Surface-emitting laser and manufacturing method therefor

Abstract

To provide a surface-emitting laser with which it is possible to improve characteristics and a manufacturing method therefor.SOLUTION: According to an embodiment, a surface-emitting laser includes first and second electrodes, a luminous layer, and first and second crystalline layers. The first crystalline layer is provided between the luminous layer and the second electrodes. The first crystalline layer includes a first subregion and a second subregion. The second crystalline layer includes a plurality of structures. The plurality of structures are provided between the luminous layer and the first subregion. At least a section of the second subregion is provided between the plurality of structures. One of the plurality of structures includes a first region and a second region provided between the first region and the first subregion. The concentration of a first element in the second subregion is higher than the concentration of the first element in the second region. Or, the second subregion includes the first element and the second region does not include the first element. The refractive index of the first region is higher than the refractive index of the second subregion.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a surface-emitting laser and a method for manufacturing the same.

Background Art

[0002] For example, optical elements such as photonic crystals are used in surface-emitting lasers. Improvement in characteristics is desired in surface-emitting lasers.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Embodiments provide a surface-emitting laser capable of improving characteristics and a method for manufacturing the same.

Means for Solving the Problems

[0005] According to an embodiment, a surface-emitting laser includes a first electrode, a second electrode, a light-emitting layer, a first crystal layer, and a second crystal layer. The light-emitting layer is provided between the first electrode and the second electrode. The first crystal layer is provided between the light-emitting layer and the second electrode. The first crystal layer includes a first partial region and a second partial region. The second crystal layer includes a plurality of structures. At least a part of the plurality of structures are arranged in a second direction intersecting a first direction from the first electrode to the second electrode. The plurality of structures are provided between the light-emitting layer and the first partial region in the first direction. At least a part of the second partial region is provided between the plurality of structures in the second direction. One of the plurality of structures includes a first region and a second region provided between the first region and the first partial region. The concentration of a first element in the second partial region is higher than the concentration of the first element in the second region. Or, the second partial region contains the first element and the second region does not contain the first element. The refractive index of the first region is higher than the refractive index of the second partial region.

Brief Description of the Drawings

[0006]

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BEST MODE FOR CARRYING OUT THE INVENTION

[0007] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio of the sizes between parts, etc. are not necessarily the same as the actual ones. Even when representing the same part, there are cases where the dimensions and ratios are represented differently in the drawings. In the present specification and each figure, the same reference numerals are given to the same elements as those described above with respect to the previously shown figures, and the detailed description is appropriately omitted.

[0008] (First Embodiment) FIG. 1 is a schematic cross-sectional view illustrating a surface-emitting laser according to the first embodiment. FIG. 2 is a schematic plan view illustrating a part of the surface-emitting laser according to the first embodiment. As shown in FIG. 1, the surface-emitting laser 110 according to the embodiment includes a first electrode 51, a second electrode 52, a light-emitting layer 11E, a first crystal layer 21, and a second crystal layer 22.

[0009] The light-emitting layer 11E is provided between the first electrode 51 and the second electrode 52. The first crystal layer 21 is provided between the light-emitting layer 11E and the second electrode 52. The light-emitting layer 11E is, for example, an active layer. The first crystal layer 21 includes a first partial region 21a and a second partial region 21b.

[0010] The first direction D1 from the first electrode 51 to the second electrode 52 is in the Z-axis direction. One direction perpendicular to the Z-axis direction is the X-axis direction. A direction perpendicular to both the Z-axis direction and the X-axis direction is the Y-axis direction.

[0011] The second crystal layer 22 includes a plurality of structures 22S. At least a part of the plurality of structures 22S are arranged in a second direction D2 that intersects the first direction D1.

[0012] FIG. 2 illustrates a plurality of structures 22S. As shown in FIG. 2, the plurality of structures 22S may be two-dimensionally arranged in a first plane PL1 that intersects the first direction D1. The plurality of structures 22S may be arranged along a third direction D3. The third direction D3 intersects a plane including the first direction D1 and the second direction D2. The planar shape of the plurality of structures 22S is arbitrary. The planar shape may be, for example, a polygon. At least a part of the plurality of structures 22S may be arranged with a first pitch. The pitch in one direction in the plurality of structures 22S and the pitch in another direction in the plurality of structures 22S may be different.

[0013] As shown in FIG. 1, the plurality of structures 22S are provided between the light-emitting layer 11E and the first partial region 21a in the first direction D1. As shown in FIG. 1, at least a part of the second partial region 21b is provided between the plurality of structures 22S in the second direction D2. As shown in FIG. 2, the second partial region 21b may be provided between the plurality of structures 22S in the first plane PL1.

[0014] As shown in FIG. 1, one of the plurality of structures 22S includes a first region 22a and a second region 22b. The second region 22b is provided between the first region 22a and the first partial region 21a.

[0015] In an embodiment, the first crystal layer 21 and the second crystal layer 22 are, for example, semiconductors.

[0016] In an embodiment, the concentration of the first element in the second partial region 21b is higher than the concentration of the first element in the second region 22b. Alternatively, the second partial region 21b contains the first element, and the second region 22b does not contain the first element. The first element is, for example, an impurity.

[0017] The refractive index of the first region 22a is higher than the refractive index of the second partial region 21b. The first region 22a and the second partial region 21b having different refractive indexes are arranged periodically. For example, the structure including the first region 22a and the second partial region 21b functions as a photonic crystal layer.

[0018] For example, light (electromagnetic wave) is emitted from the light-emitting layer 11E by a current based on a voltage applied between the first electrode 51 and the second electrode 52. The light is incident on, for example, the photonic crystal layer, and the traveling direction of the light changes. The light whose traveling direction has changed travels, for example, along a direction intersecting the light-emitting layer 11E. For example, light 81L (electromagnetic wave) including a component along the Z-axis direction is emitted to the outside. The light beam of the light 81L is planar. The wavelength of the light 81L may be, for example, 3 μm or more and 10 μm or less. Hereinafter, an electromagnetic wave of 3 μm or more and 10 μm or less will also be described as "light".

[0019] In the photonic crystal layer, the difference between the refractive index of the first region 22a and the refractive index of the second partial region 21b is preferably large. Thereby, the traveling direction of light can be controlled with higher efficiency.

[0020] In an embodiment, a photonic crystal layer is provided between the light-emitting layer 11E and the second electrode 52. The current flows through the first crystal layer 21 and the second crystal layer 22 to the light-emitting layer 11E. In an embodiment, the concentration of the first element in the second partial region 21b is higher than the concentration of the first element in the second region 22b. Alternatively, the second partial region 21b contains the first element, and the second region 22b does not contain the first element. Thereby, the current preferentially flows through the second partial region 21b. On the other hand, the current hardly flows through the second region 22b and also hardly flows through the first region 22a. The current path is controlled. For example, current constriction occurs.

[0021] In the second partial region 21b where current preferentially flows, due to the flow of carriers, the effective refractive index of the second partial region 21b decreases. As a result, when current is flowing, the difference between the refractive index of the second partial region 21b and the refractive index of the first region 22a increases. This enables light control with higher efficiency. According to the embodiment, a surface light-emitting laser capable of improving characteristics can be provided.

[0022] For example, when no current (carriers) is flowing, if a semiconductor crystal is doped with a first element such as Si, the refractive index of the semiconductor crystal increases. On the other hand, when carriers flow through the semiconductor crystal doped with the first element, the refractive index decreases due to the flow of carriers. In the embodiment, a high-density current flows through the second partial region 21b due to current constriction. As a result, the effect of refractive index decrease by carriers exceeds the effect of refractive index increase due to the first element doping. Consequently, the effective refractive index decreases. In the embodiment, the effect of refractive index decrease caused by the flow of carriers is effectively utilized.

[0023] For example, the conductivity of the second region 22b with a low concentration of the first element is lower than the conductivity of the second partial region 21b with a high concentration of the first element. The second region 22b functions as, for example, a current suppression layer. The second region 22b may function as, for example, a current blocking layer.

[0024] In one example, the first crystal layer 21 contains InP. The first element contains at least one selected from the group consisting of Si and Fe. The concentration of the first element in the first crystal layer 21 (for example, the second partial region 21b) may be 5 times or more and 1000 times or less the concentration of the first element in the second region 22b. The concentration of the first element in the first crystal layer 21 (for example, the second partial region 21b) may also be 10000 times or less the concentration of the first element in the second region 22b.

[0025] In one example, the concentration of the first element in the first crystal layer 21 (for example, the second partial region 21b) is, for example, 5×10 16 cm -31×10 or less 19 cm -3 Specifically, if the concentration of the first element in the first crystal layer 21 is excessively high, light absorption tends to increase.

[0026] For example, the concentration of the first element in the second region 22b may be, for example, 1×10 16 cm -3 or less.

[0027] In an embodiment, the first region 22a may contain, for example, InGaAs. The second region 22b contains InP. The second region 22b may contain, for example, undoped InP. For example, the conductivity of the second region 22b is lower than the conductivity of the second sub-region 21b. The second region 22b is, for example, a high-resistance region. The second sub-region 21b is, for example, a low-resistance region.

[0028] In an embodiment, the concentration of the first element in the first region 22a may be higher than the concentration of the first element in the second region 22b. Alternatively, the first region 22a may contain the first element, and the second region 22b may not contain the first element. As already described, it is difficult for current to flow through the first region 22a. Therefore, even when the first region 22a contains the first element, in the first region 22a, a decrease in the refractive index due to carriers does not substantially occur. Therefore, an increase in the refractive index due to the first region 22a containing the first element effectively occurs. By the first region 22a (for example, InGaAs) containing the first element (for example, Si), a higher refractive index can be easily obtained in the first region 22a (for example, InGaAs) compared to the case where it does not contain the element. As a result, the difference in refractive index between the first region 22a and the second sub-region 21b can be increased.

[0029] As shown in FIG. 1, the thickness of the first region 22a along the first direction D1 is defined as the first thickness t1. The thickness of the second region 22b along the first direction D1 is defined as the second thickness t2. In an embodiment, it is preferable that the second thickness t2 is thinner than the first thickness t1. Since the first thickness t1 is large, light can be controlled with high efficiency.

[0030] In one example, the second thickness t2 may be 100 nm or more and 300 nm or less. If the second thickness t2 is excessively thin, it becomes difficult to control the current. If the second thickness t2 is excessively thick, it becomes difficult to obtain high crystallinity.

[0031] In one example, the first thickness t1 may be 500 nm or more and 1500 nm or less. If the first thickness t1 is excessively thin, it becomes difficult to control the light. If the first thickness t1 is excessively thick, it becomes difficult to obtain high crystallinity.

[0032] As shown in FIG. 1, the surface-emitting laser 110 may further include a first cladding layer 11C. The first cladding layer 11C is provided between the first electrode 51 and the light-emitting layer 11E. For example, the light-emitting layer 11E is provided between a part 11p of the first cladding layer 11C and the second crystal layer 22. A ridge structure can be obtained, for example, by the part 11p of the first cladding layer 11C. In one example, the thickness of the first cladding layer 11C may be 3 μm or more and 5 μm or less.

[0033] For example, the refractive index of the first cladding layer 11C is lower than that of the light-emitting layer 11E. The first cladding layer 11C includes, for example, InP. The first crystal layer 21 may function as, for example, a second cladding layer.

[0034] The light-emitting layer 11E includes an AlInAs film and an InGaAs film. These films are provided alternately along the first direction D1. For example, the thickness of the light-emitting layer 11E is 1 μm or more and 2 μm or less. The light-emitting layer 11E emits light by intersubband transition. The surface-emitting laser 110 may be, for example, a surface-emitting quantum cascade laser (QCL). The wavelength of the light 81L may be, for example, 3 μm or more and 10 μm or less.

[0035] As shown in FIG. 1, the surface-emitting laser 110 may include a substrate 10s. The substrate 10s is provided between the first electrode 51 and the first cladding layer 11C. The substrate 10s may be, for example, an InP substrate or the like. The light 81L is emitted from one surface of the substrate 10s.

[0036] As shown in FIG. 1, an insulating film 31i may be provided between the second electrode 52 and a part of the first crystal layer 21. The insulating film 31i may contain, for example, silicon oxide or the like. The surface-emitting laser 110 may include a reflective film 31. The directions from the light-emitting layer 11E to the reflective film 31, from the first crystal layer 21 to the reflective film 31, and from the second crystal layer 22 to the reflective film 31 intersect the first direction D1. A part of the insulating film 31i may be provided between the light-emitting layer 11E and the reflective film 31, between the first crystal layer 21 and the reflective film 31, and between the second crystal layer 22 and the reflective film 31.

[0037] FIG. 3 is a schematic cross-sectional view illustrating a surface-emitting laser according to the first embodiment. As shown in FIG. 3, in the surface-emitting laser 111 according to the embodiment, one of the plurality of structures 22S further includes a third region 22c. In this example, the second crystal layer 22 further includes a first planar region 22L. The configuration of the surface-emitting laser 111 excluding these may be the same as the configuration of the surface-emitting laser 110.

[0038] The first region 22a is provided between a part of the first planar region 22L and the second region 22b. The second partial region 21b is provided between another part of the first planar region 22L and the second electrode 52. The concentration of the first element in the first planar region 22L may be higher than the concentration of the first element in the second region 22b. Alternatively, the first planar region 22L contains the first element and the second region 22b does not contain the first element. The first planar region 22L contains InP containing the first element (for example, Si).

[0039] The third region 22c is provided between the first planar region 22L and the first region 22a. For example, the concentration of the first element in the third region 22c may be lower than the concentration of the first element in the second partial region 21b. Alternatively, the second partial region 21b contains the first element and the third region 22c does not contain the first element. The third region 22c contains, for example, undoped InP.

[0040] For example, the concentration of the first element in the third region 22c may be lower than the concentration of the first element in the first region 22a. Or, the first region 22a may contain the first element, and the third region 22c may not contain the first element. The third region 22c is, for example, a high-resistance region.

[0041] By providing the third region 22c, the current flows more efficiently through the second partial region 21b. A high refractive index difference can be stably obtained.

[0042] As shown in FIG. 3, let the thickness along the first direction D1 of the third region 22c be the third thickness t3. The third thickness t3 may be, for example, 100 nm or more and 300 nm or less.

[0043] The first planar region 22L may function, for example, as an etching stopper during the processing of the plurality of structures 22S. The first planar region 22L may also have a function of spreading the current flowing through the second partial region 21b.

[0044] FIG. 4 is a schematic cross-sectional view illustrating a surface-emitting laser according to the first embodiment. As shown in FIG. 4, in the surface-emitting laser 112 according to the embodiment, one of the plurality of structures 22S further includes a fourth region 22d. The configuration of the surface-emitting laser 112 except for this may be the same as the configuration of the surface-emitting laser 110.

[0045] The fourth region 22d is provided between the second partial region 21b and the first region 22a in the second direction D2. The fourth region 22d may be provided between the second partial region 21b and the first region 22a in the first plane PL1. The concentration of the first element in the second partial region 21b is higher than the concentration of the first element in the fourth region 22d. Or, the second partial region 21b contains the first element, and the fourth region 22d does not contain the first element. By providing such a fourth region 22d, the current flows more efficiently concentrated through the second partial region 21b. A large refractive index difference can be efficiently obtained.

[0046] The fourth region 22d may include, for example, undoped InP. As shown in FIG. 4, in this example, the fourth region 22d is continuous with the second region 22b.

[0047] (Second Embodiment) The second embodiment relates to a method for manufacturing a surface emitting laser. FIGS. 5 to 7 are schematic cross-sectional views illustrating a method for manufacturing a surface emitting laser according to the second embodiment. As shown in FIG. 5, a processed body 22x is formed on a first planar region film 22Lf provided on the light emitting layer 11E. The processed body 22x includes a first region 22a and a second region 22b above the first region 22a. The light emitting layer 11E may be provided on a first cladding layer 11C provided on a substrate 10s. The processed body 22x may be formed, for example, by epitaxial growth. The first planar region film 22Lf becomes the first planar region 22L.

[0048] As shown in FIG. 6, a part of the processed body 22x is removed to expose a part of the first planar region film 22Lf, thereby forming a recess 22D.

[0049] As shown in FIG. 7, a first crystal layer 21 is formed in the recess 22D and on the second region 22b.

[0050] In the embodiment, the concentration of the first element in the first crystal layer 21 is higher than the concentration of the first element in the second region 22b. Alternatively, the first crystal layer 21 contains the first element, and the second region 22b does not contain the first element. The refractive index of the first region 22a is higher than the refractive index of the first crystal layer 21.

[0051] After the above processing, by forming a ridge portion, an insulating film 31i, a second electrode 52, and a first electrode 51, for example, a surface emitting laser 110 or a surface emitting laser 111 can be obtained. By the above manufacturing method, a smooth surface emitting laser with improved characteristics can be efficiently manufactured.

[0052] In this example, the first crystal layer 21 contains InP. The first element contains at least one selected from the group consisting of, for example, Si and Fe.

[0053] As shown in FIG. 5, the processed body 22x may further include a third region 22c. The third region 22c is provided between the first planar region film 22Lf and the first region 22a. In one example, the concentration of the first element in the third region 22c is higher than the concentration of the first element in the first crystal layer 21. Or, the first crystal layer 21 contains the first element, and the third region 22c does not contain the first element.

[0054] FIGS. 8 to 10 are schematic cross-sectional views illustrating a method of manufacturing a surface-emitting laser according to the second embodiment. As shown in FIG. 8, a processed body 22x including a first region 22a is formed on a first planar region film 22Lf provided on the light-emitting layer 11E. Further, a part of the processed body 22x is removed to form a recess 22D. In the recess 22D, a part of the first planar region film 22Lf and the side surface 22as of the first region 22a are exposed.

[0055] As shown in FIG. 9, a crystal film 23f is formed on a part of the first planar region film 22Lf (first planar region 22L), the side surface 22as of the first region 22a, and the remaining first region 22a. At least a part of the crystal film 23f becomes, for example, a fourth region 22d.

[0056] As shown in FIG. 10, a first crystal layer 21 is formed in the remaining space of the recess 22D. The first crystal layer 21 may be formed on the crystal film 23f. The concentration of the first element in the first crystal layer 21 is higher than the concentration of the first element in the crystal film 23f. Or, the first crystal layer 21 contains the first element, and the crystal film 23f does not contain the first element. The refractive index of the first region 22a is higher than the refractive index of the first crystal layer 21.

[0057] After the above processing, a surface-emitting laser 112, for example, is obtained by forming a ridge portion, forming an insulating film 31i, forming a second electrode 52, and forming a first electrode 51. By the above manufacturing method, a surface-emitting laser with improved characteristics can be efficiently manufactured.

[0058] In the above example, the first crystal layer 21 contains InP. The first element contains at least one selected from the group consisting of Si and Fe. The crystal film 23f contains InP.

[0059] The embodiment may include the following technical solutions. (Technical solution 1) A first electrode, A second electrode, A light-emitting layer provided between the first electrode and the second electrode, A first crystal layer provided between the light-emitting layer and the second electrode, the first crystal layer including a first partial region and a second partial region, the first crystal layer, A second crystal layer including a plurality of structures, at least a part of the plurality of structures being arranged in a second direction intersecting a first direction from the first electrode to the second electrode, the plurality of structures being provided between the light-emitting layer and the first partial region in the first direction, at least a part of the second partial region being provided between the plurality of structures in the second direction, one of the plurality of structures including a first region and a second region provided between the first region and the first partial region, the concentration of the first element in the second partial region being higher than the concentration of the first element in the second region, or the second partial region containing the first element and the second region not containing the first element, the refractive index of the first region being higher than the refractive index of the second partial region, the second crystal layer, A surface-emitting laser comprising.

[0060] (Technical solution 2) The first crystal layer contains InP, The first element contains at least one selected from the group consisting of Si and Fe, the surface-emitting laser according to Technical solution 1.

[0061] (Technical Solution 3) The first region contains InGaAs, The second region contains InP, and is a surface-emitting laser described in Technical Solution 2.

[0062] (Technical Solution 4) The conductivity of the second region is lower than that of the second partial region, and is a surface-emitting laser described in any one of Technical Solutions 1 to 3.

[0063] (Technical Solution 5) The second crystal layer further includes a first planar region, The first region is provided between a part of the first planar region and the second region, The second partial region is provided between another part of the first planar region and the second electrode, and is a surface-emitting laser described in any one of Technical Solutions 1 to 4.

[0064] (Technical Solution 6) The concentration of the first element in the first planar region is higher than the concentration of the first element in the second region, or the first planar region contains the first element and the second region does not contain the first element, and is a surface-emitting laser described in Technical Solution 5.

[0065] (Technical Solution 7) One of the plurality of structures further includes a third region, The third region is provided between the first planar region and the first region, The concentration of the first element in the third region is lower than the concentration of the first element in the second partial region, or the second partial region contains the first element and the third region does not contain the first element, and is a surface-emitting laser described in Technical Solution 5 or 6.

[0066] (Technical Solution 8) The third thickness along the first direction of the third region is 100 nm or more and 300 nm or less, and is a surface-emitting laser described in Technical Solution 7.

[0067] (Technical Solution 9) The concentration of the first element in the first region is higher than the concentration of the first element in the second region, or the first region contains the first element and the second region does not contain the first element. The surface-emitting laser according to any one of Technical Solutions 1 to 8.

[0068] (Technical Solution 10) The second thickness along the first direction of the second region is thinner than the first thickness along the first direction of the first region. The surface-emitting laser according to any one of Technical Solutions 1 to 9.

[0069] (Technical Solution 11) The second thickness is 100 nm or more and 300 nm or less. The first thickness is 500 nm or more and 1500 nm or less. The surface-emitting laser according to Technical Solution 10.

[0070] (Technical Solution 12) One of the plurality of structures further includes a fourth region. The fourth region is provided between the second partial region and the first region in the second direction. The concentration of the first element in the second partial region is higher than the concentration of the first element in the fourth region, or the second partial region contains the first element and the fourth region does not contain the first element. The surface-emitting laser according to any one of Technical Solutions 1 to 11.

[0071] (Technical Solution 13) The fourth region is continuous with the second region. The surface-emitting laser according to Technical Solution 12.

[0072] (Technical Solution 14) Further includes a first cladding layer provided between the first electrode and the light-emitting layer. The light-emitting layer is provided between a part of the first cladding layer and the second crystal layer. The surface-emitting laser according to any one of Technical Solutions 1 to 13.

[0073] (Technical Solution 15) The light-emitting layer is a surface-emitting laser according to any one of Technical Solutions 1 to 14 that emits light by inter-subband transition.

[0074] (Technical Solution 16) On the first planar region film provided on the light-emitting layer, a processed body including a first region and a second region above the first region is formed. A part of the processed body is removed to expose a part of the first planar region film to form a concave portion. A first crystal layer is formed in the concave portion and on the second region. The concentration of the first element in the first crystal layer is higher than the concentration of the first element in the second region, or the first crystal layer contains the first element and the second region does not contain the first element. The refractive index of the first region is higher than the refractive index of the first crystal layer. A method for manufacturing a surface-emitting laser.

[0075] (Technical Solution 17) The first crystal layer contains InP. The first element contains at least one selected from the group consisting of Si and Fe. A method for manufacturing a surface-emitting laser according to Technical Solution 16.

[0076] (Technical Solution 18) The processed body further includes a third region provided between the first planar region film and the first region. The concentration of the first element in the third region is higher than the concentration of the first element in the first crystal layer, or the first crystal layer contains the first element and the third region does not contain the first element. A method for manufacturing a surface-emitting laser according to Technical Solution 16 or 17.

[0077] (Technical Solution 19) On the first planar region film provided on the light-emitting layer, a processed body including a first region is formed. A part of the processed body is removed to form a concave portion, and in the concave portion, a part of the first planar region film and the side surface of the first region are exposed. Form a crystal film on a part of the first planar region film, a side surface of the first region, and the remaining first region. Form a first crystal layer in a remaining space of the recess. A concentration of a first element in the first crystal layer is higher than a concentration of the first element in the crystal film, or the first crystal layer contains the first element and the crystal film does not contain the first element. A refractive index of the first region is higher than a refractive index of the first crystal layer. A method of manufacturing a surface emitting laser.

[0078] (Technical proposal 20) The first crystal layer contains InP. The first element contains at least one selected from the group consisting of Si and Fe. A method of manufacturing a surface emitting laser according to Technical proposal 19.

[0079] According to an embodiment, a surface emitting laser capable of improving characteristics and a method of manufacturing the same can be provided.

[0080] In the present specification, "vertical" and "parallel" include not only strict vertical and strict parallel, but also, for example, variations in a manufacturing process, and may be substantially vertical and substantially parallel.

[0081] As described above, embodiments of the present invention have been described with reference to specific examples. However, the present invention is not limited to these specific examples. For example, with respect to specific configurations of each element such as an electrode, a light emitting layer, and a crystal layer included in the surface emitting laser, the present invention can be similarly implemented by appropriately selecting from a range known to those skilled in the art, and as long as similar effects can be obtained, it is included in the scope of the present invention.

[0082] In addition, a combination of any two or more elements of each specific example within a technically possible range is also included in the scope of the present invention as long as it includes the gist of the present invention.

[0083] In addition, based on the surface-emitting laser described above as an embodiment of the present invention, all surface-emitting lasers that can be appropriately designed and modified by those skilled in the art also belong to the scope of the present invention as long as they encompass the gist of the present invention.

[0084] In addition, within the scope of the idea of the present invention, those skilled in the art can conceive of various modification examples and correction examples, and it is understood that those modification examples and correction examples also belong to the scope of the present invention.

[0085] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0086] 10s: Substrate, 11C: First cladding layer, 11E: Light-emitting layer, 21, 22: First and second crystal layers, 21a, 21b: First and second partial regions, 22D: Recess, 22L: First planar region, 22Lf: First planar region film, 22S: Structure, 22a - 22d: First - fourth regions, 22as: Side surface, 22x: Processed body, 23f: Crystal film, 31: Reflective film, 31i: Insulating film, 51, 52: First and second electrodes, 81L: Light, 110, 111, 112: Surface-emitting lasers, D1 - D3: First - third directions, PL1: First plane, t1 - t3: First - third thicknesses

Claims

1. a first electrode, a second electrode, a light-emitting layer provided between the first electrode and the second electrode, a first crystal layer provided between the light-emitting layer and the second electrode, the first crystal layer including a first partial region and a second partial region, the first crystal layer, a second crystal layer including a plurality of structures, at least a part of the plurality of structures being arranged in a second direction intersecting a first direction from the first electrode to the second electrode, the plurality of structures being provided between the light-emitting layer and the first partial region in the first direction, at least a part of the second partial region being provided between the plurality of structures in the second direction, one of the plurality of structures including a first region and a second region provided between the first region and the first partial region, the concentration of a first element in the second partial region being higher than the concentration of the first element in the second region, or the second partial region including the first element and the second region not including the first element, the refractive index of the first region being higher than the refractive index of the second partial region, the second crystal layer, A surface-emitting laser comprising the above.

2. The first crystal layer includes InP, The first element includes at least one selected from the group consisting of Si and Fe. The surface-emitting laser according to claim 1.

3. The first region includes InGaAs, The second region includes InP. The surface-emitting laser according to claim 2.

4. The second crystal layer further includes a first planar region, The first region is provided between a part of the first planar region and the second region, The second partial region is provided between another part of the first planar region and the second electrode. The surface-emitting laser according to any one of claims 1 to 3.

5. The concentration of the first element in the first planar region is higher than the concentration of the first element in the second region, or the first planar region includes the first element and the second region does not include the first element. The surface-emitting laser according to claim 4.

6. The one of the plurality of structures further includes a third region, The third region is provided between the first planar region and the first region, The concentration of the first element in the third region is lower than the concentration of the first element in the second partial region, or the second partial region contains the first element and the third region does not contain the first element. The surface-emitting laser according to claim 4.

7. The second thickness along the first direction of the second region is thinner than the first thickness along the first direction of the first region. The surface-emitting laser according to any one of claims 1 to 3.

8. One of the plurality of structures further includes a fourth region, The fourth region is provided between the second partial region and the first region in the second direction, The concentration of the first element in the second partial region is higher than the concentration of the first element in the fourth region, or the second partial region contains the first element and the fourth region does not contain the first element. The surface-emitting laser according to any one of claims 1 to 3.

9. Form a processed body including a first region and a second region above the first region on a first planar region film provided on the light-emitting layer, Remove a part of the processed body to expose a part of the first planar region film to form a recess, Form a first crystal layer in the recess and on the second region, The concentration of the first element in the first crystal layer is higher than the concentration of the first element in the second region, or the first crystal layer contains the first element and the second region does not contain the first element, The refractive index of the first region is higher than the refractive index of the first crystal layer. A method for manufacturing a surface-emitting laser.

10. Form a processed body including a first region on a first planar region film provided on the light-emitting layer, Remove a part of the processed body to form a recess, and in the recess, a part of the first planar region film and the side surface of the first region are exposed, Form a crystal film on the part of the first planar region film, the side surface of the first region, and the remaining first region, Form a first crystal layer in the remaining space of the recess, The concentration of the first element in the first crystal layer is higher than the concentration of the first element in the crystal film, or the first crystal layer contains the first element and the crystal film does not contain the first element, The refractive index of the first region is higher than the refractive index of the first crystal layer. A method for manufacturing a surface-emitting laser.

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