Surface emitting laser device

Abstract

To reduce an internal stress.SOLUTION: A first light reflective layer 40 includes a plurality of first reflective layer 41 and a plurality of second reflective layers 42 which are made of a material containing Al and alternately arranged in a Z-axis direction. An Al composition ratio β1 of the first reflective layer 41 is higher than an Al composition ratio β2 of the second reflective layer 42. A laminated structure of the first reflective layer 41 and the second reflective layer 42 is provided at a position overlapping with a passing layer 531. The first light reflective layer 40 includes a light-emitting unit side surface 512 which is an end surface in a direction perpendicular to the Z-axis direction, and a first region 441 provided between the light-emitting unit side surface 512 and an end portion of an opening 731 of an insulating film 73 in planar view. The first region 441 contains Al and Zn, and has a lower Al composition ratio than that of the first reflective layer 41.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a surface emitting laser device. [Background technology]

[0002] Patent Document 1 discloses a surface-emitting laser device. This surface-emitting laser device includes a substrate made of a compound semiconductor material, and an n-type semiconductor layer, an active layer, and a p-type semiconductor layer stacked on the substrate. The n-type semiconductor layer includes an n-type light reflecting layer, and the p-type semiconductor layer includes a p-type light reflecting layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-21879 A

[0004] [overview] However, in a surface-emitting laser device, internal stress may affect the characteristics of the surface-emitting laser device, and therefore there is a need to suppress the internal stress.

[0005] A surface-emitting laser device according to one embodiment of the present disclosure includes a light generating layer, a first light reflecting layer and a second light reflecting layer made of a material containing Al and arranged on either side of the light generating layer in a thickness direction of the light generating layer, an insulating film provided on a top surface of the first light reflecting layer and having an opening exposing a portion of an upper surface of the first light reflecting layer, a first electrode provided across the insulating film and the first light reflecting layer and electrically connected to the first light reflecting layer, a second electrode electrically connected to the second light reflecting layer, a passing layer disposed between the second light reflecting layer and the second electrode and configured to allow a current to pass through, and an oxide layer surrounding the passing layer. and a current confinement layer comprising: a first light reflective layer made of a material containing Al and comprising a plurality of first reflective layers and a plurality of second reflective layers arranged alternately in the thickness direction, the first light reflective layer having a higher Al composition ratio than the second reflective layer, a stacked structure of the first reflective layers and the second reflective layers being provided at a position overlapping the passing layer, the first light reflective layer comprising a side which is an end face in a direction perpendicular to the thickness direction, and a first region which is provided between the side face and an end of the opening of the insulating film as viewed from the thickness direction, which contains Al and Zn, and has a lower Al composition ratio than the first reflective layer. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic plan view of a surface emitting laser device according to one embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the surface emitting laser device taken along the line F2-F2 in FIG. [Diagram 3] FIG. 3 is a schematic cross-sectional view showing an enlarged portion of the surface-emitting laser device of FIG. [Figure 4] FIG. 4 is a schematic plan view showing an enlarged portion of the surface-emitting laser device of FIG. [Diagram 5] FIG. 5 is a schematic cross-sectional view showing the layer configuration of the first light reflecting layer and the second light reflecting layer. [Figure 6] FIG. 6 is a schematic cross-sectional view illustrating the relationship between the insulating film, the first region, the first electrode, and the current confinement layer. [Figure 7]FIG. 7 is a schematic cross-sectional view showing a surface-emitting laser device of a comparative example. [Figure 8] FIG. 8 is an explanatory diagram illustrating the reflective layer in the light reflective layer. [Figure 9] FIG. 9 is an explanatory diagram illustrating the reflective layer in the light reflective layer. [Figure 10] 10A to 10C are schematic cross-sectional views showing an example of a manufacturing process for the surface emitting laser device of FIG. [Figure 11] FIG. 11 is a schematic cross-sectional view showing a manufacturing process subsequent to FIG. [Figure 12] FIG. 12 is a schematic cross-sectional view showing a manufacturing process subsequent to FIG. [Figure 13] FIG. 13 is a schematic cross-sectional view showing a manufacturing process subsequent to FIG. [Figure 14] FIG. 14 is a schematic cross-sectional view showing a manufacturing process subsequent to FIG. [Figure 15] FIG. 15 is a schematic cross-sectional view showing a manufacturing process subsequent to FIG. [Figure 16] FIG. 16 is a schematic plan view of a surface emitting laser device according to a modified example.

[0007] [Detailed Description] Hereinafter, some embodiments of the surface-emitting laser device of the present disclosure will be described with reference to the accompanying drawings. Note that for simplicity and clarity of description, components shown in the drawings are not necessarily drawn to scale. Also, hatching lines may be omitted in cross-sectional views to facilitate understanding. The accompanying drawings are merely illustrative of embodiments of the present disclosure and should not be considered as limiting the present disclosure. Terms such as "first", "second", and "third" in the present disclosure are used merely to distinguish objects and do not rank the objects.

[0008] The following detailed description includes devices, systems, and methods embodying exemplary embodiments of the present disclosure. This detailed description is merely illustrative in nature and is not intended to limit the embodiments of the present disclosure or the application and uses of such embodiments.

[0009] The term "at least one" as used herein means "one or more" of the desired options. As an example, the term "at least one" as used herein means "only one option" or "both of two options" if the number of options is two. As another example, the term "at least one" as used herein means "only one option" or "any combination of two or more options" if the number of options is three or more.

[0010] (Schematic configuration of a surface emitting laser device) FIG. 1 is a schematic plan view of a surface-emitting laser device 10 according to an embodiment. FIG. 2 is a cross-sectional view of the surface-emitting laser device 10 taken along the line F2-F2 in FIG. 1. FIG. 3 is a schematic cross-sectional view showing an enlarged portion of the surface-emitting laser device 10 in FIG. 2. FIG. 4 is a schematic cross-sectional view showing an enlarged portion of the surface-emitting laser device 10 in FIG. 2. FIG. 4 is a schematic plan view showing an enlarged portion of the surface-emitting laser device 10 in FIG. 1, and is a schematic plan view showing the relationship between the light-emitting section 51, the connection section 711 and the opening 712 of the first electrode 71, the passing layer 531 of the current confinement layer 53, and the first region 441. FIG. 5 is a schematic cross-sectional view showing the layer configuration of the first light reflection layer and the second light reflection layer. FIG. 6 is a schematic cross-sectional view explaining the relationship between the insulating film 73, the first region 441, the first electrode 71, and the current confinement layer 53.

[0011] 1 is a semiconductor laser device called a VCSEL (Vertical Cavity Surface Emitting Laser). The surface emitting laser device 10 has a roughly rectangular parallelepiped shape. In one example, the surface emitting laser device 10 has a rectangular plate shape.

[0012] The surface-emitting laser device 10 includes a device upper surface 11, a device lower surface 12, and a plurality of device side surfaces 13, 14, 15, and 16. The device upper surface 11 and the device lower surface 12 face in opposite directions. In the present disclosure, the direction in which the device upper surface 11 faces is defined as the thickness direction. The thickness direction of the surface-emitting laser device 10 is defined as the Z-axis direction. Two axial directions perpendicular to the Z-axis direction and perpendicular to each other are defined as the X-axis direction and the Y-axis direction. The term "planar view" used in the present disclosure refers to viewing an object from the thickness direction, that is, viewing from the Z-axis direction. In one example, the surface-emitting laser device 10 is rectangular in plan view, with the length in the Y-axis direction being shorter than the length in the X-axis direction. The shape of the surface-emitting laser device 10 in plan view can be changed arbitrarily. The device side surfaces 13 and 14 face in opposite directions to each other in the X-axis direction. The device side surfaces 15 and 16 face in opposite directions to each other in the Y-axis direction.

[0013] The surface-emitting laser device 10 includes a substrate 21 and a semiconductor layer 22 . In one example, the substrate 21 includes a compound semiconductor material. The substrate 21 includes, for example, a single crystal of a compound semiconductor material that forms a tetragonal crystal. The compound semiconductor material may be a III-V group semiconductor material. The substrate 21 is, for example, a GaAs single crystal substrate that includes a first conductivity type impurity or a second conductivity type impurity different from the first conductivity type. In one example, the first conductivity type is p-type, and the second conductivity type is n-type. In one example, the substrate 21 is a semiconductor substrate that includes a second conductivity type impurity. The substrate 21 may be a substrate that is made of material other than GaAs. The n-type impurity may be, for example, Si (silicon). The substrate 21 includes a first substrate surface 211 and a second substrate surface 212 that face in opposite directions in the Z-axis direction. In one example, the second substrate surface 212 constitutes the device lower surface 12.

[0014] The semiconductor layer 22 is formed on the first substrate surface 211 of the substrate 21. The semiconductor layer 22 includes a first surface 221 and a second surface 222. The first surface 221 and the second surface 222 face in opposite directions in the Z-axis direction. The first surface 221 of the semiconductor layer 22 faces the same direction as the first substrate surface 211 of the substrate 21. The second surface 222 of the semiconductor layer 22 faces the first substrate surface 211 of the substrate 21. The second surface 222 of the semiconductor layer 22 contacts the first substrate surface 211 of the substrate 21. In one example, the first surface 221 of the semiconductor layer 22 constitutes the device top surface 11.

[0015] Semiconductor layer 22 includes light generating layer 30, first light reflecting layer 40, and second light reflecting layer 60. First light reflecting layer 40 and second light reflecting layer 60 are arranged to sandwich light generating layer 30 in the Z-axis direction. In one example, first light reflecting layer 40 is arranged on the opposite side of substrate 21 with respect to light generating layer 30. In one example, second light reflecting layer 60 is arranged on the substrate 21 side with respect to light generating layer 30. In one example, second light reflecting layer 60, light generating layer 30, and first light reflecting layer 40 are stacked in this order on first substrate surface 211 of substrate 21. Semiconductor layer 22 may include an intermediate layer in contact with first substrate surface 211 of substrate 21. The intermediate layer may include, for example, a buffer layer.

[0016] The surface-emitting laser device 10 includes a first electrode 71 and a second electrode 72. In one example, the first electrode 71 is a p-side electrode, and the second electrode 72 is an n-side electrode. The first electrode 71 is provided on the opposite side of the first light reflecting layer 40 to the second light reflecting layer 60. The first light reflecting layer 40 includes a first surface 401 facing the Z-axis direction. The first surface 401 of the first light reflecting layer 40 constitutes the first surface 221 of the semiconductor layer 22. The first electrode 71 is provided on the first surface 401 of the first light reflecting layer 40. The first electrode 71 is electrically connected to the first light reflecting layer 40. In detail, the surface-emitting laser device 10 includes an insulating film 73 formed on the first surface 401 of the first light reflecting layer 40, and the insulating film 73 may be formed so as to expose the peripheral portion of the first surface 401 of the first light reflecting layer 40 constituting the device upper surface 11. The first electrode 71 is provided on the insulating film 73. The first electrode 71 may be formed so as to expose the peripheral portion of the insulating film 73. The first electrode 71 may include an external connection portion 714. The external connection portion 714 connects the surface-emitting laser device 10 to the outside, and a conductor such as a bonding wire is connected to the external connection portion 714. Note that an external terminal electrically connected to the external connection portion 714 may be provided on the external connection portion 714, and a conductor such as a bonding wire may be connected to the external terminal.

[0017] The second electrode 72 is provided on the second light reflecting layer 60 on the opposite side to the first light reflecting layer 40. The second electrode 72 may be provided on the entire lower surface 12 of the device. The surface-emitting laser device 10 includes a substrate 21. The second electrode 72 is provided on a second substrate surface 212 of the substrate 21. The second electrode 72 is electrically connected to the second light reflecting layer 60.

[0018] (Photogenerating Layer) The light generating layer 30 includes an active layer 31. The active layer 31 is disposed between the first light reflecting layer 40 and the second light reflecting layer 60 in the Z-axis direction. The active layer 31 is a light emitting layer that emits light when a current is supplied thereto. In one example, the active layer 31 may have a QW (Quantum Well) structure including a quantum well layer and a barrier layer. The active layer 31 may have an MQW (Multi Quantum Well) structure in which quantum well layers and barrier layers are alternately stacked at any period. The quantum well layer may include GaAs (Gallium Arsenide), AlGaAs (Aluminum Gallium Arsenide), or InGaAs (Indium Gallium Arsenide). The quantum well layer may be undoped. The barrier layer may have a band gap larger than the band gap of the quantum well layer.

[0019] Light generating layer 30 may include a first cladding layer 32 and a second cladding layer 33. First cladding layer 32 and second cladding layer 33 are arranged to sandwich active layer 31. First cladding layer 32 is arranged on the first light reflecting layer 40 side with respect to active layer 31. First cladding layer 32 may contain an impurity of a first conductivity type. The first conductivity type may be, for example, p-type. The p-type impurity may be, for example, C (carbon). Second cladding layer 33 is arranged on the second light reflecting layer 60 side with respect to active layer 31. Second cladding layer 33 may contain an impurity of a second conductivity type. Second cladding layer 33 may contain, for example, Si as an n-type impurity.

[0020] The first cladding layer 32 and the second cladding layer 33 may include Al (aluminum). In one example, the first cladding layer 32 and the second cladding layer 33 include AlGaAs. The first cladding layer 32 is an AlGaAs layer having an Al composition ratio α1. α1 Ga (1-α1) The second cladding layer 33 contains As. The Al composition ratio α1 may be 0.2 or more and 0.7 or less. α2 Ga (1-α2)It contains As. The Al composition ratio α2 may be equal to or greater than 0.2 and equal to or less than 0.7. The Al composition ratios of the first cladding layer 32 and the second cladding layer 33 may be the same as or different from each other.

[0021] (First light reflecting layer and second light reflecting layer) The first light reflecting layer 40 is composed of a DBR layer (Distributed Bragg Reflector). The first light reflecting layer 40 may contain impurities of a first conductivity type. The first conductivity type may be, for example, p-type. The p-type impurities may be, for example, C. The first light reflecting layer 40 has a refractive index that changes periodically along the Z-axis direction, and resonantly reflects a specific wavelength component. It can be said that the first light reflecting layer 40 has a reflectance that reflects a specific wavelength component.

[0022] The second light reflecting layer 60 is composed of a DBR layer. The second light reflecting layer 60 may contain n-type impurities, which are the second conductive type. The second conductive type impurities may be, for example, Si. The second light reflecting layer 60 has a refractive index that changes periodically along the Z-axis direction, and resonantly reflects a specific wavelength component. It can be said that the second light reflecting layer 60 has a reflectance that reflects a specific wavelength component.

[0023] The reflectance of the first light reflecting layer 40 and the reflectance of the second light reflecting layer 60 may be different from each other. In one example, the reflectance of the second light reflecting layer 60 is higher than the reflectance of the first light reflecting layer 40. The reflectance of the first light reflecting layer 40 and the reflectance of the second light reflecting layer 60 may be the same.

[0024] (Isolation groove and light-emitting part) The semiconductor layer 22 includes a separation groove 52. The number of the separation grooves 52 may be one or more than one. In one example, the semiconductor layer 22 includes a plurality of separation grooves 52. The separation grooves 52 are formed so as to be recessed from the first surface 221 of the semiconductor layer 22 toward the second surface 222 of the semiconductor layer 22. That is, it can be said that the separation grooves 52 are recessed in the Z-axis direction, which is the thickness direction, from the first surface 221 of the semiconductor layer 22. In one example, the separation grooves 52 extend from the first surface 221 of the semiconductor layer 22 through the first light reflecting layer 40 and the light generating layer 30 to the second light reflecting layer 60. As shown in FIG. 1 and FIG. 5, the separation grooves 52 are annular in plan view. In one example, the separation grooves 52 are annular. The shape of the separation grooves 52 in plan view may be any shape, such as a polygonal shape, an elliptical shape, or the like.

[0025] As shown in FIG. 2, separation groove 52 includes inner circumferential surface 521, outer circumferential surface 522, and bottom surface 523 connecting inner circumferential surface 521 and outer circumferential surface 522. First light reflecting layer 40 and light generating layer 30 are exposed on inner circumferential surface 521 and outer circumferential surface 522 of separation groove 52. A part of second light reflecting layer 60 is exposed on inner circumferential surface 521 and outer circumferential surface 522 of separation groove 52. Second light reflecting layer 60 is exposed on bottom surface 523 of separation groove 52. Separation groove 52 is recessed in the Z-axis direction with respect to first light reflecting layer 40. Therefore, inner circumferential surface 521 of separation groove 52 can be said to be an end surface in a direction perpendicular to the Z-axis direction. Furthermore, outer circumferential surface 522 of separation groove 52 can be said to be an end surface in a direction perpendicular to the Z-axis direction.

[0026] 1 and 2, the semiconductor layer 22 includes a light emitting portion 51 surrounded by an isolation trench 52. The light emitting portion 51 may be partitioned into a plateau shape (mesa shape) by the isolation trench 52. The light emitting portion 51 may have any shape, such as a cylindrical shape. As shown in FIG. 1, the semiconductor layer 22 may include a plurality of light emitting portions 51.

[0027] The light emitting sections 51 are arranged at intervals from each other in the X-axis direction and the Y-axis direction in a plan view. In one example, the light emitting sections 51 are arranged in a staggered manner in a plan view. In particular, the light emitting sections 51 are arranged such that one light emitting section 51 is located at each of the three vertices of a triangle (for example, an equilateral triangle) in a plan view. It can also be said that the light emitting sections 51 are arranged such that one light emitting section 51 is located at each of the six vertices of a hexagon (for example, a regular hexagon) in a plan view. The light emitting sections 51 can be arranged in any manner, such as in a matrix or radial (concentric) pattern.

[0028] As shown in FIG. 2, light-emitting section 51 includes light-emitting section surface 511 constituting a part of first surface 221 of semiconductor layer 22. Light-emitting section 51 also includes light-emitting section side surface 512 constituting separation groove 52. Light-emitting section side surface 512 is constituted by inner circumferential surface 521 of separation groove 52. Separation groove 52 extends from first surface 221 to the middle of second light reflecting layer 60 in semiconductor layer 22. Therefore, light-emitting section side surface 512 is constituted by the side surfaces of first light reflecting layer 40 and light generating layer 30, and a part of the side surface of second light reflecting layer 60. Inner circumferential surface 521 of separation groove 52 is an end surface in a direction perpendicular to the Z-axis direction. Therefore, it can be said that the side surfaces of first light reflecting layer 40 and light generating layer 30, and a part of the side surface of second light reflecting layer 60 are end surfaces in a direction perpendicular to the Z-axis direction.

[0029] The separation groove 52 defines the light emitting portion 51 relative to the semiconductor layer 22. Therefore, it can be said that the semiconductor layer 22 includes a frame portion 54 surrounding the light emitting portion 51. The frame portion 54 includes a frame surface 541 that configures a part of the first surface 221 of the semiconductor layer 22, and a frame side surface 542 that is configured by the outer circumferential surface 522 of the separation groove 52.

[0030] (Current confinement layer) As shown in FIG. 2, the light emitting section 51 may include a current confinement layer 53. The current confinement layer 53 is disposed between the first electrode 71 and the second light reflecting layer 60. The current confinement layer 53 is disposed between the first surface 221 of the semiconductor layer 22 and the second light reflecting layer 60. The current confinement layer 53 may be disposed between the light emitting section surface 511 and the light generating layer 30. In one example, the current confinement layer 53 is disposed in the first light reflecting layer 40. The current confinement layer 53 may be configured to constrict the current path of the light emitting section 51 in the Z-axis direction.

[0031] The current confinement layer 53 includes a passing layer 531 and an oxide layer 532. The passing layer 531 is made of a material containing Al. In one example, the passing layer 531 is made of an Al γ Ga (1-γ) The passing layer 531 may be made of a material containing As. The Al composition ratio γ may be 0.95 or more and 1.00 or less. The passing layer 531 may contain an impurity of the first conductivity type.

[0032] 5, the passage layer 531 is disposed in an inner region of the light-emitting section 51. In one example, the passage layer 531 is disposed in the center of the light-emitting section 51 in a planar view. In one example, the passage layer 531 may have a circular shape in a planar view. The diameter of the passage layer 531 may be 5 μm or more and 20 μm or less.

[0033] The oxide layer 532 is formed to surround the passage layer 531. In one example, the oxide layer 532 includes an oxide containing Al. The oxide containing Al is, for example, Al 2 O 3 (alumina). The oxide layer may contain Ga or As. The oxide layer 532 is disposed on the light-emitting section side surface 512 side of each light-emitting section 51 with respect to the passing layer 531. For example, the oxide layer 532 is made of Al γ Ga (1-γ) The oxide layer 532 is formed by oxidizing the periphery of the layer containing As. In one example, the oxide layer 532 can be formed by performing a heat treatment in water vapor.

[0034] (insulating film) 2, the surface-emitting laser device 10 may include an insulating film 73 that covers the first surface 221 of the semiconductor layer 22. The insulating film 73 may be, for example, SiO 2 , silicon oxide such as SiO, SiN (silicon nitride), SiON, ZrO 2 (zirconium oxide) or TiO (titanium oxide). In one example, the insulating film 73 is a SiN film.

[0035] The semiconductor layer 22 includes a separation groove 52 and a light emitting portion 51 surrounded by the separation groove 52. The insulating film 73 covers a light emitting portion surface 511 and a light emitting portion side surface 512 of the light emitting portion 51. The insulating film 73 also covers an outer circumferential surface 522 and a bottom surface 523 of the separation groove 52. The semiconductor layer 22 also includes a frame portion 54 that surrounds the light emitting portion 51 with the separation groove 52. The insulating film 73 covers a frame surface 541 of the frame portion 54.

[0036] The insulating film 73 includes an opening 731 that exposes a portion of the light-emitting portion surface 511 of the light-emitting portion 51. The opening 731 of the insulating film 73 is formed so as to surround the passing layer 531 in a planar view. The opening 731 may be formed in an annular shape in a planar view. In one example, the opening 731 may be annular. The insulating film 73 includes a covering portion 732 in a region located inward from the opening 731. The covering portion 732 is circular in a planar view. The covering portion 732 overlaps with the oxide layer 532 of the current confinement layer 53 in a planar view. The center of the opening 731 may coincide with the center of the covering portion 732, and may coincide with the center O1 of the light-emitting portion 51.

[0037] (1st electrode) 2, the first electrode 71 covers the insulating film 73. The first electrode 71 may include a plurality of electrode films. The first electrode 71 may be composed of a single electrode film. The first electrode 71 may include, for example, Au (gold), Ti (titanium), or Pt (platinum). In one example, the first electrode 71 is composed of a stack of a Ti layer, a Pt layer, and an Au layer.

[0038] The first electrode 71 includes a connection portion 711 in the opening 731 of the insulating film 73. The connection portion 711 is electrically connected to the first light reflecting layer 40. Therefore, the first electrode 71 is electrically connected to the first light reflecting layer 40.

[0039] The first electrode 71 includes an opening 712 that selectively exposes a portion of the covering portion 732 of the insulating film 73. The opening 712 of the first electrode 71 is provided at a position overlapping with the passage layer 531 of the current confinement layer 53 in a plan view. As shown in Fig. 5, the opening 712 of the first electrode 71 has a circular shape in a plan view. The shape of the opening 712 of the first electrode 71 in a plan view can be any shape, such as a polygonal shape or an elliptical shape.

[0040] The second electrode 72 covers the second substrate surface 212 of the substrate 21. The second electrode 72 forms an ohmic contact with the second substrate surface 212 of the substrate 21. The second electrode 72 may include a plurality of electrode films. The second electrode 72 may be composed of one electrode film. The first electrode 71 may include, for example, Ni (nickel), Au, Ge (germanium), Ti, In (indium), Zn (zinc), etc. In one example, the first electrode 71 is composed of a stack of an AuGe layer, a Ni layer, and an Au layer.

[0041] (Layer configuration of first light reflective layer and second light reflective layer) As shown in FIG. 5, the first light reflective layer 40 includes a plurality of first reflective layers 41 and a plurality of second reflective layers 42. The plurality of first light reflective layers 40 and the plurality of second reflective layers 42 are alternately arranged in the Z-axis direction. The first reflective layer 41 and the second reflective layer 42 are made of a material containing Al. In one example, the first reflective layer 41 and the second reflective layer 42 contain AlGaAs. The first reflective layer 41 and the second reflective layer 42 have different Al composition ratios. The first reflective layer 41 is made of Al having an Al composition ratio β1. β1 Ga (1-β1) The first reflective layer 41 may have an Al composition ratio β1 of 0.70 or more and 0.97 or less. The second reflective layer 42 may have an Al composition ratio β2 of β2 Ga (1-β2)The second reflective layer 42 includes As. The Al composition ratio β2 of the second reflective layer 42 may be greater than 0 and equal to or less than 0.2. The refractive index of the reflective layer including AlGaAs decreases as the Al composition ratio increases. Therefore, the first reflective layer 41 and the second reflective layer 42 have different refractive indices.

[0042] The second light reflective layer 60 includes a plurality of third reflective layers 61 and a plurality of fourth reflective layers 62. The plurality of third reflective layers 61 and the plurality of fourth reflective layers 62 are alternately arranged in the Z-axis direction. The third reflective layer 61 and the fourth reflective layer 62 are made of a material containing Al. In one example, the first reflective layer 41 and the second reflective layer 42 contain AlGaAs. The third reflective layer 61 and the fourth reflective layer 62 have different Al composition ratios. The third reflective layer 61 is made of Al having an Al composition ratio β3. β3 Ga (1-β3) The third reflective layer 61 may have an Al composition ratio β3 of 0.70 or more and 0.97 or less. The fourth reflective layer 62 may have an Al composition ratio β4 of β4 Ga (1-β4) The fourth reflective layer 62 includes As. The Al composition ratio β4 of the fourth reflective layer 62 may be greater than 0 and equal to or less than 0.2. The refractive index of a reflective layer including AlGaAs decreases as the Al composition ratio increases. Therefore, the third reflective layer 61 and the fourth reflective layer 62 have mutually different refractive indices.

[0043] The number of layers of the first reflective layer 41 and the second reflective layer 42 included in the first light reflective layer 40 may be different from the number of layers of the third reflective layer 61 and the fourth reflective layer 62 included in the second light reflective layer 60. In one example, the number of layers of the third reflective layer 61 and the fourth reflective layer 62 included in the second light reflective layer 60 is greater than the number of layers of the first reflective layer 41 and the second reflective layer 42 included in the first light reflective layer 40.

[0044] (1st area, 2nd area) As shown in FIG. 2 to FIG. 4 and FIG. 6, in the light emitting section 51, the first light reflecting layer 40 includes a first region 441 and a second region 442 inside the first region 441. The first region 441 is provided between the light emitting section side surface 512 of the light emitting section 51 and an end 731A of the opening 731 of the insulating film 73 in a plan view. The opening 712 of the first electrode 71 is provided at a position overlapping with the passing layer 531 of the current confinement layer 53 in a plan view. Therefore, it can be said that the first region 441 is provided between the light emitting section side surface 512 of the light emitting section 51 and the passing layer 531 of the current confinement layer 53 in a plan view. And, it can be said that the first region 441 is provided at a position overlapping with the oxide layer 532 of the current confinement layer 53 in a plan view.

[0045] The second region 442 is provided at the center of the light-emitting section 51 in a plan view. The second region 442 is surrounded by the first region 441 in a plan view. It can be said that the first region 441 is provided so as to surround the second region 442 in a plan view. It can be said that the second region 442 is provided at a position overlapping the opening 712 of the first electrode 71 in a plan view. It can be said that the second region 442 is provided at a position overlapping the passing layer 531 of the current confinement layer 53 in a plan view. The driving current supplied by the first electrode 71 is supplied to the active layer 31 of the light generation layer 30 through the passing layer 531 of the current confinement layer 53. Therefore, it can be said that the second region 442 is a region through which the driving current passes. The light generated in the light generation layer 30 passes through the opening 712 of the first electrode 71 and is emitted to the outside. Therefore, it can be said that the second region 442 is a region through which light passes. The second region 442 includes a laminated structure of the first reflective layer 41 and the second reflective layer 42 of the first light reflective layer 40 .

[0046] The first region 441 is a region containing Al and Zn. In one example, the first region 441 is a diffusion region in which Zn is diffused in the first light reflecting layer 40 containing Al. On the other hand, the second region 442 is a region that does not substantially contain Zn. "Substantially not containing Zn" means that Zn is not intentionally contained in the target object.

[0047] The first light reflecting layer 40 contains C as a first conductive type impurity. The first region 441 contains Zn. Therefore, the first region 441 formed in the first light reflecting layer 40 is a region containing C and Zn. Zn is one of p-type impurities. In one example, the first region 441 may be a region containing C and Zn as carriers. In one example, the concentration of Zn in the first region 441 is 1.0×10 20 cm -3 or less. It can be said that the carrier concentration of the first region 441 is different from the carrier concentration of the second region 442. When the first light reflecting layer 40 is a p-type semiconductor layer, it can be said that the first region 441 is a region having a higher impurity concentration than the second region 442.

[0048] As shown in FIG. 4, the first region 441 is annular in plan view. As shown in FIG. 3, the first region 441 is provided from the light-emitting portion side surface 512 of the light-emitting portion 51 toward the center of the light-emitting portion 51. In a plan view, the center of the light-emitting portion 51 is also the center of the opening 731 of the insulating film 73. Therefore, it can be said that the first region 441 is provided from the light-emitting portion side surface 512 toward the center of the opening 731 of the insulating film 73 in a plan view. The inner end 441A of the first region 441 is a boundary portion between the first region 441 and the second region 442. The inner end 441A of the first region 441 may be an arc shape extending between the light-emitting portion surface 511 of the light-emitting portion 51 and the light-emitting portion side surface 512 of the light-emitting portion 51. In a plan view, the inner end 441A of the first region 441 is located closer to the light-emitting portion side surface 512 of the light-emitting portion 51 than the end 712A of the opening 712 of the first electrode 71. The inner end 441 A of the first region 441 may be formed so as to approach the light emitting portion side surface 512 of the light emitting portion 51 from the light emitting portion surface 511 of the light emitting portion 51 toward the oxide layer 532 of the current confinement layer 53 .

[0049] The first region 441 includes a plurality of first layers 461 and a plurality of second layers 462. The plurality of first layers 461 and the plurality of second layers 462 are alternately arranged in the Z-axis direction. The first layer 461 is disposed in a direction perpendicular to the Z-axis direction with respect to the first reflective layer 41. The first layer 461 is formed by adding Zn to the first reflective layer 41. The first layer 461 is formed in a ring shape surrounding the first reflective layer 41. The second layer 462 is disposed in a direction perpendicular to the Z-axis direction with respect to the second reflective layer 42. The second layer 462 is formed by adding Zn to the second reflective layer 42. The second layer 462 is formed in a ring shape surrounding the second reflective layer 42.

[0050] As shown in FIG. 6, the oxide layer 532 of the current confinement layer 53 may extend further into the light emitting section 51 than the end 731A of the opening 731 of the insulating film 73 on the outer side in a plan view. The oxide layer 532 of the current confinement layer 53 may extend further into the light emitting section 51 than the end 712A of the opening 712 of the first electrode 71 in a plan view. The distance L1 between the inner end 441A of the first region 441 and the opening 731 of the insulating film 73 is longer than the distance L2 between the end 731A of the opening 731 of the insulating film 73 and the inner end 532A of the oxide layer 532. The distance L1 between the inner end 441A of the first region 441 and the opening 731 of the insulating film 73 may be equal to the distance L2 between the end 731A of the opening 731 of the insulating film 73 and the inner end 532A of the oxide layer 532 of the current confinement layer 53. In addition, the distance L1 between the inner end 441A of the first region 441 and the end 731A of the opening 731 of the insulating film 73 may be shorter than the distance L2 between the end 731A of the opening 731 of the insulating film 73 and the inner end 532A of the oxide layer 532 of the current confinement layer 53.

[0051] (Oxide layer of the first light reflecting layer) As shown in FIG. 3, in the light emitting section 51, the first light reflecting layer 40 includes a first reflecting layer 41A between the lower end 441B of the first region 441 and the current narrowing layer 53. It is preferable that the light emitting section 51 does not include a first reflecting layer 41A between the lower end 441B of the first region 441 and the current narrowing layer 53. The first reflecting layer 41A is exposed from the light emitting section side surface 512 between the first region 441 and the current narrowing layer 53. The first reflecting layer 41A includes an oxide layer 411 exposed from the light emitting section side surface 512. The oxide layer 411 may include an Al oxide. The first reflecting layer 41A is a semiconductor layer having a high Al composition ratio. The oxide layer 411 is formed by oxidation of the first reflecting layer 41A exposed from the light emitting section side surface 512.

[0052] (Oxide layer of second light reflective layer) As shown in FIG. 3, in light-emitting section 51, second light reflecting layer 60 includes one or more third reflecting layers 61A disposed between light generating layer 30 and bottom surface 523 of separation groove 52. Third reflecting layer 61A is exposed from light-emitting section side surface 512. Third reflecting layer 61A includes oxide layer 611 exposed from light-emitting section side surface 512. Oxide layer 611 may include Al oxide. Third reflecting layer 61A is a semiconductor layer having a high Al composition ratio. Oxide layer 611 is formed by oxidation of third reflecting layer 61A exposed from light-emitting section side surface 512.

[0053] (First area of ​​the frame) In the frame portion 54, the first light reflecting layer 40 may include a first region 441. The first region 441 of the frame portion 54 may be formed in a ring shape surrounding the light emitting portion 51 in a plan view. The first region 441 of the frame portion 54 is formed from the frame surface 541 to the frame side surface 542. The first region 441 of the frame portion 54 is a region containing Al and Zn, similar to the first region 441 of the light emitting portion 51. The first region 441 of the frame portion 54 may be omitted.

[0054] In the frame portion 54, the first light reflective layer 40 includes a first reflective layer 41A between a lower end 441B of the first region 441 and the oxide layer 532 of the current confinement layer 53. The first reflective layer 41A is exposed from a frame side surface 542. The first reflective layer 41A includes an oxide layer 411 exposed to the frame side surface 542.

[0055] In frame portion 54, second light reflecting layer 60 includes one or more third reflecting layers 61A disposed between light generating layer 30 and bottom surface 523 of separation groove 52. Third reflecting layer 61A is exposed from outer circumferential surface 522 of separation groove 52. Third reflecting layer 61A includes an oxide layer 611 exposed to light emitting portion side surface 512.

[0056] (Al composition, impurity concentration) The first light reflecting layer 40 is composed of a plurality of first reflecting layers 41 and a plurality of second reflecting layers 42 arranged alternately in the Z-axis direction. The first reflecting layers 41 and the second reflecting layers 42 are formed by, for example, a metal organic chemical vapor deposition (MOCVD) method.

[0057] The first light reflective layer 40 includes a first region 441 containing Zn and a second region 442 surrounded by the first region 441. The first layer 461 containing Zn has an Al composition ratio different from that of the first reflective layer 41 not containing Zn. Similarly, the second layer 462 containing Zn has an Al composition ratio different from that of the second reflective layer 42 not containing Zn.

[0058] 9 shows a part of the first light reflecting layer 40, the first reflecting layer 41 and the second reflecting layer 42 included in the second region 442. The first reflecting layer 41 and the second reflecting layer 42 have a configuration in which the Al composition ratio does not change in the Z-axis direction. The interface 822 between the first reflecting layer 41 and the second reflecting layer 42 is clear and distinct.

[0059] Fig. 8 shows a part of the first light reflecting layer 40, including a boundary portion 81 between the first region 441 and the second region 442. The density of the dot hatching in Fig. 8 indicates the magnitude of the Al composition ratio.

[0060] The first light reflective layer 40 includes a first region 441 and a second region 442. The first region 441 includes a first layer 461 and a second layer 462, and the second region 442 includes a first reflective layer 41 and a second reflective layer 42.

[0061] The first reflective layer 41 and the second reflective layer 42 in the second region 442 have a uniform Al composition ratio in the Z-axis direction. The interface 822 between the first reflective layer 41 and the second reflective layer 42 is clear and distinct. It can be said that the interface 822 exists between the first reflective layer 41 and the second reflective layer 42 in the second region 442 of the first light reflective layer 40.

[0062] The first layer 461 and the second layer 462 of the first region 441 contain Zn. The first region 441 has a different composition from the first reflective layer 41 and the second reflective layer 42 due to the diffused Zn. In the plurality of first layers 461 and the plurality of second layers 462, a phenomenon occurs in which the constituent atoms are mixed between the first layer 461 and the second layer 462 due to the diffused Zn. Due to this phenomenon, the Al composition ratio of the first layer 461 decreases, and the Al composition ratio of the second layer 462 increases. Therefore, the Al composition ratio of the first layer 461 becomes lower than the Al composition ratio of the first reflective layer 41. Moreover, the Al composition ratio of the second layer 462 becomes higher than the composition ratio of the second reflective layer 42. Therefore, it can be said that the Al composition ratio of the first region 441 is lower than the Al composition ratio of the first reflective layer 41. Moreover, it can be said that the Al composition ratio of the first region 441 is higher than the Al composition ratio of the second reflective layer 42.

[0063] The Al composition ratio of the first layer 461 may be higher than the Al composition ratio of the second layer 462. The Al composition ratio of the first layer 461 may be equal to the Al composition ratio of the second layer 462. Furthermore, the first layer 461 and the second layer 462 of the first region 441 may have a composition gradient. The composition gradient means that the Al composition ratio of the first layer 461 and the second layer 462 containing AlGaAs gradually increases or decreases in the Z-axis direction.

[0064] The first layer 461 included in the first region 441 has an Al composition ratio that gradually decreases toward the second layer 462 in the Z-axis direction. The second layer 462 included in the first region 441 has an Al composition ratio that gradually increases toward the first layer 461 in the Z-axis direction. For this reason, the interface 821 between the first layer 461 and the second layer 462 is blurred more than the interface 822 between the first reflective layer 41 and the second reflective layer 42. It can be said that the interface 821 between the first layer 461 and the second layer 462 is unclear. In the first region 441, the first layer 461 and the second layer 462 adjacent to each other in the Z-axis direction are partially mixed together, and there are cases where the interface 821 does not exist in parts. It can be said that the interface 821 between the first layer 461 and the second layer 462 does not exist in some parts in the first region 441.

[0065] The Al composition ratio of the first layer 461 is lower than that of the first reflective layer 41. The Al composition ratio of the second layer 462 is higher than that of the second reflective layer 42. Therefore, the difference between the Al composition ratio of the first layer 461 and that of the second layer 462 is smaller than the difference between the Al composition ratio of the first reflective layer 41 and that of the second reflective layer 42. In addition, the first layer 461 and the second layer 462 having a composition gradient have a small difference in the Al composition ratio between the first layer 461 and the second layer 462. The composition gradient reduces the barrier in the first layer 461 and the second layer 462 when a voltage is applied. As a result, the electrical resistance of the first layer 461 and the second layer 462 in the first region 441 is lower than the electrical resistance of the first reflective layer 41 and the second reflective layer 42 in the second region 442 that does not have a composition gradient.

[0066] An interface 822 between the first reflective layer 41 and the second reflective layer 42 included in the second region 442 is clear. The refractive index of the first reflective layer 41 and the refractive index of the second reflective layer 42 are different from each other. On the other hand, an interface 821 between the first layer 461 and the second layer 462 included in the first region 441 is blurred more than an interface 822 between the first reflective layer 41 and the second reflective layer 42 included in the second region 442.

[0067] The first reflective layer 41 and the second reflective layer 42 in the second region 442 may have a composition gradient. The first reflective layer 41 and the second reflective layer 42 are formed by MOCVD. The composition gradient of the first reflective layer 41 and the second reflective layer 42 is obtained by adjusting the flow rate of the metalorganic gas when the first reflective layer 41 and the second reflective layer 42 are formed by MOCVD. Therefore, the second region 442 including the first reflective layer 41 and the second reflective layer 42 having a composition gradient has a low electric resistance. Even when the first reflective layer 41 and the second reflective layer 42 have a composition gradient, the Al composition ratio of the first layer 461 containing Zn is lower than the Al composition ratio of the first reflective layer 41, and the Al composition ratio of the second layer 462 is higher than the Al composition ratio of the second reflective layer 42. Therefore, the Al composition ratio of the first region 441 is lower than the Al composition ratio of the first reflective layer 41.

[0068] Second light reflecting layer 60 may or may not have a composition gradient. First cladding layer 32 and second cladding layer 33 of light generating layer 30 may or may not have a composition gradient. The composition gradients of second light reflecting layer 60, first cladding layer 32, and second cladding layer 33 are obtained in the same manner as the composition gradients of first light reflecting layer 40 and second light reflecting layer 60. For example, third reflecting layer 61 and fourth reflecting layer 62 of second light reflecting layer 60 are formed by MOCVD. The composition gradients of third reflecting layer 61 and fourth reflecting layer 62 are obtained by adjusting the flow rate of an organic metal gas when forming third reflecting layer 61 and fourth reflecting layer 62 by MOCVD.

[0069] (Method of manufacturing a surface-emitting laser device) Next, an example of a method for manufacturing the surface emitting laser device 10 shown in FIGS. 1 to 5 will be described. Figures 10 to 15 are schematic cross-sectional views showing exemplary manufacturing steps of the surface-emitting laser device 10. Figures 10 to 15 correspond to the cross-sectional structure of the surface-emitting laser device 10 shown in Figure 2. For ease of understanding, in Figures 10 to 15, the same reference numerals as in Figure 2 are used for components that are the same as the final components of the surface-emitting laser device 10.

[0070] As shown in FIG. 10, the method for manufacturing the surface-emitting laser device 10 includes forming a semiconductor layer 22 on a substrate 21. First, a substrate 21 is prepared. The substrate 21 may be in a wafer state. The substrate 21 may be in a wafer state for forming a plurality of surface-emitting laser devices 10.

[0071] The substrate 21 includes a first substrate surface 211 and a second substrate surface 212 that face in opposite directions in the Z-axis direction. Semiconductor layer 22 is formed on first substrate surface 211 of substrate 21. Semiconductor layer 22 includes second light reflecting layer 60, light generating layer 30, and first light reflecting layer 40. Second light reflecting layer 60, light generating layer 30, and first light reflecting layer 40 are sequentially stacked on substrate 21 to form semiconductor layer 22. Second light reflecting layer 60, light generating layer 30, and first light reflecting layer 40 are formed by MOCVD. Semiconductor layer 22 includes current confinement layer 53. Current confinement layer 53 is a high Al composition layer having a high Al composition ratio.

[0072] 11, the method for manufacturing the surface-emitting laser device 10 includes forming the first region 441. The first region 441 can be formed by, for example, a diffusion method. Note that the first region 441 may be formed by a method other than the diffusion method.

[0073] First, the supply source 90 is disposed on the first light reflecting layer 40. The supply source 90 has an annular shape in a plan view. The supply source 90 is disposed so as to surround the portion forming the light emitting section 51 shown in FIG. 1. In one example, the supply source 90 is made of ZnO. 2(zinc oxide) can be used. The supply source 90 can be formed by, for example, a sputtering method or a plasma CVD method. Next, Zn is diffused from the supply source 90 into the first light reflecting layer 40 by a diffusion method to form a diffusion region 91. The diffusion region 91 is formed so as not to reach the current confinement layer 53, which is a high Al composition layer. Note that it is only necessary that the current confinement layer 53 is exposed at the inner circumferential surface 521 of the separation groove 52, and the diffusion region 91 may reach the current confinement layer 53.

[0074] As shown in FIG. 12, the method for manufacturing the surface-emitting laser device 10 includes forming a separation groove 52 in the semiconductor layer 22. The separation groove 52 is formed deeper than the light generating layer 30. The separation groove 52 is formed along the annular diffusion region 91 so as to remove a part of the diffusion region 91. The separation groove 52 is formed by selectively removing the first light reflecting layer 40, the light generating layer 30, and the second light reflecting layer 60, for example, by dry etching. The separation groove 52 forms a mesa portion that becomes the light emitting section 51. The light emitting section 51 includes a light emitting section surface 511 and a light emitting section side surface 512. The separation groove 52 is formed so that a part of the diffusion region 91 remains in the light emitting section 51. The remaining part of the diffusion region 91 becomes the first region 441. In addition, the size (radial width) of the diffusion region 91 in a plan view can be appropriately set to form the first region 441 in the frame section 54 surrounding the light emitting section 51.

[0075] 13, the method for manufacturing the surface-emitting laser device 10 includes forming the current confinement layer 53. The current confinement layer 53 is formed by a heat treatment in water vapor. 14, the method for manufacturing the surface-emitting laser device 10 includes forming an insulating film 73. The insulating film 73 is formed by, for example, a CVD method. The insulating film 73 is formed so as to cover the surfaces of the first light reflecting layer 40, the light generating layer 30, and the second light reflecting layer 60.

[0076] The manufacturing method of the surface-emitting laser device 10 includes forming an opening 731 in the insulating film 73. The opening 731 in the insulating film 73 is formed by selectively removing a portion covering the light-emitting surface 511 by, for example, an etching method (for example, wet etching). A part of the light-emitting surface 511 is exposed from the opening 731 in the insulating film 73.

[0077] 15, the method for manufacturing the surface-emitting laser device 10 includes forming a first electrode 71. The first electrode 71 is formed by a deposition method, a sputtering method, or the like. The manufacturing method of the surface-emitting laser device 10 includes forming an opening 712 in the first electrode 71. The opening 712 is formed by selectively removing a portion of the first electrode 71 that covers the light-emitting portion surface 511 of the light-emitting portion 51, for example, by an etching method (for example, wet etching).

[0078] The manufacturing method of the surface-emitting laser device 10 includes forming the second electrode 72. The second electrode 72 is formed on the second substrate surface 212 of the substrate 21. The second electrode 72 is formed by a deposition method, a sputtering method, or the like. The second electrode 72 may be formed prior to the first electrode 71. Also, the second electrode 72 may be formed prior to a step of forming an opening in the first electrode 71.

[0079] (Operation of the embodiment) Next, the operation of the surface emitting laser device 10 will be described. First, a surface-emitting laser device 10X of the comparative example will be described. Note that, in the surface-emitting laser device 10X of the comparative example, the same members as those in the surface-emitting laser device 10 described above will be described using the same reference numerals.

[0080] 7 shows a schematic cross section of a surface-emitting laser device 10X of a comparative example, which corresponds to the schematic cross section of the surface-emitting laser device 10 of the embodiment shown in FIG. The surface-emitting laser device 10X of the comparative example is different from the surface-emitting laser device 10 of the embodiment in the configuration of the first light reflecting layer 40X. The first light reflecting layer 40X of the comparative example does not contain Zn, that is, does not contain the first region 441 shown in FIGS.

[0081] In the surface-emitting laser device 10X of the comparative example, the first light reflective layer 40X includes a plurality of first reflective layers 41. The plurality of first reflective layers 41 are exposed to the light-emitting section side surface 512 of the light-emitting section 51. The plurality of first reflective layers 41 each include an oxide layer 411 exposed to the light-emitting section side surface 512 of the light-emitting section 51. The oxide layer 411 is formed by oxidizing the first reflective layer 41 exposed from the light-emitting section side surface 512 of the light-emitting section 51. The oxide layer 411 of the first reflective layer 41 is formed simultaneously with the oxide layer 532 of the current confinement layer 53.

[0082] The first reflective layer 41 having a high Al concentration is easily oxidized, and volume shrinkage occurs due to oxidation. Therefore, the thickness T2 of the oxide layer 411 in the Z-axis direction is smaller than the thickness T1 of the first reflective layer 41 in the second region 442. Therefore, the first light reflective layer 40X is distorted at the boundary portion 83X between the first reflective layer 41 and the oxide layer 411. The stress due to this distortion affects the life of the light emitting unit 51.

[0083] As shown in FIG. 3, the first light reflecting layer 40 of the surface-emitting laser device 10 of the embodiment includes a first region 441 provided between the light-emitting section side surface 512 and the end of the opening 731 of the insulating film 73 in a plan view. The first region 441 includes Al and Zn, and has a lower Al composition ratio than the first reflecting layer 41. Therefore, in the surface-emitting laser device 10 of the embodiment, the number of first reflecting layers 41 exposed to the light-emitting section side surface 512 of the light-emitting section 51 is smaller than that of the surface-emitting laser device 10X of the comparative example. Therefore, it is possible to suppress the inclusion of the oxide layer 411 in the multiple first reflecting layers 41 of the first light reflecting layer 40. Therefore, it is possible to reduce the occurrence of distortion and stress in the first light reflecting layer 40.

[0084] The first region 441 contains Al and Zn. The Zn contained in the first region 441 is an impurity of the same conductivity type as C in the first light reflecting layer 40 containing C as an impurity. Therefore, the first region 441 containing C and Zn is a region with lower electrical resistance than the second region 442. The first region 441 is provided between the light emitting section side surface 512 and the end of the opening 731 of the insulating film 73 in a plan view. The opening 731 of the insulating film 73 is provided with the connection portion 711 of the first electrode 71. Therefore, by arranging the first region 441 with a low resistance value outside the connection portion 711 of the first electrode 71, it is possible to suppress the driving current supplied from the first electrode 71 from flowing into the first region 441 with a low resistance value.

[0085] The current confinement layer 53 includes a passing layer 531 configured to allow a current to pass therethrough, and an oxide layer 532 surrounding the passing layer 531. The oxide layer 532 is an insulator, and the current confinement layer 53 confines the driving current supplied from the first electrode 71. The inner end 441A of the oxide layer 532 extends further inward than the end 731A of the opening 731 of the insulating film 73. The driving current supplied from the connection portion 711 of the first electrode 71 to the first light reflecting layer 40 flows toward the inside of the light emitting section 51 from the end 731A of the opening 731 of the insulating film 73 in which the connection portion 711 of the first electrode 71 is disposed. Therefore, the driving current supplied from the first electrode 71 can be prevented from flowing into the first region 441 having a low resistance value.

[0086] (Effects of the embodiment) As described above, according to this embodiment, the following effects are achieved. (1) The surface-emitting laser device 10 includes a light generating layer 30, a first light reflecting layer 40, a second light reflecting layer 60, an insulating film 73, a first electrode 71, a second electrode 72, and a current narrowing layer 53. The first light reflecting layer 40 and the second light reflecting layer 60 are made of a material containing Al, and are arranged to sandwich the light generating layer 30 in the Z-axis direction of the light generating layer 30. The insulating film 73 is provided on the first surface 401 of the first light reflecting layer 40, and includes an opening that exposes a part of the first surface 401 of the first light reflecting layer 40. The first electrode 71 is provided across the insulating film 73 and the first light reflecting layer 40, and is electrically connected to the first light reflecting layer 40. The second electrode 72 is electrically connected to the second light reflecting layer. The current narrowing layer 53 is arranged between the second light reflecting layer 60 and the second electrode 72. The current confinement layer 53 includes a passing layer 531 configured to allow a current to pass therethrough, and an oxide layer 532 surrounding the passing layer 531 .

[0087] The first light reflecting layer 40 is made of a material containing Al and includes a plurality of first reflecting layers 41 and a plurality of second reflecting layers 42 arranged alternately in the Z-axis direction. The Al composition ratio β1 of the first reflecting layer 41 is higher than the Al composition ratio β2 of the second reflecting layer 42. The laminated structure of the first reflecting layer 41 and the second reflecting layer 42 is provided at a position overlapping the passing layer 531. The first light reflecting layer 40 includes a light emitting section side surface 512 which is an end surface in a direction perpendicular to the Z-axis direction, and a first region 441 provided between the light emitting section side surface 512 and an end of the opening 731 of the insulating film 73 in a plan view. The first region 441 includes Al and Zn, and has a lower Al composition ratio than the first reflecting layer 41.

[0088] The surface-emitting laser device 10 of the present embodiment can prevent the oxide layer 411 from being included in the multiple first reflective layers 41 of the first light reflective layer 40. This can reduce the occurrence of distortion and stress in the first light reflective layer 40. This can prevent the life of the surface-emitting laser device 10 from being shortened.

[0089] (2) The first region 441 contains Al and Zn. The Zn contained in the first region 441 is an impurity of the same conductivity type as C in the first light reflecting layer 40 containing C as an impurity. Therefore, the first region 441 containing C and Zn is a region with lower electrical resistance than the second region 442. The first region 441 is provided between the light emitting section side surface 512 and the end of the opening 731 of the insulating film 73 in a plan view. The opening 731 of the insulating film 73 is provided with the connection portion 711 of the first electrode 71. Therefore, by arranging the first region 441 with a low resistance value outside the connection portion 711 of the first electrode 71, it is possible to suppress the drive current supplied from the first electrode 71 from flowing into the first region 441 with a low resistance value. Therefore, it is possible to suppress a decrease in the efficiency of the generated light with respect to the drive current supplied from the first electrode 71.

[0090] (3) The current confinement layer 53 includes a passing layer 531 configured to allow a current to pass therethrough, and an oxide layer 532 surrounding the passing layer 531. The oxide layer 532 is an insulator, and the current confinement layer 53 confines the driving current supplied from the first electrode 71. The inner end 441A of the oxide layer 532 extends further inward than the end 731A of the opening 731 of the insulating film 73. The driving current supplied from the connection portion 711 of the first electrode 71 to the first light reflecting layer 40 flows toward the inside of the light emitting portion 51 from the end 731A of the opening 731 of the insulating film 73 in which the connection portion 711 of the first electrode 71 is disposed. Therefore, the driving current supplied from the first electrode 71 can be prevented from flowing into the first region 441 having a low resistance value. Therefore, the efficiency decrease of the generated light can be suppressed with respect to the driving current supplied from the first electrode 71.

[0091] (Example of change) The above embodiment can be modified, for example, as follows. The above embodiment and the following modified examples can be combined with each other as long as no technical contradiction occurs. In the following modified examples, the same reference numerals as in the above embodiment are used for the parts common to the above embodiment, and the description thereof will be omitted.

[0092] The number of light emitting sections included in the surface emitting laser device may be changed as appropriate. As shown in FIG. 16, a surface-emitting laser device 110 including one light-emitting section 51 may be used.

[0093] The first light reflecting layer 40 may contain p-type impurities such as Mg (magnesium), and the second light reflecting layer 60 may contain n-type impurities such as Te (tellurium). The first conductivity type and the second conductivity type may be changed as appropriate. The first conductivity type may be n-type, and the second conductivity type may be p-type.

[0094] The first light reflecting layer 40 contains, for example, Si as an n-type impurity. The second light reflecting layer 60 contains, for example, C as a p-type impurity. The first region 441 contains Zn. Zn is a p-type impurity. In the first light reflecting layer 40 containing AlGaAs, Zn and Si act as different carriers. Therefore, it can be said that the first region 441 of the first light reflecting layer 40 has a different carrier concentration from the second region 442. It can be said that the carrier concentration of the first region 441 is lower than the carrier concentration of the second region. The first region 441 is provided between the light emitting portion side surface 512 of the light emitting portion 51 and the end 731A of the opening 731 of the insulating film 73. Therefore, it is possible to reduce the influence of the first region 441 containing Zn on the current path in the second region 442 containing Si.

[0095] The term "on" as used in this disclosure includes both the meanings of "on" and "above" unless the context clearly indicates otherwise. Thus, the phrase "a first layer is formed on a second layer" is intended to mean that in some embodiments, the first layer may be disposed directly on the second layer in contact with the second layer, while in other embodiments, the first layer may be disposed above the second layer without contacting the second layer. That is, the term "on" does not exclude a structure in which another layer is formed between the first layer and the second layer.

[0096] The Z-axis direction used in the present disclosure does not necessarily have to be a vertical direction, nor does it have to completely coincide with the vertical direction. Therefore, various structures according to the present disclosure (for example, the structure shown in FIG. 1) are not limited to the "up" and "down" of the Z-axis direction described in this specification being "up" and "down" of the vertical direction. For example, the X-axis direction may be a vertical direction, or the Y-axis direction may be a vertical direction.

[0097] (Additional Note) The technical ideas that can be understood from the present disclosure are described below. Note that, for the purpose of aiding understanding, not for the purpose of limitation, the components described in the appendices are given the reference symbols of the corresponding components in the embodiments. The reference symbols are shown as examples for the purpose of aiding understanding, and the components described in each appendix should not be limited to the components indicated by the reference symbols.

[0098] (Appendix 1) a light generating layer (30); a first light reflecting layer (40) and a second light reflecting layer (60) made of a material containing Al and disposed on either side of the light generating layer (30) in a thickness direction (Z) of the light generating layer (30); an insulating film (73) provided on a first surface (401) of the first light reflecting layer (40), the insulating film having an opening (731) exposing a portion of the first surface (401) of the first light reflecting layer (40); a first electrode (71) provided across the insulating film (73) and the first light reflecting layer (40) and electrically connected to the first light reflecting layer (40); a second electrode (72) electrically connected to the second light reflecting layer (60); a current confinement layer (53) including a passing layer (531) arranged between the second light reflecting layer (60) and the second electrode (72) and configured to allow a current to pass therethrough, and an oxide layer (532) surrounding the passing layer (531); Including, the first light reflecting layer (40) is made of a material containing Al and includes a plurality of first reflecting layers (41) and a plurality of second reflecting layers (42) alternately arranged in the thickness direction (Z), the Al composition ratio of the first reflecting layers (41) is higher than the Al composition ratio of the second reflecting layers (42), the laminated structure of the first reflective layer (41) and the second reflective layer (42) is provided at a position overlapping the passing layer (531); The first light reflecting layer (40) is A side surface (512) which is an end surface in a direction perpendicular to the thickness direction (Z); a first region (441) provided between the side surface (512) and an edge (731A) of the opening (731) of the insulating film (73) as viewed in the thickness direction (Z), the first region (441) containing Al and Zn and having a lower Al composition ratio than the first reflective layer (41); A surface emitting laser device comprising:

[0099] (Appendix 2) an inner end of the first region (441) is located closer to the side surface (512) of the first light reflecting layer (40) than an end (731A) of the opening (731) of the insulating film (73) is when viewed from the thickness direction (Z); 2. A surface-emitting laser device as described in claim 1.

[0100] (Appendix 3) An inner end (441A) of the first region (441) approaches the side surface (512) of the first light reflecting layer (40) toward the oxide layer (532). 3. A surface-emitting laser device according to claim 1 or 2.

[0101] (Appendix 4) the oxide layer (532) extends further inward than the edge (731A) of the opening (731) of the insulating film (73); 4. A surface-emitting laser device according to claim 1.

[0102] (Appendix 5) a distance (L1) between an inner end (441A) of the first region (441) and the opening (731) of the insulating film (73) is longer than a distance (L2) between the opening of the insulating film (73) and an inner end (532A) of the oxide layer (532); 5. A surface-emitting laser device according to claim 1.

[0103] (Appendix 6) a distance (L1) between an inner end (441A) of the first region (441) and the opening (731) of the insulating film (73) is shorter than a distance (L2) between the opening of the insulating film (73) and an inner end (532A) of the oxide layer (532); 6. A surface-emitting laser device according to claim 1,

[0104] (Appendix 7) a distance (L1) between an inner end (441A) of the first region (441) and the opening (731) of the insulating film (73) is equal to a distance (L2) between the opening (731) of the insulating film (73) and an inner end (532A) of the oxide layer (532); 7. A surface-emitting laser device according to claim 1.

[0105] (Appendix 8) The first region (441) has a laminated structure of a first layer (461) having a lower concentration than the first reflective layer (41) and a second layer (462) having a higher concentration than the second reflective layer (42). 8. A surface-emitting laser device according to claim 1.

[0106] (Appendix 9) the first light reflecting layer (40) includes a second region (442) through which light from the light generating layer (30) passes; the carrier concentration of the first region (441) is different from the carrier concentration of the second region (442); 9. A surface-emitting laser device according to any one of claims 1 to 8.

[0107] (Appendix 10) the interface (821) between the layers in the first region (441) is blurred more than the interface (822) between the layers in the second region (442); 10. The surface-emitting laser device according to claim 9.

[0108] (Appendix 11) the second light reflecting layer (60) includes a plurality of third reflecting layers (61) and a plurality of fourth reflecting layers (62) alternately arranged from the first light reflecting layer (40) toward the second electrode (72), the third reflective layers (61) and the fourth reflective layers (62) are made of a material containing Al; 11. A surface-emitting laser device according to claim 1.

[0109] (Appendix 12) The Al composition ratio of the third reflective layers (61) is higher than the Al composition ratio of the fourth reflective layers (62); 12. The surface-emitting laser device according to claim 11.

[0110] (Appendix 13) The Al composition ratio in the first region (441) is lower than the Al composition ratio in the first reflective layer (41) and is higher than the Al composition ratio in the second reflective layer (42). 13. A surface-emitting laser device according to any one of claims 1 to 12.

[0111] (Appendix 14) The first electrode (71) has a circular opening that is smaller than the opening (731) of the insulating film (73) when viewed in the thickness direction (Z). 14. A surface-emitting laser device according to any one of claims 1 to 13.

[0112] (Appendix 15) the insulating film (73) includes a covering portion (732) in a region of the insulating film (73) located inwardly of the opening (731); The opening (712) of the first electrode (71) is formed so as to expose a part of the covering portion (732). 15. The surface-emitting laser device according to claim 14.

[0113] (Appendix 16) The first light reflecting layer (40) includes a DBR layer of a first conductivity type, The second light reflecting layer (60) includes a DBR layer of a second conductivity type different from the first conductivity type. 16. A surface-emitting laser device according to any one of claims 1 to 15.

[0114] (Appendix 17) 17. The surface-emitting laser device of claim 16, wherein the first conductivity type is p-type and the second conductivity type is n-type.

[0115] (Appendix 18) 17. The surface-emitting laser device of claim 16, wherein the first conductivity type is n-type and the second conductivity type is p-type.

[0116] (Appendix 19) a light-emitting portion (51) that penetrates the first light-reflecting layer (40) and the light-generating layer (30) in the thickness direction (Z) to reach the second light-reflecting layer (60) and is partitioned by an annular separation groove (52) when viewed in the thickness direction (Z); the side surface (512) of the first light reflecting layer (40) is a side surface (512) of the light emitting portion (51); 19. A surface-emitting laser device according to any one of claims 1 to 18.

[0117] (Appendix 20) The separation groove (52) includes an inner circumferential surface (521) and an outer circumferential surface (522), The side surfaces of the first light reflecting layer (40) are the inner peripheral surface (521) and the outer peripheral surface (522). 20. The surface-emitting laser device of claim 19.

[0118] (Appendix 21) A plurality of the light emitting units (51), 21. The surface-emitting laser device according to claim 19 or 20.

[0119] (Appendix 22) The light emitting portion (51) has a circular shape when viewed from the thickness direction (Z), The passage layer (531) of the current confinement layer (53) is disposed at the center when viewed from the thickness direction (Z). 22. The surface-emitting laser device according to claim 19,

[0120] (Appendix 23) The light generating layer (30) includes an active layer, and a first cladding layer (32) and a second cladding layer (33) disposed on either side of the active layer. 23. The surface-emitting laser device according to claim 1,

[0121] (Appendix 24) A substrate (21) including a first substrate surface (211) and a second substrate surface (212) facing in opposite directions; the second light reflecting layer (60), the light generating layer (30), and the first light reflecting layer (40) are disposed on the first substrate surface (211); 24. The surface-emitting laser device according to claim 1,

[0122] (Appendix 25) The second electrode (72) is provided on the second substrate surface (212). 25. The surface-emitting laser device according to claim 24.

[0123] (Appendix 26) Sequentially forming a second light reflective layer (60), a light generating layer (30), and a first light reflective layer (40) on a semiconductor substrate; disposing a source containing Zn on the second light-reflecting layer (60); diffusing Zn from the supply source into the first light reflecting layer (40) by heat treatment to form an annular diffusion region as viewed from the thickness direction (Z) so that Zn does not reach a high Al composition layer included in the first light reflecting layer (40) in the thickness direction (Z); removing said source; removing a portion of the diffusion region along the annular diffusion region to form a light emitting portion (51) in which the diffusion region is exposed on a side surface (512) of the light emitting portion (51); oxidizing the high Al composition layer from a side surface (512) of the light emitting portion (51) by oxidation treatment to form a current confinement layer (53) including an oxide layer (532); A method for manufacturing a surface emitting laser device comprising the steps of:

[0124] (Appendix 27) a light generating layer (30); a first light reflecting layer (40) and a second light reflecting layer (60) made of a material containing Al and disposed on either side of the light generating layer (30) in a thickness direction (Z) of the light generating layer (30); an insulating film (73) provided on a first surface of the first light reflecting layer (40) and having an opening exposing a portion of the first surface of the first light reflecting layer (40); a first electrode (71) provided across the insulating film (73) and the first light reflecting layer (40) and electrically connected to the first light reflecting layer (40); a second electrode (72) electrically connected to the second light reflecting layer (60); a current confinement layer (53) including a passing layer (531) arranged between the second light reflecting layer (60) and the second electrode (72) and configured to allow a current to pass therethrough, and an oxide layer (532) surrounding the passing layer (531); Including, the first light reflecting layer (40) is made of a material containing Al and includes a plurality of first reflecting layers (41) and a plurality of second reflecting layers (42) alternately arranged in the thickness direction (Z), the Al composition ratio of the first reflecting layers (41) is higher than the Al composition ratio of the second reflecting layers (42), the laminated structure of the first reflective layer (41) and the second reflective layer (42) is provided at a position overlapping the passing layer (531); The first light reflecting layer (40) is A side surface (512) which is an end surface in a direction perpendicular to the thickness direction (Z); a first region (441) that is provided from the side surface (512) toward the center of the opening of the insulating film (73) when viewed in the thickness direction (Z), contains Al and Zn, and has an Al composition ratio lower than that of the first reflective layer (41); Including, Surface emitting laser device.

[0125] The above description is merely illustrative. Those skilled in the art may recognize that many more possible combinations and permutations are possible other than the components and methods (manufacturing processes) listed for the purpose of describing the technology of the present disclosure. The present disclosure is intended to embrace all alternatives, modifications, and alterations that fall within the scope of the present disclosure, including the scope of the claims. [Explanation of symbols]

[0126] 10 Surface-emitting laser device 11 Top of device 12 Underside of device 13~16 Side of device 21 Substrate 211 First board surface 212 Second board surface 22 Semiconductor layer 221 Page 1 222 2nd page 30 Light generating layer 31 Active layer 32 First cladding layer 33 Second cladding layer 40 1st light reflective layer 401 Page 1 41,41A 1st reflective layer 411 Oxide layer 42 Second reflective layer 441 First area 441A Inner end 441B Bottom end 442 Second area 461 1st layer 462 2nd layer 51 Light emitting part 511 Light-emitting surface 512 Light-emitting part side 52 Separation groove 521 Inner surface 522 Outer surface 523 Bottom 53 Current confinement layer 531 Passing layer 532 Oxide layer 532A inner end 54 Frame section 541 Frame surface 542 Frame side 60 Second light reflective layer 61,61A 3rd reflective layer 611 Oxide layer 62 4th reflective layer 71 1st electrode 711 Connection 712 Aperture 712A End 714 External connection part 72 2nd electrode 73 Insulating Film 731 Aperture 731A End 732 Covering part 81 Boundary part 821 Interface 822 Interface 90 Source 91 Diffusion Area 110 Surface-emitting laser device

Claims

1. a light generating layer; a first light reflecting layer and a second light reflecting layer, the first light reflecting layer and the second light reflecting layer being made of a material containing Al and disposed on either side of the light generating layer in a thickness direction of the light generating layer; an insulating film provided on a first surface of the first light reflecting layer, the insulating film having an opening exposing a part of the first surface of the first light reflecting layer; a first electrode provided across the insulating film and the first light reflecting layer and electrically connected to the first light reflecting layer; a second electrode electrically connected to the second light reflecting layer; a current confinement layer including a passing layer disposed between the second light reflecting layer and the second electrode and configured to allow a current to pass therethrough, and an oxide layer surrounding the passing layer; Including, the first light reflective layer is made of a material containing Al and includes a plurality of first reflective layers and a plurality of second reflective layers alternately arranged in the thickness direction, an Al composition ratio of the first reflective layer is higher than an Al composition ratio of the second reflective layer, a laminated structure of the first reflective layer and the second reflective layer is provided at a position overlapping the passage layer, The first light reflective layer is A side surface which is an end surface in a direction perpendicular to the thickness direction; a first region provided between the side surface and an edge of the opening of the insulating film as viewed in the thickness direction, the first region containing Al and Zn and having a lower Al composition ratio than the first reflective layer; A surface emitting laser device comprising:

2. an inner end portion of the first region is located closer to the side surface of the first light reflecting layer than an end portion of the opening of the insulating film is when viewed from the thickness direction; 2. The surface emitting laser device according to claim 1.

3. an inner end of the first region approaches the side surface of the first light reflecting layer toward the oxide layer; 2. The surface emitting laser device according to claim 1.

4. the oxide layer extends to an inner portion beyond an edge of the opening of the insulating film; 2. The surface emitting laser device according to claim 1.

5. a distance between an inner end of the first region and the opening of the insulating film is longer than a distance between the opening of the insulating film and an inner end of the oxide layer; 2. The surface emitting laser device according to claim 1.

6. a distance between an inner end of the first region and the opening of the insulating film is shorter than a distance between the opening of the insulating film and an inner end of the oxide layer; 2. The surface emitting laser device according to claim 1.

7. a distance between an inner end of the first region and the opening of the insulating film is equal to a distance between the opening of the insulating film and an inner end of the oxide layer; 2. The surface emitting laser device according to claim 1.

8. The first region has a laminated structure of a first layer having a lower concentration than the first reflective layer and a second layer having a higher concentration than the second reflective layer.

2. The surface emitting laser device according to claim 1.

9. the first light reflecting layer includes a second region through which light from the light generating layer passes; The carrier concentration of the first region is different from the carrier concentration of the second region.

2. The surface emitting laser device according to claim 1.

10. the interface between the layers in the first region is more blurred than the interface between the layers in the second region; 10. The surface emitting laser device according to claim 9.

11. the second light reflective layer includes a plurality of third reflective layers and a plurality of fourth reflective layers alternately arranged from the first light reflective layer toward the second electrode, the third reflective layers and the fourth reflective layers are made of a material containing Al; 2. The surface emitting laser device according to claim 1.

12. The Al composition ratio of the third reflective layers is higher than the Al composition ratio of the fourth reflective layers.

12. The surface emitting laser device according to claim 11.

13. an Al composition ratio in the first region is lower than an Al composition ratio in the first reflective layer and is higher than an Al composition ratio in the second reflective layer; 2. The surface emitting laser device according to claim 1.

14. the first electrode has a circular opening that is smaller than the opening of the insulating film when viewed in the thickness direction; 2. The surface emitting laser device according to claim 1.

15. the insulating film includes a covering portion in a region located inward from the opening of the insulating film, The opening of the first electrode is formed to expose a part of the covering portion.

15. The surface emitting laser device according to claim 14.

16. the first light reflecting layer includes a first conductivity type DBR layer, the second light reflecting layer includes a DBR layer of a second conductivity type different from the first conductivity type; 2. The surface emitting laser device according to claim 1.

17. a light emitting portion that penetrates the first light reflecting layer and the light generating layer in the thickness direction to reach the second light reflecting layer and is partitioned by a separation groove that is annular when viewed in the thickness direction; The side surface of the first light reflecting layer is a light emitting portion side surface of the light emitting portion.

2. The surface emitting laser device according to claim 1.

18. The separation groove includes an inner circumferential surface and an outer circumferential surface, The side surfaces of the first light reflecting layer are the inner circumferential surface and the outer circumferential surface.

18. The surface emitting laser device according to claim 17.

19. A plurality of the light emitting units are included.

18. The surface emitting laser device according to claim 17.

20. The light emitting portion has a circular shape when viewed from the thickness direction, The passage layer of the current confinement layer is disposed at the center when viewed from the thickness direction.

18. The surface emitting laser device according to claim 17.

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