of the fourth cladding layer 108 (below), the surface-emitting element 3000 has a configuration similar to that of the surface-emitting element 1000 according to Embodiment 1. That is, in the surface-emitting element 3000, the tunnel junction layer 107 is disposed between the first luminescent layer 103 and the third luminescent layer 117, and the tunnel junction layer 119 is disposed between the second luminescent layer 109 and the third luminescent layer 117. In the surface-emitting element 3000, the luminescent layers and the tunnel junction layers are alternately stacked between the oxide confinement layers 105 and 111.

[0229] As an example, the third light-emitting layer 117 comprises a compound semiconductor with a bandgap energy lower than that of the fourth cladding layer 108 and the sixth cladding layer 118. For example, the third light-emitting layer 117 has alternating layers of undoped In. x17 Ga 1-x17 As (0 < x17 < 1) well layer and undoped Al x18 Ga 1-x18 As a stacked multi-quantum-well structure with (0 < x18 < 1) barrier layers. The third light-emitting layer 117 can be replaced by any of a quantum well structure, a quantum wiring structure, or a quantum dot structure. The emission wavelength of the third light-emitting layer 117 is set to be the same as the emission wavelength (e.g., 600 to 1100 nm) of the first light-emitting layer 103 and the second light-emitting layer 109. The third light-emitting layer 117 may be referred to as the "third active layer". Preferably, the center position of the third light-emitting layer 117 in the thickness direction coincides with the position of the antinode of the standing wave generated in the resonator.

[0230] For example, the sixth coating layer 118 includes p-Al x19 Ga 1-x19 As (0 ≤ x19 < 1). The "sixth coating layer" can be referred to as the "sixth spacer layer". Examples of p-type impurities (p-type dopants) used for the sixth coating layer 118 include Zn, Mg, Be, C, etc.

[0231] The tunnel junction layer 119 has the function of allowing current from the second light-emitting layer 109 to flow to the third light-emitting layer 117 through the tunneling effect while maintaining the current value. Preferably, a predetermined position (e.g., the center position) in the thickness direction of the tunnel junction layer 119 coincides with the node position of the standing wave. The tunnel junction layer 119 has a stacked structure, for example, including a highly doped p-type layer (p++ layer) and a highly doped n-type layer (n++ layer). The highly doped p-type layer includes, for example, GaAs or InGaAs containing p-type impurities (such as high-concentration carbon (C)), and the highly doped n-type layer includes, for example, GaAs or InGaAs containing n-type impurities (such as high-concentration tellurium (Te)). Here, the highly doped p-type layer is disposed on the substrate 100 side (lower side) of the highly doped n-type layer.

[0232] Here, the tunnel layer 107 has the function of allowing current from the third light-emitting layer 117 to flow to the first light-emitting layer 103 through the tunneling effect while maintaining the current value.

[0233] The seventh coating layer 120 includes, for example, n-Al x20 Ga 1-x20 As (0 ≤ x20 < 1). The "seventh cladding layer" can be referred to as the "seventh spacer layer". Examples of n-type impurities (n-type dopants) used for the seventh cladding layer 120 include Si, Se, Ge, etc.

[0234] Similarly, in Embodiment 3, as an example, each of the oxide confinement layers 105 and 111 is a predetermined oxide confinement layer whose center position in the thickness direction does not coincide with any node position of the standing wave of the electric field of the emitted light (the standing wave generated in the resonator), as shown in FIG18.

[0235] Specifically, as an embodiment, the center position CP105 in the thickness direction of the oxide confinement layer 105 is located on the first surface side (lower side) relative to the node position NP105 of the standing wave closest to the center position CP105. As an embodiment, the center position CP111 in the thickness direction of the oxide confinement layer 111 is located on the second surface side (upper side) relative to the node position NP111 of the standing wave closest to the center position CP111. That is, the positions of the oxide confinement layers 105 and 111 are located on opposite sides relative to their respective nearest node positions.

[0236] Here, as an example, in the oxide confinement layer 105 (predetermined oxide confinement layer), the position other than the center position CP105 in the thickness direction coincides with the node position NP105 closest to the center position CP105. Here, as an example, in the oxide confinement layer 111 (predetermined oxide confinement layer), the position other than the center position CP111 in the thickness direction coincides with the node position NP111 closest to the center position CP111.

[0237] t1 represents the distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the node position NP105 of the standing wave closest to the center position CP105, and L1 represents the distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the center position CP117 in the thickness direction of the third light-emitting layer 117, satisfying L1 = (2n-1)λ / 4 + t1, where n is a natural number. Here, 0 < t1 ≤ λ / 4 (λ represents the oscillation wavelength).

[0238] t2 represents the distance between the center position CP111 of the oxide confinement layer 111 in the thickness direction and the node position NP111 of the standing wave closest to the center position CP111. L2 represents the distance between the center position CP111 of the oxide confinement layer 111 in the thickness direction and the center position CP109 of the second light-emitting layer 109 in the thickness direction, satisfying L2 = (2m-1)λ / 4 + t2, where m is a natural number. Here, 0 < t2 ≤ λ / 4 (λ represents the oscillation wavelength).

[0239] In the embodiment shown in Figure 18, t1=t2=t (0<t≤λ / 4) and n=m=k (where k is a natural number and k=2).

[0240] That is, the distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the center position CP117 in the thickness direction of the third light-emitting layer 117 is equal to the distance between the center position CP111 in the thickness direction of the oxide confinement layer 111 and the center position CP109 in the thickness direction of the second light-emitting layer 109. The distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the center position CP117 in the thickness direction of the third light-emitting layer 117 is different from the distance between the center position CP111 in the thickness direction of the oxide confinement layer 111 and the center position CP117 in the thickness direction of the third light-emitting layer 117. The distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the center position CP109 in the thickness direction of the second light-emitting layer 109 is different from the distance between the center position CP111 in the thickness direction of the oxide confinement layer 111 and the center position CP109 in the thickness direction of the second light-emitting layer 109. Here, the oxide confinement layers 105 and 111 are arranged symmetrically with respect to the center position in the thickness direction of the tunnel layer 119, and the second light-emitting layer 109 and the third light-emitting layer 117 are arranged symmetrically.

[0241] When L3 represents the distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the center position CP103 in the thickness direction of the first light-emitting layer 103, L3 satisfies L3 = (2i-1)λ / 4 - t3 (0 < t3 ≤ λ / 4), where i is a natural number. In the embodiment shown in FIG18, i = 2 and t3 = t.

[0242] The surface light-emitting element 3000 according to Embodiment 3 can exhibit similar effects to the surface light-emitting element 1000 according to Embodiment 1, and, due to the provision of an additional light-emitting layer, a further increase in output power can be achieved.

[0243] <4. Surface-emitting element according to embodiment 4 of this technology>

[0244] Figure 19 is a cross-sectional view of the surface-emitting element 4000 according to Embodiment 4 of the present invention. Figure 20 is a cross-sectional view showing the mesa M4 extracted from the surface-emitting element 4000 according to Embodiment 4 of the present invention.

[0245] As shown in Figure 19, the surface light-emitting element 4000 includes first to third light-emitting layers 103, 109 and 117 and three oxide confinement layers 105, 111 and 121.

[0246] Except that the third light-emitting layer 117, the sixth cladding layer 118, the oxide confinement layer 121, the eighth cladding layer 122, the tunnel junction layer 119, and the seventh cladding layer 120 are sequentially stacked between the fourth cladding layer 108 and the second light-emitting layer 109 from the side of the fourth cladding layer 108 (below), the surface light-emitting element 4000 has a similar configuration to the surface light-emitting element 1000 according to Embodiment 1. That is, in the surface light-emitting element 3000, the tunnel junction layer 107 is disposed between the first light-emitting layer 103 and the third light-emitting layer 117, the tunnel junction layer 119 is disposed between the second light-emitting layer 109 and the third light-emitting layer 117, and the oxide confinement layer 121 is disposed between the second light-emitting layer 109 and the third light-emitting layer 117.

[0247] For example, the eighth coating layer 122 includes p-Al x21 Ga 1-x21 As (0 ≤ x21 < 1). The "eighth coating layer" can be referred to as the "eighth spacer layer". Examples of p-type impurities (p-type dopants) used for the eighth coating layer 122 include Zn, Mg, Be, C, etc.

[0248] As an example, the oxide confinement layer 121 includes a non-oxidized region 121a and an oxidized region 121b (insulating region) surrounding the non-oxidized region 121a.

[0249] The non-oxidized region 121a corresponds to the emission region of the second light-emitting layer 109 and the third light-emitting layer 117, and serves as a current and light transmission region. For example, the non-oxidized region 121a includes p-Al x22 Ga 1-x22 As (0 < x22 ≤ 1), and preferably x22 ≥ 0.8, and more preferably x22 ≥ 0.9. Examples of P-type impurities (P-type dopants) as non-oxidized regions 121a include Zn, Mg, Be, C, etc.

[0250] As an example, in a plan view, the oxidized region 121b is an annular (e.g., ring-shaped) region surrounding the non-oxidized region 121a. The oxidized region 121b has a higher resistivity and a lower refractive index than the non-oxidized region 121a, and serves as a current and optical confinement region. The oxidized region 121b comprises, for example, Al₂O₃ (alumina), and is formed, for example, by selectively oxidizing a pre-oxidized layer with a high Al composition (e.g., p-Al) from the side. x23 Ga 1-x23 As layers (0≤x23≤1) are formed.

[0251] As an example, the non-oxidized region 121a of the oxide confinement layer 121 is located at a position corresponding to the non-oxidized regions 105a and 111a of the oxide confinement layers 105 and 111. As an example, the oxide opening diameter (inner diameter of the oxidized region 121b) of the oxide confinement layer 121 is set to be the same as the oxide opening diameter (inner diameter of the oxidized regions 105b and 111b) of the oxide confinement layers 105 and 111.

[0252] The thickness of the oxide confinement layer 121 is preferably λ / 2 or less, more preferably λ / 4 or less, more preferably λ / 8 or less, and even more preferably λ / 16 or less. Here, λ represents the oscillation wavelength of the resonator.

[0253] In Embodiment 4, as shown in FIG20, oxide confinement layer 105 is a first oxide confinement layer located on the first surface side (lower side) relative to the third light-emitting layer 117, and oxide confinement layer 121 is a second oxide confinement layer located on the second surface side (upper side) relative to the third light-emitting layer 117. Oxide confinement layer 121 is a first oxide confinement layer located on the first surface side (lower side) relative to the second light-emitting layer 109, and oxide confinement layer 111 is a second oxide confinement layer located on the second surface side (upper side) relative to the second light-emitting layer 109.

[0254] In Embodiment 4, one of the first and second oxide confinement layers corresponding to (near) the third light-emitting layer 117 (oxide confinement layer 105 as the first oxide confinement layer) and one of the first and second oxide confinement layers corresponding to (near) the second light-emitting layer 109 (oxide confinement layer 111 as the second oxide confinement layer) are predetermined oxide confinement layers whose center position in the thickness direction does not coincide with any node position of the standing wave (the standing wave generated in the resonator) of the electric field of the emitted light. The center position CP121 of the oxide confinement layer 121 in the thickness direction coincides with the node position of the standing wave.

[0255] The center position CP105 of the oxide confinement layer 105 (which is the first oxide confinement layer corresponding to the third light-emitting layer 117) in the thickness direction is located on the first surface side (lower side) relative to the node position NP105 of the standing wave closest to the center position CP105, and the center position CP121 of the oxide confinement layer 121 (which is the second oxide confinement layer corresponding to the third light-emitting layer 117) in the thickness direction coincides with the node position of the standing wave.

[0256] The central position CP111 in the thickness direction of the oxide confinement layer 111 (which is the second oxide confinement layer corresponding to the second light-emitting layer 109) is located on the second surface side (upper side) with respect to the node position NP111 of the standing wave closest to the central position CP111, and the central position CP121 in the thickness direction of the oxide confinement layer 121 (which is the first oxide confinement layer corresponding to the second light-emitting layer 109) coincides with the node position of the standing wave.

[0257] L1 represents the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105, which is the first oxide confinement layer corresponding to the third light-emitting layer 117, and the central position CP117 in the thickness direction of the third light-emitting layer 117. L2 represents the distance between the central positions CP121 in the thickness direction of the oxide confinement layer 121, which is the second oxide confinement layer corresponding to the third light-emitting layer 117, and the central position CP117 in the thickness direction of the third light-emitting layer 117. And t1 represents the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105 and the node position NP105 of the standing wave closest to the central position CP105, satisfying L1 = (2n - 1)λ / 4 + t1 and L2 = (2m - 1)λ / 4, where n and m are natural numbers. Here, 0 < t1 ≤ λ / 4 (λ represents the oscillation wavelength).

[0258] In the embodiment shown in FIG. 20, t1 = t (0 < t ≤ λ / 4) is satisfied, and n = m = k (where k is a natural number and k = 2).

[0259] The central position CP121 in the thickness direction of the oxide confinement layer 121, which is the first oxide confinement layer corresponding to the second light-emitting layer 109, coincides with the node position of the standing wave, and the central position CP111 in the thickness direction of the oxide confinement layer 111, which is the second oxide confinement layer corresponding to the second light-emitting layer 109, is located on the second surface side (upper side) with respect to the node position NP111 of the standing wave closest to the central position CP111.

[0260] L1 represents the distance between the central positions CP111 in the thickness direction of the oxide confinement layer 111, which is the second oxide confinement layer corresponding to the second light-emitting layer 109, and the central position CP109 in the thickness direction of the second light-emitting layer 109. L2 represents the distance between the central positions CP121 in the thickness direction of the oxide confinement layer 121, which is the first oxide confinement layer corresponding to the second light-emitting layer 109 and the central position CP109 in the thickness direction of the second light-emitting layer 109. And t2 represents the distance between the central position CP111 in the thickness direction of the oxide confinement layer 111 and the node position NP111 closest to the central position CP111, satisfying L1 = (2n - 1)λ / 4 + t2 and L2 = (2m - 1)λ / 4, where n and m are natural numbers. Here, 0 < t2 ≤ λ / 4 (λ represents the oscillation wavelength).

[0261] In the embodiment shown in FIG. 20, t2 = t (0 < t ≤ λ / 4) is satisfied, and n = m = k (where k is a natural number and k = 2).

[0262] When L3 represents the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105 and the central position CP103 in the thickness direction of the first light-emitting layer 103, L3 = (2i - 1)λ / 4 - t3 (0 < t3 ≤ λ / 4) is satisfied, where i is a natural number. In the embodiment shown in FIG. 20, i = 2 and t3 = t.

[0263] The surface light-emitting element 4000 according to Embodiment 4 can exhibit an effect similar to that of the surface light-emitting element 1000 according to Embodiment 1, and furthermore, due to the provision of additional light-emitting layers and oxide confinement layers, an increase in output power and efficiency can be achieved.

[0264] <5. The surface light-emitting element according to Embodiment 5 of the embodiment of the present technology>

[0265] FIG. 21 is a cross-sectional view of a surface light-emitting element 5000 according to Embodiment 5 of the embodiment of the present technology.

[0266] As shown in FIG. 21, the surface light-emitting element 5000 has a configuration substantially similar to that of the surface light-emitting element 1000 according to Embodiment 1, except that it is a back-emission type and has a mesa with opposite conductive types (p-type and n-type).

[0267] In the surface light-emitting element 5000, a contact layer 113 (for example, p-Al x16 Ga 1-x16 As (0 ≤ x16 < 1)) is provided between the substrate 100 and the second semiconductor multilayer reflector 112.

[0268] Here, as an embodiment, the second semiconductor multilayer reflector 112, oxide confinement layer 111, fifth cladding layer 110, second light-emitting layer 109, fourth cladding layer 108, tunnel junction layer 107, third cladding layer 106, oxide confinement layer 105, second cladding layer 104, first light-emitting layer 103, first cladding layer 102, first semiconductor multilayer reflector 101, and contact layer 123 are stacked in this order from the substrate 100 side (bottom side) to form a mesa M5. The contact layer 123 is a layer highly doped with p-type impurities and includes, for example, p-Al. X24 Ga 1-X24 As (0 ≤ X24 < 1).

[0269] A planar cathode electrode 114 is disposed in a contact hole 116b, which is disposed in an insulating film 116 on the top of the platform M5 (specifically, on the contact layer 123) to make ohmic contact with the contact layer 123.

[0270] An annular (e.g., ring-shaped) anode electrode 115 is disposed in an annular (e.g., ring-shaped) contact hole 116c, which is disposed in an insulating film 116 on a region of the contact layer 113 surrounding the mesa M5, so as to make ohmic contact with the contact layer 113. That is, the surface-emitting element 5000 has an in-cavity structure and can reduce the series resistance. In the surface-emitting element 5000, for example, a semi-insulating GaAs substrate can also be used as the substrate 100.

[0271] The surface-emitting element 5000 according to Embodiment 5 can exhibit similar effects to the surface-emitting element 1000 according to Embodiment 1, and enables the provision of a back-emitting VCSEL exhibiting low power consumption, high output power and high efficiency.

[0272] <6. Surface-emitting element according to Embodiment 6 of the present technology>

[0273] Figure 22 is a cross-sectional view of the surface light-emitting element 6000 according to Embodiment 6 of the present invention. Figure 23 is a cross-sectional view showing the mesa M6 extracted from the surface light-emitting element 6000 according to Embodiment 6 of the present invention.

[0274] As shown in Figures 22 and 23, the surface light-emitting element 6000 has a configuration substantially similar to that of the surface light-emitting element 1000 according to Embodiment 1, except that it does not provide the third covering layer 106, the tunneling layer 107, the fourth covering layer 108, the second light-emitting layer 109, and the fifth covering layer 110.

[0275] That is, the surface light-emitting element 6000 is a VCSEL with a single light-emitting layer (first light-emitting layer 103).

[0276] In the surface light-emitting element 6000, an oxide confinement layer 105 is disposed between a first semiconductor multilayer reflector 101 and a first cladding layer 102, and an oxide confinement layer 111 is disposed between a second cladding layer 104 and a second semiconductor multilayer reflector 112.

[0277] In the surface light-emitting element 6000, the oxide confinement layer 105, the first cladding layer 102, the first light-emitting layer 103, the second cladding layer 104, the oxide confinement layer 111, the second semiconductor multilayer reflector 112, and the contact layer 113 are stacked in this order from the substrate 100 side (bottom side) to form a mesa M6.

[0278] Similarly, in Embodiment 6, as an example, each of the oxide confinement layers 105 and 111 is a predetermined oxide confinement layer whose center position in the thickness direction is not consistent with any node position of the standing wave of the electric field of the emitted light (the standing wave generated in the resonator), as shown in FIG23.

[0279] Specifically, as an embodiment, the center position CP105 in the thickness direction of the oxide confinement layer 105 is located on the second surface side (upper side) relative to the node position NP105 of the standing wave closest to the center position CP105, and the center position CP111 in the thickness direction of the oxide confinement layer 111 is located on the first surface side (lower side) relative to the node position NP111 of the standing wave closest to the center position CP111. That is, the positions of the oxide confinement layers 105 and 111 are located on opposite sides relative to their respective nearest node positions.

[0280] Here, as an embodiment, in the oxide confinement layer 105 (a predetermined oxide confinement layer), the position in the thickness direction other than the center position CP105 (e.g., the lowest position) coincides with the node position NP105 closest to the center position CP105. Here, as an embodiment, in the oxide confinement layer 111 (a predetermined oxide confinement layer), the position in the thickness direction other than the center position CP111 (e.g., the uppermost position) coincides with the node position NP111 closest to the center position CP111.

[0281] t1 represents the distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the node position NP105 of the standing wave closest to the center position CP105, and L1 represents the distance between the center position CP105 in the thickness direction of the oxide confinement layer 105 and the center position CP103 in the thickness direction of the first light-emitting layer 103, satisfying L1 = (2n-1)λ / 4 - t1, where n is a natural number. Here, 0 < t1 ≤ λ / 4 (λ represents the oscillation wavelength).

[0282] t2 represents the distance between the central position CP111 in the thickness direction of the oxide confinement layer 111 and the node position NP111 of the standing wave closest to the central position CP111, and L2 represents the distance between the central position CP111 in the thickness direction of the oxide confinement layer 111 and the central position CP103 in the thickness direction of the first light-emitting layer 103, satisfying L2 = (2m - 1)λ / 4 - t2, where m is a natural number. Here, 0 < t2 ≤ λ / 4 (λ represents the oscillation wavelength).

[0283] In the embodiment shown in Fig. 23, t1 = t2 = t (0 < t ≤ λ / 4) and n = m = k (where k is a natural number and k = 2) are satisfied. This indicates that the oxide confinement layers 105 and 111 are symmetrically arranged with respect to the central position CP103 in the thickness direction of the first light-emitting layer 103.

[0284] That is, the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105 and the central position CP103 in the thickness direction of the first light-emitting layer 103 is equal to the distance between the central position CP111 in the thickness direction of the oxide confinement layer 111 and the central position CP103 in the thickness direction of the first light-emitting layer 103.

[0285] The surface-emitting element 6000 according to Embodiment 6 can exhibit an effect similar to that of the surface-emitting element 1000 according to Embodiment 1, and it becomes possible to provide a high-efficiency VCSEL with a simple configuration. Note that in Embodiment 6, only one of the oxide confinement layers 105 and 111 can be a predetermined oxide confinement layer.

[0286] <7. The surface-emitting element of Embodiment 7 according to an embodiment of the present technology>

[0287] Fig. 24 is a cross-sectional view showing the mesa M7 extracted from the surface-emitting element of Embodiment 7 according to an embodiment of the present technology.

[0288] As shown in Fig. 24, the surface-emitting element according to Embodiment 7 has a configuration similar to that of the surface-emitting element 6000 according to Embodiment 6, except that the central position CP105 in the thickness direction of the oxide confinement layer 105 is located on the first surface side (lower side) with respect to the node position NP105 of the standing wave closest to (nearest to) the central position CP105, and the central position CP111 in the thickness direction of the oxide confinement layer 111 is located on the first surface side (upper side) of the node position NP111 of the standing wave closest to (nearest to) the central position CP111. <00In Embodiment 7, t1 represents the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105 and the node position NP105 of the standing wave closest to the central position CP105, and L1 represents the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105 and the central position CP103 in the thickness direction of the first light-emitting layer 103, satisfying L1 = (2n - 1)λ / 4 + t1, where n is a natural number. Here, 0 < t1 ≤ λ / 4 (λ represents the oscillation wavelength).

[0290] In Embodiment 7, t2 represents the distance between the central position CP111 in the thickness direction of the oxide confinement layer 111 and the node position NP111 of the standing wave closest to the central position CP111, and L2 represents the distance between the central position CP111 in the thickness direction of the oxide confinement layer 111 and the central position CP103 in the thickness direction of the first light-emitting layer 103, satisfying L2 = (2m - 1)λ / 4 + t2, where m is a natural number. Here, 0 < t2 ≤ λ / 4 (λ represents the oscillation wavelength).

[0291] In the embodiment shown in FIG. 24, t1 = t2 = t (0 < t ≤ λ / 4) and n = m = k (where k is a natural number and k = 2) are satisfied. This indicates that the oxide confinement layers 105 and 111 are symmetrically arranged with respect to the central position CP103 in the thickness direction of the first light-emitting layer 103.

[0292] The surface light-emitting element according to Embodiment 7 can exhibit an effect similar to that of the surface light-emitting element 6000 according to Embodiment 6.

[0293] <8. Surface light-emitting element of Embodiment 8 according to an embodiment of the present technology>

[0294] FIG. 25 is a cross-sectional view showing the mesa M8 extracted from the surface light-emitting element of Embodiment 8 according to an embodiment of the present technology.

[0295] As shown in FIG. 25, except that t1 ≠ t2, for example, t1 > t2, the surface light-emitting element according to Embodiment 8 has a configuration similar to that of the surface light-emitting element 6000 according to Embodiment 6. Note that t1 < t2 can be satisfied.

[0296] The surface light-emitting element according to Embodiment 8 can exhibit an effect similar to that of the surface light-emitting element 6000 according to Embodiment 6.

[0297] <9. Surface light-emitting element of Embodiment 9 according to an embodiment of the present technology>

[0298] FIG. 26 is a cross-sectional view showing the mesa M9 extracted from the surface light-emitting element of Embodiment 9 according to an embodiment of the present technology.

[0299] As shown in Figure 26, the surface-emitting element according to Embodiment 9 has a similar configuration to the surface-emitting element according to Embodiment 7, except that t1 ≠ t2, for example, t2 > t1. Note that t2 < t1 can be satisfied.

[0300] The surface-emitting element according to Example 9 can exhibit similar effects to the surface-emitting element 6000 according to Example 6.

[0301] <10. Surface-emitting element according to Embodiment 10 of the present technology>

[0302] Figure 27 is a cross-sectional view showing the mesa M10 extracted from the surface light-emitting element of Embodiment 10 according to the present technology.

[0303] As shown in Figure 27, except that n=m=k=1 in L1 and L2, the surface light-emitting element according to Embodiment 10 has a similar configuration to the surface light-emitting element according to Embodiment 7.

[0304] The surface-emitting element according to Example 10 can exhibit similar effects to the surface-emitting element 6000 according to Example 6.

[0305] <11. Surface-emitting element according to embodiment 11 of the present technology>

[0306] Figure 28 is a cross-sectional view showing the mesa M11 extracted from the surface light-emitting element of Embodiment 11 according to the present technology.

[0307] As shown in Figure 28, except that n=m=k=1 in L1 and L2, the surface light-emitting element according to Embodiment 11 has a configuration that is substantially the same as that of the surface light-emitting element according to Embodiment 6.

[0308] The surface-emitting element according to Embodiment 11 does not include the first covering layer 102 and the second covering layer 104, but may include them.

[0309] The surface-emitting element according to Embodiment 11 can exhibit similar effects to the surface-emitting element 6000 according to Embodiment 6.

[0310] <12. Surface-emitting element according to Embodiment 12 of the present technology>

[0311] Figure 29 is a cross-sectional view showing the mesa M12 extracted from the surface light-emitting element of Embodiment 12 according to the present technology.

[0312] As shown in Figure 29, the surface-emitting element according to Embodiment 12 has a structure in which an emitting layer and an oxide confinement layer are additionally provided to the surface-emitting element 4000 according to Embodiment 4. Specifically, the surface-emitting element 4000 has a configuration substantially similar to that of the surface-emitting element 4000 according to Embodiment 4, except that the tunnel junction layer 124, the ninth cladding layer 125, the fourth emitting layer 126, the tenth cladding layer 127, the oxide confinement layer 128, and the eleventh cladding layer 129 are sequentially stacked in the mesa M12 between the eighth cladding layer 122 and the tunnel junction layer 119 from the side (below) of the eighth cladding layer 122.

[0313] The tunnel junction layer 124 has the function of allowing current from the fourth light-emitting layer 126 to flow to the third light-emitting layer 117 through the tunneling effect while maintaining the current value. Preferably, the predetermined position in the thickness direction of the tunnel junction layer 124 coincides with the node position of the standing wave. The tunnel junction layer 124 has, for example, a stacked structure including a highly doped p-type layer (p++ layer) and a highly doped n-type layer (n++ layer). The highly doped p-type layer includes, for example, GaAs or InGaAs containing p-type impurities (such as high-concentration carbon (C)), and the highly doped n-type layer includes, for example, GaAs or InGaAs containing n-type impurities (such as high-concentration tellurium (Te)). Here, the highly doped p-type layer is disposed on the first surface side (lower side) of the highly doped n-type layer.

[0314] The ninth coating layer 125 includes, for example, n-Al x25 Ga 1-x25 As (0 ≤ x25 < 1). The "ninth cladding layer" can be referred to as the "ninth spacer layer". Examples of n-type impurities (n-type dopants) used for the ninth cladding layer 125 include Si, Se, Ge, etc.

[0315] As an example, the fourth light-emitting layer 126 comprises a compound semiconductor having a bandgap energy lower than that of the ninth cladding layer 125 and the tenth cladding layer 127. The fourth light-emitting layer 126 has, for example, a multiple quantum well structure comprising alternating layers of undoped In. x26 Ga 1-26 As (0 < x26 < 1) well layer and undoped Al x27 Ga 1-x27 As a stack of barrier layers (0 < x27 < 1). The fourth light-emitting layer 126 can have any of the following structures instead of a multi-quantum-well structure: a quantum well structure, a quantum wiring structure, or a quantum dot structure. The emission wavelength of the fourth light-emitting layer 126 is set to be the same as the emission wavelength (e.g., 600 to 1100 nm) of the first to third light-emitting layers 103, 109, and 117. The fourth light-emitting layer 126 can be referred to as the "fourth active layer". Preferably, the center position CP126 of the fourth light-emitting layer 126 in the thickness direction coincides with the position of the antinode of the standing wave generated in the resonator.

[0316] The tenth coating layer 127 includes, for example, p-Al x28 Ga 1-x28 As (0 ≤ x28 < 1). The "tenth coating layer" can be referred to as the "tenth spacer layer". Examples of p-type impurities (p-type dopants) in the tenth coating layer 127 include Zn, Mg, Be, C, etc.

[0317] As an example, the oxide confinement layer 128 includes a non-oxidized region and an oxidized region (insulating region) surrounding the non-oxidized region.

[0318] The non-oxidized region corresponds to the emission regions of the second emitting layer 109 and the fourth emitting layer 126, and serves as the current and light transmission region. For example, the non-oxidized region includes p-Al. x29 Ga 1-x29 As (0 < x29 ≤ 1), and preferably x29 ≥ 0.8, and more preferably x29 ≥ 0.9. Examples of P-type impurities (P-type dopants) as non-oxidized regions include Zn, Mg, Be, C, etc.

[0319] As an example, the oxidized region in a planar view is a ring-shaped region surrounding the non-oxidized region. The oxidized region has a higher resistivity and a lower refractive index than the non-oxidized region and serves as a current and optical confinement region. The oxidized region includes, for example, Al₂O₃ (alumina), and is achieved, for example, by selectively oxidizing a pre-oxidized layer with a high Al composition (e.g., p-Al) from the side. x30 Ga 1-x30 As layers (0≤x30≤1) are formed.

[0320] As an example, the non-oxidized regions of the oxide confinement layer 128 are located at positions corresponding to the non-oxidized regions 105a, 111a, and 121a of the oxide confinement layers 105, 111, and 121. As an example, the oxide opening diameter (inner diameter of the oxidized region) of the oxide confinement layer 128 is set to be the same as the oxide opening diameter (inner diameter of the oxidized regions 105b, 111b, and 121b) of the oxide confinement layers 105, 111, and 121.

[0321] The thickness of the oxide confinement layer 128 is preferably λ / 2 or less, more preferably λ / 4 or less, more preferably λ / 8 or less, and even more preferably λ / 16 or less. Here, λ represents the oscillation wavelength of the resonator.

[0322] In Embodiment 12, oxide confinement layer 105 is a first oxide confinement layer located on the first surface side (lower side) relative to the third light-emitting layer 117, and oxide confinement layer 121 is a second oxide confinement layer located on the second surface side (upper side) relative to the third light-emitting layer 117. Oxide confinement layer 121 is a first oxide confinement layer located on the first surface side (lower side) relative to the fourth light-emitting layer 126, and oxide confinement layer 128 is a second oxide confinement layer located on the second surface side (upper side) relative to the fourth light-emitting layer 126. Oxide confinement layer 128 is a first oxide confinement layer located on the first surface side (lower side) relative to the second light-emitting layer 109, and oxide confinement layer 111 is a second oxide confinement layer located on the second surface side (upper side) relative to the second light-emitting layer 109.

[0323] In embodiment 12, the first and second oxide confinement layers (oxide confinement layers 105 and 121) correspond to (close to) the third light-emitting layer 117, the first and second oxide confinement layers (oxide confinement layers 121 and 128) correspond to (close to) the fourth light-emitting layer 126, and the first and second oxide confinement layers (oxide confinement layers 128 and 111) corresponding to (close to) the second light-emitting layer 109 are predetermined oxide confinement layers whose center position in the thickness direction does not coincide with any node position of the standing wave of the electric field of the emitted light (the standing wave generated in the resonator).

[0324] The center position CP105 of the oxide confinement layer 105, which is the first oxide confinement layer corresponding to the third light-emitting layer 117, is located on the first surface side (lower side) of the node position NP105 of the standing wave closest to the center position CP105. The center position CP121 of the oxide confinement layer 121, which is the second oxide confinement layer corresponding to the third light-emitting layer 117, is located on the second surface side (upper side) of the node position NP121 of the standing wave closest to the center position CP121.

[0325] L1 represents the distance between the center position CP105 of the oxide confinement layer 105 (which is the first oxide confinement layer corresponding to the third light-emitting layer 117) in the thickness direction and the center position CP117 of the third light-emitting layer 117 in the thickness direction, and t1 represents the distance between the center position CP105 of the oxide confinement layer 105 in the thickness direction and the node position NP105 of the standing wave closest to the center position CP105, satisfying L1 = (2n-1)λ / 4 + t1, where n is a natural number. Here, 0 < t1 ≤ λ / 4 (λ represents the oscillation wavelength).

[0326] L2 represents the distance between the central position CP121 in the thickness direction of the oxide confinement layer 121 (which is the second oxide confinement layer corresponding to the third light-emitting layer 117) and the central position CP117 in the thickness direction of the third light-emitting layer 117, and t2 represents the distance between the central position CP121 in the thickness direction of the oxide confinement layer 121 and the node position NP121 of the standing wave closest to the central position CP121, satisfying L2 = (2m - 1)λ / 4 + t2, where m is a natural number. Here, 0 < t2 ≤ λ / 4 (λ represents the oscillation wavelength).

[0327] Here, t1 = t2 = t (0 < t ≤ λ / 4) and n = m = k (where k is a natural number and k = 2) are satisfied. That is, L1 = L2 is satisfied.

[0328] The central position CP121 in the thickness direction of the oxide confinement layer 121, which is the first oxide confinement layer corresponding to the fourth light-emitting layer 126, is located on the second surface side (upper side) with respect to the node position NP121 of the standing wave closest to the central position CP121, and the central position CP128 in the thickness direction of the oxide confinement layer 128, which is the second oxide confinement layer corresponding to the fourth light-emitting layer 126, is located on the first surface side (lower side) of the node position NP128 of the standing wave closest to the central position CP128.

[0329] L1 represents the distance between the central position CP121 in the thickness direction of the oxide confinement layer 121, which is the first oxide confinement layer corresponding to the fourth light-emitting layer 126, and the central position CP126 in the thickness direction of the fourth light-emitting layer 126, and t1 represents the distance between the central position CP121 in the thickness direction of the oxide confinement layer 121 and the node position NP121 of the standing wave closest to the central position CP121, satisfying L1 = (2n - 1)λ / 4 - t1, where n is a natural number. Here, 0 < t1 ≤ λ / 4 (λ represents the oscillation wavelength).

[0330] L2 represents the distance between the central position CP128 in the thickness direction of the oxide confinement layer 128 (which is the second oxide confinement layer corresponding to the fourth light-emitting layer 126) and the central position CP126 in the thickness direction of the fourth light-emitting layer 126, and t2 represents the distance between the central position CP128 in the thickness direction of the oxide confinement layer 128 and the node position NP128 of the standing wave closest to the central position CP128, satisfying L2 = (2m - 1)λ / 4 - t2, where m is a natural number. Here, 0 < t2 ≤ λ / 4 (λ represents the oscillation wavelength).

[0331] Here, t1 = t2 = t (0 < t ≤ λ / 4) and n = m = k (where k is a natural number and k = 2) are satisfied. That is, L1 = L2 is satisfied.

[0332] The central position CP128 in the thickness direction of the oxide confinement layer 128, which is the first oxide confinement layer corresponding to the second light-emitting layer 109, is located on the first surface side (lower side) with respect to the node position NP128 of the standing wave closest to the central position CP128, and the central position CP111 in the thickness direction of the oxide confinement layer 111, where the oxide confinement layer 111 is the second oxide confinement layer corresponding to the second light-emitting layer 109, is located on the second surface side (upper side) of the node position NP111 of the standing wave closest to the central position CP111.

[0333] When L1 represents the distance between the central position CP128 in the thickness direction of the oxide confinement layer 128 (which is the first oxide confinement layer corresponding to the second light-emitting layer 109) and the central position CP109 in the thickness direction of the second light-emitting layer 109, and t1 represents the distance between the central position CP128 in the thickness direction of the oxide confinement layer 128 and the node position NP128 of the standing wave closest to the central position CP128, L1 = (2n - 1)λ / 4 + t1 is satisfied, where n is a natural number. Here, 0 < t1 ≤ λ / 4 (λ represents the oscillation wavelength).

[0334] When L2 represents the distance between the central position CP111 in the thickness direction of the oxide confinement layer 111 (which is the second oxide confinement layer corresponding to the second light-emitting layer 109) and the central position CP109 in the thickness direction of the second light-emitting layer 109, and t2 represents the distance between the central position CP111 in the thickness direction of the oxide confinement layer 111 and the node position NP111 of the standing wave closest to the central position CP111, L2 = (2m - 1)λ / 4 + t2 is satisfied, where m is a natural number. Here, 0 < t2 ≤ λ / 4 (λ represents the oscillation wavelength).

[0335] Here, t1 = t2 = t (0 < t ≤ λ / 4) and n = m = k (where k is a natural number and k = 2) are satisfied. That is, L1 = L2 is satisfied.

[0336] When L3 represents the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105 and the central position CP103 in the thickness direction of the first light-emitting layer 103, L3 = (2i - 1)λ / 4 - t3 (0 < t3 ≤ λ / 4) is satisfied, where i is a natural number. In the embodiment shown in FIG. 29, i = 2 and t3 = t.

[0337] The surface-emitting element according to Embodiment 12 can exhibit similar effects to the surface-emitting element 4000 according to Embodiment 4, and further increases in output power and efficiency can be achieved due to the provision of an additional light-emitting layer and oxide confinement layer.

[0338] <13. Surface-emitting element according to embodiment 13 of the present technology>

[0339] Figure 30 is a cross-sectional view showing the mesa M13 extracted from the surface light-emitting element of Embodiment 13 according to the present technology.

[0340] As shown in Figure 30, the surface-emitting element according to Embodiment 13 has a structure in which an emitting layer and an oxide confinement layer are additionally provided to the surface-emitting element according to Embodiment 12. Specifically, the surface-emitting element according to Embodiment 13 has a configuration that is substantially the same as that of the surface-emitting element according to Embodiment 12, except that the tunnel junction layer 130, the twelfth cladding layer 131, the fifth emitting layer 132, the thirteenth cladding layer 133, the oxide confinement layer 134, and the fourteenth cladding layer 135 are stacked sequentially from the eleventh cladding layer 129 side (bottom side) between the eleventh cladding layer 129 and the tunnel junction layer 119 in the mesa M13.

[0341] The tunnel junction 130 has the function of allowing current from the fifth light-emitting layer 132 to flow to the fourth light-emitting layer 126 through the tunneling effect while maintaining the current value. The tunnel junction 130 has, for example, a stacked structure including a highly doped p-type layer (p++ layer) and a highly doped n-type layer (n++ layer). The highly doped p-type layer includes, for example, GaAs or InGaAs containing p-type impurities (such as high-concentration carbon (C)), and the highly doped n-type layer includes, for example, GaAs or InGaAs containing n-type impurities (such as high-concentration tellurium (Te)). Here, the highly doped p-type layer is disposed on the first surface side (lower side) of the highly doped n-type layer.

[0342] The twelfth cladding layer 131 includes, for example, n-Al. x31 Ga 1-x31 As (0 ≤ x31 < 1). The "twelfth cladding layer" can be referred to as the "twelfth spacer layer". Examples of n-type impurities (n-type dopants) used for the twelfth cladding layer 131 include Si, Se, Ge, etc.

[0343] As an example, the fifth light-emitting layer 132 comprises a compound semiconductor having a bandgap energy smaller than that of the twelfth cladding layer 131 and the thirteenth cladding layer 133. The fifth light-emitting layer 132, for example, comprises alternating layers of undoped In. x32 Ga 1- 32 As (0 < x32 < 1) well layer and undoped Alx33 Ga 1-x33 As a stacked multi-quantum-well structure of blocking layers (0 < x33 < 1). The fifth light-emitting layer 132 may have any one of a quantum well structure, a quantum wiring structure, or a quantum dot structure instead of a multi-quantum-well structure. The emission wavelength of the fifth light-emitting layer 132 is set to be the same as the emission wavelength (e.g., 600 to 1100 nm) of the first to fourth light-emitting layers 103, 109, 117, and 126. The fifth light-emitting layer 132 may be referred to as the "fifth active layer". Preferably, the center position CP132 of the fifth light-emitting layer 132 in the thickness direction coincides with the position of the antinode of the standing wave generated in the resonator.

[0344] The thirteenth cladding layer 133 includes, for example, p-Al. x34 Ga 1-x34 As (0 ≤ x34 < 1). The "thirteenth cladding layer" can be referred to as the "thirteenth spacer layer". Examples of p-type impurities (p-type dopants) in the thirteenth cladding layer 133 include Zn, Mg, Be, C, etc.

[0345] As an example, the oxide confinement layer 134 includes a non-oxidized region and an oxidized region (insulating region) surrounding the non-oxidized region.

[0346] The non-oxidized region corresponds to the emission region of the second emitting layer 109 and the fifth emitting layer 132, and serves as the current and light transmission region. For example, the non-oxidized region includes p-Al. x35 Ga 1-x35 As (0 < x35 ≤ 1), and preferably x35 ≥ 0.8, and more preferably x35 ≥ 0.9. Examples of P-type impurities (P-type dopants) as non-oxidized regions include Zn, Mg, Be, C, etc.

[0347] As an example, the oxidized region in a planar view is a ring-shaped region surrounding the non-oxidized region. The oxidized region has a higher resistivity and a lower refractive index than the non-oxidized region and serves as a current and optical confinement region. The oxidized region includes, for example, Al₂O₃ (alumina), and is achieved, for example, by selectively oxidizing a pre-oxidized layer with a high Al composition (e.g., p-Al) from the side. x36 Ga 1-x36 As layers (0≤x36≤1) are formed.

[0348] As an example, the non-oxidized region of the oxide confinement layer 134 is located at a position corresponding to the non-oxidized regions of oxide confinement layers 105, 111, 121, and 128. As an example, the oxide opening diameter (inner diameter of the oxidized region) of the oxide confinement layer 134 is set to be the same as the oxide opening diameter (inner diameter of the oxidized region) of oxide confinement layers 105, 111, 121, and 128.

[0349] The thickness of the oxide confinement layer 134 is preferably λ / 2 or less, more preferably λ / 4 or less, more preferably λ / 8 or less, and even more preferably λ / 16 or less. Here, λ represents the oscillation wavelength of the resonator.

[0350] In Embodiment 13, oxide confinement layer 105 is a first oxide confinement layer located on the first surface side (lower side) relative to the third light-emitting layer 117, and oxide confinement layer 121 is a second oxide confinement layer located on the second surface side (upper side) relative to the third light-emitting layer 117. Oxide confinement layer 121 is a first oxide confinement layer located on the first surface side (lower side) relative to the fourth light-emitting layer 126, and oxide confinement layer 128 is a second oxide confinement layer located on the second surface side (upper side) relative to the fourth light-emitting layer 126. Oxide confinement layer 128 is a first oxide confinement layer located on the first surface side (lower side) relative to the fifth light-emitting layer 132, and oxide confinement layer 134 is a second oxide confinement layer located on the second surface side (upper side) relative to the fifth light-emitting layer 132. Oxide confinement layer 134 is a first oxide confinement layer located on the first surface side (lower side) of the second light-emitting layer 109, and oxide confinement layer 111 is a second oxide confinement layer located on the second surface side (upper side) of the second light-emitting layer 109.

[0351] In Embodiment 13, the first and second oxide confinement layers (oxide confinement layers 105 and 121) correspond to (approach) the third light-emitting layer 117, the first oxide confinement layer (oxide confinement layer 121) corresponds to (approach) the fourth light-emitting layer 126, the second oxide confinement layer (oxide confinement layer 134) corresponds to (approach) the fifth light-emitting layer 132, and the first and second oxide confinement layers (oxide confinement layers 134 and 111) corresponding to (approach) the second light-emitting layer 109 are predetermined oxide confinement layers whose center position in the thickness direction does not coincide with any node position of the standing wave (the standing wave generated in the resonator) of the electric field of the emitted light. The oxide confinement layer 128, which is the second oxide confinement layer corresponding to (approach) the fourth light-emitting layer 126 and the first oxide confinement layer corresponding to (approach) the fifth light-emitting layer 132, has its center position in the thickness direction coincided with the node position of the standing wave.

[0352] The central position CP105 in the thickness direction of the oxide confinement layer 105, which is the first oxide confinement layer corresponding to the third light-emitting layer 117, is located on the first surface side (lower side) with respect to the node position NP105 of the standing wave closest to the central position CP105. And for the central position CP121 in the thickness direction of the oxide confinement layer 121, which is the second oxide confinement layer corresponding to the third light-emitting layer 117, it is located on the second surface side (upper side) of the node position NP121 of the standing wave closest to the central position CP121.

[0353] L1 represents the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105, which is the first oxide confinement layer corresponding to the third light-emitting layer 117, and the central position CP117 in the thickness direction of the third light-emitting layer 117. And t1 represents the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105 and the node position NP105 of the standing wave closest to the central position CP105, satisfying L1 = (2n - 1)λ / 4 + t1, where n is a natural number. Here, 0 < t1 ≤ λ / 4 (λ represents the oscillation wavelength).

[0354] L2 represents the distance between the central position CP121 in the thickness direction of the oxide confinement layer 121 (which is the second oxide confinement layer corresponding to the third light-emitting layer 117) and the central position CP117 in the thickness direction of the third light-emitting layer 117. And t2 represents the distance between the central position CP121 in the thickness direction of the oxide confinement layer 121 and the node position NP121 of the standing wave closest to the central position CP121, satisfying L2 = (2m - 1)λ / 4 + t2, where m is a natural number. Here, 0 < t2 ≤ λ / 4 (λ represents the oscillation wavelength).

[0355] Here, t1 = t2 = t (0 < t ≤ λ / 4) and n = m = k are satisfied, where k is a natural number and k = 2. That is, L1 = L2 is satisfied.

[0356] The central position CP121 in the thickness direction of the oxide confinement layer 121 (which is the first oxide confinement layer corresponding to the fourth light-emitting layer 126) is located on the second surface side (upper side) with respect to the node position NP121 of the standing wave closest to the central position CP121, and the central position CP128 in the thickness direction of the oxide confinement layer 128 (which is the second oxide confinement layer corresponding to the fourth light-emitting layer 126) coincides with the node position of the standing wave.

[0357] L1 represents the distance between the central position CP121 in the thickness direction of the oxide confinement layer 121, which is the first oxide confinement layer corresponding to the fourth light-emitting layer 126, and the central position CP126 in the thickness direction of the fourth light-emitting layer 126, and t1 represents the distance between the central position CP121 in the thickness direction of the oxide confinement layer 121 and the node position NP121 of the standing wave closest to the central position CP121, satisfying L1 = (2n - 1)λ / 4 - t1, where n is a natural number. Here, 0 < t1 ≤ λ / 4 (λ represents the oscillation wavelength).

[0358] L2 represents the distance between the central position CP128 in the thickness direction of the oxide confinement layer 128, which is the second oxide confinement layer corresponding to the fourth light-emitting layer 126, and the central position CP126 in the thickness direction of the fourth light-emitting layer 126, satisfying L2 = (2m - 1)λ / 4, where m is a natural number.

[0359] Here, t1 = t (0 < t ≤ λ / 4) and n = m = k (where k is a natural number and k = 2) are satisfied. That is, L1 ≠ L2 is satisfied.

[0360] The central position CP128 in the thickness direction of the oxide confinement layer 128, which is the first oxide confinement layer corresponding to the fifth light-emitting layer 132, coincides with the node position of the standing wave, and the central position CP134 in the thickness direction of the oxide confinement layer 134, which is the second oxide confinement layer corresponding to the fifth light-emitting layer 132, is located on the first surface side (lower side) with respect to the node position NP134 of the standing wave closest to the central position CP134.

[0361] When L1 represents the distance between the central position CP128 in the thickness direction of the oxide confinement layer 128, which is the first oxide confinement layer corresponding to the fifth light-emitting layer 132, and the central position CP132 in the thickness direction of the fifth light-emitting layer 132, it satisfies L1 = (2n - 1)λ / 4, where n is a natural number.

[0362] L2 represents the distance between the central position CP134 in the thickness direction of the oxide confinement layer 134, which is the second oxide confinement layer corresponding to the fifth light-emitting layer 132, and the central position CP132 in the thickness direction of the fifth light-emitting layer 132, and t2 represents the distance between the central position CP134 in the thickness direction of the oxide confinement layer 134 and the node position NP134 of the standing wave closest to the central position CP134, satisfying L2 = (2m - 1)λ / 4 - t2, where m is a natural number. Here, 0 < t2 ≤ λ / 4 (λ represents the oscillation wavelength).

[0363] Here, t2 = t (0 < t ≤ λ / 4) and n = m = k (where k is a natural number and k = 2) are satisfied. That is, L1 ≠ L2 is satisfied.

[0364] The central position CP134 in the thickness direction of the oxide confinement layer 134, which is the first oxide confinement layer corresponding to the second light-emitting layer 109, is located on the first surface side (lower side) with respect to the node position NP134 of the standing wave closest to the central position CP134, and the central position CP111 in the thickness direction of the oxide confinement layer 111. The oxide confinement layer 111 is the second oxide confinement layer corresponding to the second light-emitting layer 109 and is located on the second surface side (upper side) of the node position NP111 of the standing wave closest to the central position CP111.

[0365] L1 represents the distance between the central position CP134 in the thickness direction of the oxide confinement layer 134, which is the first oxide confinement layer corresponding to the second light-emitting layer 109, and the central position CP109 in the thickness direction of the second light-emitting layer 109, and t1 represents the distance between the central position CP134 in the thickness direction of the oxide confinement layer 134 and the node position NP134 of the standing wave closest to the central position CP134. L1 = (2n - 1)λ / 4 + t1 is satisfied, where n is a natural number. Here, 0 < t1 ≤ λ / 4 (λ represents the oscillation wavelength).

[0366] L2 represents the distance between the central position CP111 in the thickness direction of the oxide confinement layer 111 (which is the second oxide confinement layer corresponding to the second light-emitting layer 109) and the central position CP109 in the thickness direction of the second light-emitting layer 109, and t2 represents the distance between the central position CP111 in the thickness direction of the oxide confinement layer 111 and the node position NP111 of the standing wave closest to the central position CP111. L2 = (2m - 1)λ / 4 + t2 is satisfied, where m is a natural number. Here, 0 < t2 ≤ λ / 4 (λ represents the oscillation wavelength).

[0367] Here, t1 = t2 = t (0 < t ≤ λ / 4) and n = m = k (where k is a natural number and k = 2) are satisfied. That is, L1 = L2 is satisfied.

[0368] When L3 represents the distance between the central position CP105 in the thickness direction of the oxide confinement layer 105 and the central position CP103 in the thickness direction of the first light-emitting layer 103, L3 = (2i - 1)λ / 4 - t3 (0 < t3 ≤ λ / 4) is satisfied, where i is a natural number. Here, i = 2 and t3 = t.

[0369] The surface light-emitting element according to Embodiment 13 can exhibit an effect similar to that of the surface light-emitting element according to Embodiment 12, and due to the provision of an additional light-emitting layer and an oxide confinement layer, a further increase in output power and efficiency can be achieved.

[0370] <14. Modifications of the Present Technology>

[0371] The present technology is not limited to the above embodiments and can be appropriately modified.

[0372] As an example, in the surface light-emitting element of Modification 1 of Embodiment 7 of the embodiment shown in FIG. 33, in L1 and L2 of mesa MM1, n≠m (for example, n>m) and t1=t2=t can be satisfied. It should be noted that in L1 and L2 of mesa MM1, n<m and t1 = t2 = t can be satisfied.

[0373] As an example, in the surface light-emitting element of Modification 2 of Embodiment 7 of the embodiment shown in FIG. 34, in L1 and L2 of mesa MM2, n≠m (for example, n>m) and t1≠t2 (for example, t1>t2) can be satisfied. It should be noted that in L1 and L2 of mesa MM2, n<m and t1 ≠ t2 (t1>t2 or t1<t2) can be satisfied.

[0374] For example, even when the number of oxide confinement layers is even, as the number of light-emitting layers increases to 3, 4, 5,..., and correspondingly the number of oxide confinement layers increases to 3, 4, 5,..., the positional relationship between the oxide confinement layer and the light-emitting layer in its vicinity can be set as in Embodiments 1, 2, 3, 5, and 6 to 12, and when the number of oxide confinement layers is odd, the positional relationship can be set as in Embodiments 4 and 13. Further, for example, in the case where there are four oxide confinement layers, the displacement of the central position in the thickness direction of the oxide confinement layer from the node position of the standing wave (“-” indicates downward displacement and “+” indicates upward displacement) can be set to -t, -t, +t, +t; +t, +t, -t, -t; -t, +t, -t, +t; or +t, -t, +t, -t from bottom to top. That is, as long as approximately half of the oxide confinement layers are displaced from the node position in the + direction (upward) and the remaining approximately half are displaced from the node position in the - direction (downward), the combination is arbitrary. This also applies to the case where the number of oxide confinement layers is odd or the conductive type (p-type and n-type) is reversed. Further, even when the offset of the central position in the thickness direction of the oxide confinement layer from the node position of the standing wave is not equal, as long as approximately half of the central positions are offset from the node position in the + direction and the remaining approximately half are offset from the node position in the - direction, a certain degree of effect can be obtained.

[0375] When the number of multiple oxide confinement layers is even, each of the multiple oxide confinement layers can be the predetermined oxide confinement layer described above.

[0376] When the number of multiple oxide confinement layers is an odd number of three or more, each oxide confinement layer obtained by excluding at least one oxide confinement layer from the odd number of three or more oxide confinement layers can be the predetermined oxide confinement layer described above.

[0377] For example, a light-emitting diode (LED) can be configured by replacing at least one of the first semiconductor multilayer reflector 101 or the second semiconductor multilayer reflector 112 with a covering layer (e.g., an AlGaAs layer) in the surface light-emitting element according to each of the above embodiments and variations.

[0378] For example, a surface light-emitting element array can be constructed by arranging the surface light-emitting elements according to each of the above embodiments and variations in a one-dimensional or two-dimensional manner.

[0379] In each of the above embodiments and variations of the surface light-emitting element, a buffer layer may be provided between the substrate 100 and the first semiconductor multilayer reflector 101.

[0380] In each of the surface-emitting elements according to the above embodiments and variations, a contact layer is not required.

[0381] In each of the above embodiments and variations, GaAs-based (GaAs lattice-matched material system) surface-emitting elements are primarily described. However, the technology is not limited to this and can also be applied to, for example, InP-based (InP lattice-matched material system) and GaN-based (GaN lattice-matched material system) surface-emitting elements. Embodiments of InP-based material systems include AlGaInP-based material systems, AlGaInAs-based material systems, and AlInAs-based material systems.

[0382] That is, materials whose emission wavelength falls within the wavelength range of 200 nm to 2000 nm can be used in surface-emitting elements according to this technology. Any suitable compound semiconductor can be used as a material for surface-emitting elements according to this technology.

[0383] In each of the above embodiments and variations, arsenic (As)-based semiconductors have been described as embodiments, but III-V semiconductors containing, for example, nitrogen (N), boron (B), antimony (Sb), or phosphorus (P) can be used as needed.

[0384] At least one of the first structure ST1 and the second structure ST2 may include a reflector, which is not limited to a semiconductor multilayer reflector, but may instead be made of one or more materials selected from semiconductors, dielectrics, and metals.

[0385] In the surface-emitting element according to each of the above embodiments and variations, the conductivity types (p-type and n-type) of the first structure ST1 and the second structure ST2 can be reversed.

[0386] As long as they are not inconsistent with each other, some components of the surface-emitting elements according to each of the above embodiments and variations can be combined.

[0387] In the above embodiments and modifications, as long as the operation of the surface-emitting element is ensured, the arrangement, material, conductivity type, thickness, width, value, shape, and size of the layers constituting the surface-emitting element can be appropriately modified. Furthermore, regardless of how the material, composition, film thickness, constituent elements, shape, name, driving mechanism, manufacturing method, or application of the surface-emitting element is changed, similar effects can be obtained as long as the surface-emitting element has the features according to the claims of this disclosure.

[0388] <15. Configuration Examples of Surface Emitting Lasers to which this Technology Can Be Applied>

[0389] Figure 35 is a plan view showing a surface-emitting laser 20000, which is a configuration embodiment of a surface-emitting laser to which this technology can be applied. Figure 36A is a cross-sectional view taken along line XX in Figure 35. Figure 36B is a cross-sectional view taken along line YY in Figure 35.

[0390] Each component of the surface-emitting laser 20000 is stacked on a substrate 2001. The substrate 2001 may include semiconductors such as GaAs, InGaAs, InP, or InAsP.

[0391] The surface-emitting laser 20000 includes a protective region 2002 (the transparent gray area in Figures 36A and 36B). As shown in Figure 35, the protective region 2002 is circular in shape in the plan view, but it can also be elliptical, polygonal, or other shapes, and is not limited to a specific shape. The protective region 2002 includes a material that provides electrical isolation and is, for example, an ion-implanted region.

[0392] Furthermore, as shown in Figures 36A and 36B, the surface-emitting laser 20000 includes a first electrode 2003 and a second electrode 2004. As shown in Figure 35, the first electrode 2003 has an annular shape with a discontinuous (discontinuous) cross-section in a planar view, i.e., an open annular shape, but is not limited to any particular shape. As shown in Figure 36A or 36B, the second electrode 2004 is in contact with the substrate 2001. The first electrode 2003 and the second electrode 2004 comprise conductive materials such as Ti, Pt, Au, AuGeNi, or PdGeAu. The first electrode 2003 and the second electrode 2004 can have a single-layer structure or a multi-layer structure.

[0393] Furthermore, the surface-emitting laser 20000 includes trenches 2005 disposed around the protective region 2002. For example, Figure 35 shows a structure in which six trenches 2005 with a rectangular shape in a plan view are provided, but the number and shape of the trenches in the plan view are not limited to any particular form. The trenches 2005 are openings for forming an oxide confinement layer 2006 (containing oxidized regions 2006a and non-oxidized regions 2006b). During the manufacturing process of the surface-emitting laser 20000, high-temperature steam is supplied via the trenches 2005 to form the oxidized regions 2006a of the oxide confinement layer 2006. For example, the oxidized regions 2006a are Al2O3 formed due to the oxidation of an AlAs or AlGaAs layer. After the process of forming the oxide confinement layer 2006, any dielectric can be embedded in the trenches 2005. Alternatively, a surface coating can be formed using a dielectric film.

[0394] Furthermore, the surface-emitting laser 20000 includes a dielectric opening 2008 (contact hole) disposed through a dielectric layer 2007 on the first electrode 2003. The dielectric layer 2007 may have a multilayer structure as shown in Figures 36A and 36B, or it may have a single-layer structure. The dielectric layer 2007 includes, for example, silicon oxide, silicon nitride, etc. As shown in Figure 35, the dielectric opening 2008 is formed with the same shape as the first electrode 2003. However, the shape of the dielectric opening 2008 is not limited to the shape of the first electrode 2003, and the dielectric opening 2008 may be partially formed on the first electrode 2003. The dielectric opening 2008 is filled with a conductive material (not shown), and the conductive material is in contact with the first electrode 2003.

[0395] Furthermore, as shown in Figures 36A and 36B, the surface-emitting laser 20000 includes an optical aperture 2009 inside the first electrode 2003. The surface-emitting laser 20000 emits a beam through the optical aperture 2009. Additionally, in the surface-emitting laser 20000, the oxidized region 2006a of the oxide confinement layer 2006 serves as a current and optical confinement region for confining current and light. The non-oxidized region 2006b of the oxide confinement layer 2006 is located below the optical aperture 2009 and serves as a current and light transmission region for transmitting current and light.

[0396] Furthermore, the surface-emitting laser 20000 includes a first multilayer reflector 2011 and a second multilayer reflector 2012. Such a multilayer reflector is, for example, a semiconductor multilayer reflector and is also referred to as a distributed Bragg reflector.

[0397] Furthermore, the surface-emitting laser 20000 includes an active layer 2013. The active layer 2013 is disposed between the first multilayer reflector 2011 and the second multilayer reflector 2012, which restricts the injected carriers and determines the emission wavelength of the surface-emitting laser 20000.

[0398] In this configuration embodiment, as an example, the case where the surface-emitting laser 20000 is a front-emitting type has been described, but the surface-emitting laser 20000 can also be a back-emitting type.

[0399] As shown in Figures 35 and 36A, the effective diameter of the surface-emitting laser 20000 in this configuration embodiment is the diameter d of the virtual circle defined by the groove 2005.

[0400] As an example, the surface-emitting laser 20000 of this configuration embodiment is manufactured through the following processes 1 to 8.

[0401] (Process 1) Epitaxially grow a first multilayer reflector 2011, an active layer 2013, a selectively oxidized layer that becomes an oxide confinement layer 2006, and a second multilayer reflector 2012 on the surface of a substrate 2001.

[0402] (Process 2) The first electrode 2003 is formed on the second multilayer reflector 2012 by, for example, a stripping method.

[0403] (Process 3) The trench 2005 is formed, for example, by photolithography.

[0404] (Process 4) Expose the side surface of the layer to be selectively oxidized, and form an oxide confinement layer 2006 by selectively oxidizing the layer to be selectively oxidized from the side surface.

[0405] (Process 5) A protective region 2002 is formed by ion implantation or the like.

[0406] (Process 6) Dielectric layer 2007 is formed by, for example, vapor deposition, sputtering, etc.

[0407] (Process 7) A dielectric opening 2008 is formed, for example, by photolithography through the dielectric layer 2007 to expose the contacts of the first electrode 2003.

[0408] (Process 8) After the substrate 2001 is thinned by back grinding, a second electrode 2004 is formed on the back side of the substrate 2001.

[0409] The number, arrangement, thickness, order, and symmetry of the layers constituting the surface-emitting laser 20000 described above are merely embodiments and can be appropriately modified. That is, the surface-emitting laser 20000 may include more or fewer layers than those shown in Figures 35, 36A, and 36B, or may include layers that are different from those shown in Figures 35, 36A, and 36B, layers with different structures, or layers with different arrangements.

[0410] This technology can be applied to the aforementioned surface-emitting laser 20000 and its variations.

[0411] <16. Examples of Applications of Electronic Devices>

[0412] The technology disclosed herein (the Technology) can be applied to a variety of products (electronic devices). For example, the Technology disclosed herein can be implemented as a device installed on any type of mobile body (such as a car, electric vehicle, hybrid electric vehicle, motorcycle, bicycle, personal mobility device, aircraft, drone, ship, or robot); a low-power device (e.g., a smartphone, smartwatch, tablet computer, mouse, etc.); or a communication device for optical communication via waveguides such as optical fibers.

[0413] The surface-emitting element according to this technology can also be used as a light source, for example, in devices that form or display images by means of light (e.g., printers, copiers, projectors, head-mounted displays, head-up displays, etc.).

[0414] <17. Examples of applying surface-emitting elements in distance measuring devices>

[0415] In the following, an application example of the surface light-emitting element 1000 according to Embodiment 1 of the present technology will be described.

[0416] Figure 37 shows a schematic configuration embodiment of a distance measuring device 10000 (rangefinder) including a surface-emitting element 1000 as an embodiment of an electronic device according to the present technology. The distance measuring device 10000 measures the distance to an object S using a time-of-flight (TOF) method. The distance measuring device 10000 includes the surface-emitting element 1000. The distance measuring device 10000 includes, for example, the surface-emitting element 1000, a light receiving device 140, lenses 145 and 153, a signal processing unit 155, a control unit 160, a display unit 165, and a storage unit 175.

[0417] The light receiving device 140 receives light emitted from the surface light-emitting element 1000 and reflected by the object S (the object). That is, the light receiving device 140 detects the light reflected by the object S. Lens 145 is a lens used to calibrate the light emitted from the surface light-emitting element 1000, and is, for example, a calibration lens. Lens 153 is a lens used to collect the light reflected by the object S and guide that light to the light receiving device 140, and is, for example, a condenser lens.

[0418] The signal processing unit 155 is a circuit for generating a signal corresponding to the difference between the signal input from the light receiving device 140 and the reference signal input from the control unit 160. The control unit 160 includes, for example, a time-to-digital converter (TDC). The reference signal may be a signal input from the control unit 160, or it may be the output signal of a detection unit that directly detects the output of the surface-emitting element 1000. For example, the control unit 160 is a processor that controls the surface-emitting element 1000, the light receiving device 140, the signal processing unit 155, the display unit 165, and the storage unit 175. The control unit 160 is a circuit that measures the distance to the object S based on the signal generated by the signal processing unit 155. The control unit 160 generates an image signal for displaying information related to the distance to the object S and outputs the image signal to the display unit 165. The display unit 165 displays information about the distance to the object S based on the video signal input from the control unit 160. The control unit 160 stores the information about the distance to the object S in the storage unit 175.

[0419] In this application embodiment, instead of the surface light-emitting element 1000, any of the surface light-emitting elements according to Embodiments 2 to 13 and the variations can be applied to the distance measuring device 10000.

[0420] <18. Example of mounting a distance measuring device on a moving body>

[0421] Figure 38 is a block diagram illustrating a schematic configuration embodiment of a vehicle control system as an example of a mobile body control system capable of applying the technology according to this disclosure.

[0422] The vehicle control system 12000 includes multiple electronic control units interconnected via a communication network 12001. In the embodiment shown in FIG38, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. Furthermore, a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network interface (I / F) 12053 are shown as functional components of the integrated control unit 12050.

[0423] The drive system control unit 12010 controls the operation of devices related to the vehicle's drive system according to various programs. For example, the drive system control unit 12010 is used as a control device for drive force generating devices (such as internal combustion engines or drive motors) that generate drive force for the vehicle, drive force transmission mechanisms that transmit drive force to the wheels, steering mechanisms that adjust the vehicle's steering angle, and braking devices that generate braking force for the vehicle.

[0424] The body system control unit 12020 controls the operation of various devices installed on the vehicle body according to various programs. For example, the body system control unit 12020 is used as a control device for keyless entry systems, smart key systems, power windows, or various lights such as headlights, taillights, brake lights, turn signals, and fog lights. In this case, radio waves or signals from various switches transmitted from a portable device that serves as a substitute key can be input to the body system control unit 12020. The body system control unit 12020 receives these radio wave or signal inputs and controls the vehicle's door locking devices, power windows, lights, etc.

[0425] The external information detection unit 12030 detects external information about the vehicle equipped with the vehicle control system 12000. For example, a distance measuring device 12031 is connected to the external information detection unit 12030. The distance measuring device 12031 includes the aforementioned distance measuring device 10000. The external information detection unit 12030 uses the distance measuring device 12031 to determine the distance to an object (object S) outside the vehicle and obtains this distance data. In addition, the external information detection unit 12030 can also perform detection processing of people, vehicles, obstacles, signs, etc., based on the obtained distance data.

[0426] The in-vehicle information detection unit 12040 detects information about the interior of the vehicle. The in-vehicle information detection unit 12040 is connected, for example, to a driver state detection unit 12041 that detects the driver's state. The driver state detection unit 12041 includes, for example, a camera that captures images of the driver. Based on the detection information input from the driver state detection unit 12041, the in-vehicle information detection unit 12040 can calculate the driver's fatigue level or concentration level, or determine whether the driver is dozing off.

[0427] The microcomputer 12051 can calculate target control values ​​for the drive force generation device, steering mechanism, or braking device based on information about the vehicle's interior or exterior obtained by the external information detection unit 12030 or the internal information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control designed to implement functions of advanced driver assistance systems (ADAS), including vehicle collision avoidance or damping, distance-based following, speed-keeping driving, collision warning, lane departure warning, etc.

[0428] In addition, the microcomputer 12051 controls the drive force generating device, steering mechanism, braking device, etc. based on the information about the vehicle's surroundings obtained by the external information detection unit 12030 or the internal information detection unit 12040. As a result, it can perform coordinated control for autonomous driving without relying on the driver's operation.

[0429] Additionally, the microcomputer 12051 can output control commands to the body system control unit 12020 based on the external information obtained by the external information detection unit 12030. For example, the microcomputer 12051 can control the headlights based on the position of the vehicle in front or oncoming vehicle detected by the external information detection unit 12030 to perform cooperative control aimed at preventing glare, such as switching from high beam to low beam.

[0430] The audio / image output unit 12052 sends an output signal of at least one of audio or image to an output device capable of providing information visually or audibly to the occupants of the vehicle or to the exterior of the vehicle. In the embodiment of FIG38, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are shown as embodiments of the output device. For example, the display unit 12062 may include at least one of an on-board display or a head-up display.

[0431] Figure 39 is a diagram showing an example of the installation position of the distance measuring mechanism 12031.

[0432] In Figure 39, vehicle 12100 includes distance measuring devices 12101, 12102, 12103, 12104 and 12105 as distance measuring device 12031.

[0433] For example, distance measuring devices 12101, 12102, 12103, 12104, and 12105 are installed inside the vehicle 12100 at locations such as the front nose, side mirrors, rear bumper, rear door, and the upper part of the windshield. Distance measuring device 12101 installed at the front nose and distance measuring device 12105 installed at the upper part of the windshield primarily acquire data from the front of the vehicle 12100. Distance measuring devices 12102 and 12103 installed at the side mirrors primarily acquire data from the sides of the vehicle 12100. Distance measuring device 12104 installed at the rear bumper or rear door primarily acquires data from the rear of the vehicle 12100. The data acquired from the front by distance measuring devices 12101 and 12105 is mainly used to detect vehicles, pedestrians, obstacles, traffic lights, traffic signs, etc., ahead.

[0434] Note that Figure 39 illustrates an embodiment of the detection range of distance measuring devices 12101 to 12104. Detection range 12111 indicates the detection range of distance measuring device 12101 located at the front bumper, detection ranges 12112 and 12113 indicate the detection ranges of distance measuring devices 12102 and 12103 located at the side mirrors, respectively, and detection range 12114 indicates the detection range of distance measuring device 12104 located at the rear bumper or rear door.

[0435] For example, the microcomputer 12051 obtains the distance to each three-dimensional object within the detection range 12111 to 12114 and the time change of that distance (relative speed relative to the vehicle 12100) based on distance data obtained from distance measuring devices 12101 to 12104. Thus, it can specifically identify vehicles on the driving path of the vehicle 12100 that are traveling in approximately the same direction as the vehicle 12100 and at a predetermined speed (e.g., equal to or greater than 0 km / h) as preceding vehicles. Furthermore, the microcomputer 12051 can preset a following distance to be maintained relative to the preceding vehicle and execute automatic braking control (including follow-stop control), automatic acceleration control (including follow-start control), etc. Therefore, coordinated control for automated driving is possible without relying on driver operation.

[0436] For example, microcomputer 12051 can extract three-dimensional object data about three-dimensional objects based on distance data obtained from distance measuring devices 12101 to 12104 and classify them into two-wheeled vehicles, standard-sized vehicles, large vehicles, pedestrians, and other three-dimensional objects (such as utility poles), and use this three-dimensional object data for automatic obstacle avoidance. For example, microcomputer 12051 identifies obstacles around vehicle 12100 as obstacles that the driver of vehicle 12100 can visually recognize and obstacles that the driver of vehicle 12100 cannot visually recognize. Then, microcomputer 12051 determines a collision risk indicating the risk of collision with each obstacle. If the collision risk is equal to or higher than a set value and therefore there is a possibility of collision, microcomputer 12051 can output a warning to the driver via audio speaker 12061 or display unit 12062 or perform forced deceleration or evasive steering via drive system control unit 12010, thereby providing driver assistance for collision avoidance.

[0437] The embodiments of a mobile body control system to which the technology according to the present disclosure can be applied have been described above. The technology according to the present disclosure can be applied to the distance measuring device 12031 in the above configuration.

[0438] In addition, this technology may also have the following configurations.

[0439] (1) A surface-emitting element, comprising: a first structure including a first semiconductor structure; a second structure including a second semiconductor structure, the second structure being stacked on the first structure; at least one light-emitting layer disposed between the first structure and the second structure; and a plurality of oxide confinement layers disposed between a first surface and a second surface, the first surface being a surface of the first structure away from the second structure, the second surface being a surface of the second structure away from the first structure, the plurality of oxide confinement layers being stacked together with the light-emitting layer and stacked together with each other, wherein the plurality of oxide confinement layers includes at least one predetermined oxide confinement layer, the center position of the at least one predetermined oxide confinement layer in the thickness direction being inconsistent with any node position of the standing wave of the electric field of the emitted light.

[0440] (2) The surface light-emitting element according to (1), wherein the position other than the center position of the predetermined oxide confinement layer is consistent with the node position.

[0441] (3) The surface light-emitting element according to (1), wherein the predetermined oxide confinement layer is offset from the node position closest to the center position throughout the thickness direction.

[0442] (4) The surface light-emitting element according to any one of (1) to (3), wherein the plurality of oxide confinement layers includes at least two predetermined oxide confinement layers.

[0443] (5) The surface light-emitting element according to any one of (1) to (4), wherein the plurality of oxide confinement layers include oxide confinement layers and the center position of the oxide confinement layers coincides with the node position.

[0444] (6) The surface light-emitting element according to any one of (1) to (5), wherein t represents the distance between the center position and the node position closest to the center position, and the distance between the center position and the center position in the thickness direction of the light-emitting layer is expressed as (2k-1)λ / 4+t or (2k-1)λ / 4-t, where k is a natural number.

[0445] (7) A surface light-emitting element according to any one of (1) to (6), wherein the plurality of oxide confinement layers comprises: at least one first oxide confinement layer disposed on a first surface side relative to the light-emitting layer; and at least one second oxide confinement layer disposed on a second surface side relative to the light-emitting layer, and the first oxide confinement layer and / or the second oxide confinement layer are predetermined oxide confinement layers.

[0446] (8) The surface light-emitting element according to (7), wherein there are at least two predetermined oxide confinement layers, and

[0447] The first oxide confinement layer and the second oxide confinement layer are predetermined oxide confinement layers, respectively.

[0448] (9) The surface-emitting element according to (7) or (8), wherein the center position of the first oxide confinement layer in the thickness direction is located on one of the first surface side and the second surface side of the node position closest to the center position; and

[0449] The center of the second oxide confinement layer in the thickness direction is located on the other side of the first and second surface sides of the node position closest to the center position.

[0450] (10) A surface light-emitting element according to any one of (7) to (9), wherein L1 represents the distance between the center position in the thickness direction of the first oxide confinement layer and the center position in the thickness direction of the light-emitting layer, L2 represents the distance between the center position in the thickness direction of the second oxide confinement layer and the center position in the thickness direction of the light-emitting layer, t1 represents the distance between the center position in the thickness direction of the first oxide confinement layer and the node position closest to the center position, and t2 represents the distance between the center position in the thickness direction of the second oxide confinement layer and the node position closest to the center position, and satisfies L1=(2n-1)λ / 4+t1 and L2=(2m-1)λ / 4+t2 or L1=(2n-1)λ / 4-t1 and L2=(2m-1)λ / 4-t2 where n and m are natural numbers.

[0451] (11) The surface light-emitting element according to (10), wherein t1 = t2.

[0452] (12) The surface light-emitting element according to any one of (7) to (11), wherein the distance between the center position of the first oxide confinement layer in the thickness direction and the center position of the light-emitting layer in the thickness direction is equal to the distance between the center position of the second oxide confinement layer in the thickness direction and the center position of the light-emitting layer in the thickness direction.

[0453] (13) The surface light-emitting element according to any one of (7) to (12), wherein one of the first oxide confinement layer and the second oxide confinement layer is a predetermined oxide confinement layer.

[0454] (14) The surface light-emitting element according to any one of (7) to (13), wherein the center position in the thickness direction of one of the first oxide confinement layer and the second oxide confinement layer is located on the first surface side or the second surface side of the node position closest to the center position, and the center position in the thickness direction of the other of the first oxide confinement layer and the second oxide confinement layer coincides with the node position.

[0455] (15) A surface light-emitting element according to any one of (7) to (14), wherein L1 represents the distance between the center position in the thickness direction of one of the first oxide confinement layer and the center position in the thickness direction of the light-emitting layer, L2 represents the distance between the center position in the thickness direction of the other of the first oxide confinement layer and the center position in the thickness direction of the light-emitting layer, and t represents the distance between the center position in the thickness direction of one of the first oxide confinement layer and the node position closest to the center position, and satisfies L1=(2n-1)λ / 4+t and L2=(2m-1)λ / 4 or L1=(2n-1)λ / 4-t and L2=(2m-1)λ / 4, where n and m are natural numbers.

[0456] (16) The surface light-emitting element according to any one of (7) to (15), wherein the distance between the center position of the first oxide confinement layer in the thickness direction and the center position of the light-emitting layer in the thickness direction is different from the distance between the center position of the second oxide confinement layer in the thickness direction and the center position of the light-emitting layer in the thickness direction.

[0457] (17) A surface-emitting element according to any one of (1) to (16), wherein each of the plurality of oxide confinement layers comprises: a non-oxidized region; and an oxide region surrounding the non-oxidized region, wherein the non-oxidized region comprises Al x Ga1-x As (0.8≤x≤1).

[0458] (18) A surface light-emitting element according to any one of (1) to (17), wherein at least one light-emitting layer comprises a plurality of light-emitting layers stacked on top of each other, and the surface light-emitting element further comprises a tunnel junction layer disposed between at least two adjacent light-emitting layers forming a pair among the plurality of light-emitting layers.

[0459] (19) The surface light-emitting element according to (18), wherein a predetermined oxide confinement layer is disposed between one of two adjacent light-emitting layers and the tunnel junction layer.

[0460] (20) The surface light-emitting element according to (18) or (19), wherein the predetermined position in the thickness direction of the tunnel layer coincides with the node position.

[0461] (21) A surface light-emitting element according to any one of (1) to (20), wherein the number of the plurality of oxide confinement layers is even, and each of the plurality of oxide confinement layers corresponds to a predetermined oxide confinement layer.

[0462] (22) A surface-emitting element according to any one of (1) to (21), wherein the number of the plurality of oxide confinement layers is an odd number of three or more, and

[0463] Each oxide confinement layer obtained by excluding at least one oxide confinement layer from an odd number of three or more oxide confinement layers corresponds to a predetermined oxide confinement layer.

[0464] Reference Symbol List

[0465] Surface-emitting diodes (SLEDs) with speeds of 1000, 2000, 3000, 4000, 5000, and 6000 ohms

[0466] 100 substrates

[0467] 101 First semiconductor multilayer reflector (first semiconductor structure)

[0468] 103 First luminescent layer (luminescent layer)

[0469] 109 Second luminescent layer (luminescent layer)

[0470] 117 Third luminescent layer (luminescent layer)

[0471] 126 Fourth luminescent layer (luminescent layer)

[0472] 132 Fifth luminescent layer (luminescent layer)

[0473] Oxide confinement layers 105, 111, 121, 128, 134

[0474] Tunnel layers 107, 119, 124, 130

[0475] 112 Second semiconductor multilayer reflector (part of a second semiconductor structure)

[0476] 113 Contact layer (part of the second semiconductor structure)

[0477] ST1 First Structure

[0478] ST2 Second Structure

[0479] SS1 First Semiconductor Structure

[0480] SS2 Second Semiconductor Structure

Claims

1. A surface-emitting element, comprising: The first structure includes a first semiconductor structure; The second structure includes a second semiconductor structure, which is stacked on the first structure; At least one light-emitting layer is disposed between the first structure and the second structure; And a plurality of oxide confinement layers are disposed between a first surface and a second surface, the first surface being the surface of the first structure away from the second structure, and the second surface being the surface of the second structure away from the first structure. The plurality of oxide confinement layers are stacked together with the light-emitting layer and stacked together with each other. The plurality of oxide confinement layers include at least one predetermined oxide confinement layer, the center position of which in the thickness direction is not consistent with any node position of the standing wave of the electric field of the emitted light.

2. The surface-emitting element according to claim 1, wherein, The positions other than the center position of the predetermined oxide confinement layer are consistent with the node positions.

3. The surface-emitting element according to claim 1, wherein, The predetermined oxide confinement layer is offset from the node position closest to the center position throughout the entire thickness direction.

4. The surface-emitting element according to claim 1, wherein, The plurality of oxide confinement layers include at least two predetermined oxide confinement layers.

5. The surface-emitting element according to claim 1, wherein, The plurality of oxide confinement layers include oxide confinement layers, the center position of which coincides with the node position.

6. The surface-emitting element according to claim 1, wherein, t represents the distance between the center position and the node position closest to the center position. The distance between the center position and the center position in the thickness direction of the light-emitting layer is expressed as (2k-1)λ / 4 + t or (2k-1)λ / 4–t, where k is a natural number.

7. The surface-emitting element according to claim 1, wherein, The plurality of oxide confinement layers include: at least one first oxide confinement layer disposed on the first surface side relative to the light-emitting layer; and at least one second oxide confinement layer disposed on the second surface side relative to the light-emitting layer, wherein the first oxide confinement layer and / or the second oxide confinement layer is the predetermined oxide confinement layer.

8. The surface-emitting element according to claim 7, wherein, There are at least two predetermined oxide confinement layers, and the first oxide confinement layer and the second oxide confinement layer are respectively the predetermined oxide confinement layers.

9. The surface-emitting element according to claim 8, wherein, The center position of the first oxide confinement layer in the thickness direction is located on one side of the first surface side and the second surface side of the node position closest to the center position, and the center position of the second oxide confinement layer in the thickness direction is located on the other side of the first surface side and the second surface side of the node position closest to the center position.

10. The surface-emitting element according to claim 8, wherein, L1 represents the distance between the center position in the thickness direction of the first oxide confinement layer and the center position in the thickness direction of the light-emitting layer, L2 represents the distance between the center position in the thickness direction of the second oxide confinement layer and the center position in the thickness direction of the light-emitting layer, t1 represents the distance between the center position in the thickness direction of the first oxide confinement layer and the node position closest to the center position, and t2 represents the distance between the center position in the thickness direction of the second oxide confinement layer and the node position closest to the center position, and satisfies L1=(2n-1)λ / 4+t1 and L2=(2m-1)λ / 4+t2 or L1=(2n-1)λ / 4-t1 and L2=(2m-1)λ / 4-t2 where n and m are natural numbers.

11. The surface-emitting element according to claim 10, wherein, t1 = t2.

12. The surface-emitting element according to claim 8, wherein, The distance between the center position of the first oxide confinement layer in the thickness direction and the center position of the light-emitting layer in the thickness direction is equal to the distance between the center position of the second oxide confinement layer in the thickness direction and the center position of the light-emitting layer in the thickness direction.

13. The surface-emitting element according to claim 7, wherein, One of the first oxide confinement layer and the second oxide confinement layer is the predetermined oxide confinement layer.

14. The surface-emitting element according to claim 13, wherein, The center position in the thickness direction of one of the first oxide confinement layer and the second oxide confinement layer is located on the first surface side or the second surface side of the node position closest to the center position, and the center position in the thickness direction of the other of the first oxide confinement layer and the second oxide confinement layer coincides with the node position.

15. The surface-emitting element according to claim 13, wherein, L1 represents the distance between the center position in the thickness direction of one of the first oxide confinement layer and the center position in the thickness direction of the light-emitting layer, L2 represents the distance between the center position in the thickness direction of the other of the first oxide confinement layer and the center position in the thickness direction of the light-emitting layer, and t represents the distance between the center position in the thickness direction of one of the first oxide confinement layer and the node position closest to the center position, and satisfies L1=(2n-1)λ / 4+t and L2=(2m-1)λ / 4 or L1=(2n-1)λ / 4-t and L2=(2m-1)λ / 4 where n and m are natural numbers.

16. The surface-emitting element according to claim 13, wherein, The distance between the center position of the first oxide confinement layer in the thickness direction and the center position of the light-emitting layer in the thickness direction is different from the distance between the center position of the second oxide confinement layer in the thickness direction and the center position of the light-emitting layer in the thickness direction.

17. The surface-emitting element according to claim 1, wherein, Each of the plurality of oxide confinement layers includes: a non-oxidized region; and an oxidized region surrounding the non-oxidized region, wherein the non-oxidized region includes Al. x Ga 1-x As (0.8≤x≤1).

18. The surface-emitting element according to claim 1, wherein, The at least one light-emitting layer comprises a plurality of light-emitting layers stacked on top of each other, and the surface light-emitting element further comprises a tunnel junction layer disposed between at least two adjacent light-emitting layers forming a pair among the plurality of light-emitting layers.

19. The surface-emitting element according to claim 18, wherein, The predetermined oxide confinement layer is arranged between one of the two adjacent light-emitting layers and the tunnel junction layer.

20. The surface-emitting element according to claim 18, wherein, The predetermined position in the thickness direction of the tunnel layer coincides with the node position.

Images