CN111769438B

CN111769438B - Surface emitting laser device

Info

Publication number: CN111769438B
Application number: CN201910260182.9A
Authority: CN
Inventors: 许聪基; 赖铭智; 林弘伟; 许文士; 郭浩中; 叶晏玮; 萧越; 向宇; 张鹏
Original assignee: Suzhou Changrui Photoelectric Co ltd
Current assignee: Suzhou Changrui Photoelectric Co ltd
Priority date: 2019-04-02
Filing date: 2019-04-02
Publication date: 2021-10-15
Anticipated expiration: 2039-04-02
Also published as: CN111769438A

Abstract

The invention discloses a surface emitting laser device. The surface emitting laser device is used for generating a laser beam and comprises an epitaxial stacked body and a protection structure. The epitaxial stack includes a first reflector layer, an active layer, and a second reflector layer. The active layer is positioned between the first reflecting mirror layer and the second reflecting mirror layer, and the epitaxial laminated body is provided with at least one oxidation groove which extends from one surface of the epitaxial laminated body to the interior of the epitaxial laminated body. The protection structure is arranged on the epitaxial lamination body and comprises a first lamination part. The first laminated part covers an inner wall surface of the oxidation trench, and the first laminated part at least comprises a stress buffer layer, an aluminum oxide layer and a covering layer. The aluminum oxide layer is sandwiched between the stress buffer layer and the covering layer.

Description

Surface emitting laser device

Technical Field

The present invention relates to a surface emitting laser device, and more particularly, to a surface emitting laser device having a moisture-proof effect.

Background

Compared with the conventional edge-emitting laser, a Vertical-cavity surface-emitting laser (VCSEL) has the advantages of lower power consumption and easier coupling with an optical fiber, and is one of the currently attracting attention.

The conventional vertical cavity surface emitting laser includes at least a P-type electrode, an N-type electrode, an active layer for generating photons, and an upper Bragg Reflector (DBR) and a lower DBR located at both sides of the active layer. A current is injected into the active layer through the P-type electrode and the N-type electrode to excite photons, and a vertical resonant cavity is formed by using upper and lower Bragg reflectors (DBRs), so that a laser beam emitted from the surface of the device (i.e., in the direction perpendicular to the active layer) can be generated.

Depending on the way the VCSEL current is limited, VCSELs can be classified as ion-embedded VCSELs and oxidized VCSELs. In the manufacturing process of the oxidized VCSEL, it is necessary to form a trench in the oxidized VCSEL. However, the trench also easily allows moisture to enter the interior of the oxide VCSEL, which results in a reduction in the lifetime of the oxide VCSEL.

In the conventional oxidized VCSEL, a single silicon nitride layer is formed in the trench to prevent moisture from entering. However, the silicon nitride layer is not dense and the micro-holes (pin-holes) in the interior thereof, instead, provide a path for moisture to enter. Therefore, the conventional oxidized VCSEL is difficult to meet the reliability requirement of the industry for the oxidized VCSEL in a high temperature (85 ℃) and high relative humidity (85%) test environment (i.e., 85 ℃/85% RH test).

Disclosure of Invention

The technical problem to be solved by the invention is to avoid the invasion of moisture into the oxidized VCSEL so that the oxidized VCSEL passes the 85 ℃/85% RH test.

In order to solve the above technical problems, one of the technical solutions of the present invention is to provide a surface emitting laser device for generating a laser beam. The surface emitting laser device includes an epitaxial stacked body and a protection structure. The epitaxial stack includes a first reflector layer, an active layer and a second reflector layer. The active layer is positioned between the first reflecting mirror layer and the second reflecting mirror layer, and the epitaxial laminated body is provided with at least one oxidation groove which extends from one surface of the epitaxial laminated body to the interior of the epitaxial laminated body. The protection structure is arranged on the epitaxial lamination body and comprises a first lamination part. The first laminated part covers an inner wall surface of the oxidation trench, and the first laminated part at least comprises a stress buffer layer, an aluminum oxide layer and a covering layer. The aluminum oxide layer is sandwiched between the stress buffer layer and the covering layer.

In order to solve the above technical problem, another technical solution of the present invention is to provide a surface emitting laser device for generating a laser beam. The surface emitting laser device includes an epitaxial stacked body and a protection structure. The epitaxial stack includes a first reflector layer, an active layer and a second reflector layer. The active layer is positioned between the first reflecting mirror layer and the second reflecting mirror layer, the epitaxial laminated body comprises at least one oxidation groove, the oxidation groove surrounds a current injection part, and the current injection part is provided with a light emitting region. The protection structure is arranged on the epitaxial stacked body and comprises a first stacked portion. The first laminated part comprises a stress buffer layer and an aluminum oxide layer covering the stress buffer layer, and the first laminated part extends from a top surface of the current injection part to the bottom of the oxidation trench along one side wall surface of the oxidation trench. A bottom end of the stress buffer layer is lower than an interface of the active layer and the first reflector layer, and the first laminated part is provided with an opening corresponding to the light emitting region.

The invention has the beneficial effect that the surface emitting laser device and the manufacturing method thereof provided by the technical scheme of the invention can effectively prevent water vapor from invading the interior of the epitaxial laminated body from the oxidation trench to damage the surface emitting laser device through the protection structure arranged on the epitaxial laminated body and comprising the first laminated part covering the inner wall surface of the oxidation trench, wherein the first laminated part at least comprises an aluminum oxide layer. In addition, the surface emitting laser device of the embodiment of the invention can pass 85 ℃/85% RH test.

For a better understanding of the features and technical content of the present invention, reference should be made to the following detailed description of the invention and accompanying drawings, which are provided for purposes of illustration and description only and are not intended to limit the invention.

Drawings

FIG. 1 is a schematic cross-sectional view of a surface emitting laser device according to an embodiment of the present invention;

fig. 2 is a partially enlarged view of the surface emitting laser device of fig. 1 in a region II.

Description of the symbols

Surface emitting laser device Z1

Epitaxial laminate 1

Base part 10

First mirror layer 111

Active layer 112

Second mirror layer 113

Confinement layer 130

Restricted aperture 130h

Platform part 11

Top surface 11a

Side surface 11b

Current injection part 11P

Light emitting region A1

Oxide trench 11H

Side wall surface S1

Protective structure 2

First lamination portion 21

Opening 21h

First alumina layer 211

Stress buffer layer 210

First cladding layer 212

Single layer portion 23

Second laminate part 22

Second alumina layer 220

Second capping layer 221

Planarization layer 24

Outer protective layer 25

Electrode structure 3

Annular electrode layer 30

Electrode pad 31

Detailed Description

The following is a description of the embodiments of the "surface emitting laser device" disclosed in the present invention with reference to specific embodiments, and those skilled in the art will understand the advantages and effects of the present invention from the disclosure of the present specification. The invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. The drawings of the present invention are for illustrative purposes only and are not intended to be drawn to scale. The following embodiments will further explain the related art of the present invention in detail, but the disclosure is not intended to limit the scope of the present invention.

Please refer to fig. 1 and fig. 2. Fig. 1 is a schematic cross-sectional view of a surface emitting laser device according to an embodiment of the invention, and fig. 2 is a partially enlarged view of the surface emitting laser device of fig. 1 in a region II. The surface emitting laser device Z1 is used for generating a laser beam and includes an epitaxial stacked body 1 and a protection structure 2.

In detail, the epitaxial stacked body 1 includes a substrate 10, a first mirror layer 111, an active layer 112, and a second mirror layer 113. The first mirror layer 111, the active layer 112 and the second mirror layer 113 are all located on the base portion 10, and the active layer 112 is located between the first mirror layer 111 and the second mirror layer 113.

The base portion 10 may be a doped group III-V semiconductor substrate, such as a gallium arsenide N-type (GaAs) substrate, an arsenic phosphide N-type (InP) substrate, an Aluminum Nitride (AIN) substrate, or an Indium Nitride (InN) substrate. The first mirror layer 111, the active layer 112, and the second mirror layer 113 are sequentially provided on the base portion 10.

The first mirror layer 111 and the second mirror layer 113 may be Distributed Bragg Reflectors (DBRs) formed by alternately stacking two kinds of thin films having different refractive indexes.

The first mirror layer 111 and the second mirror layer 113 are formed by stacking a plurality of pairs of films with high refractive index and films with low refractive index. In one embodiment, the first mirror layer 111 is an n-type DBR mirror and the second mirror layer 113 is a p-type DBR mirror.

As shown in fig. 1, the active layer 112 is formed on the first mirror layer 111 and includes a plurality of layers for forming multiple quantum wells. The active layer 112 is located between the first mirror layer 111 and the second mirror layer 113, and is excited by electrical energy to generate a light beam. The light beam generated by the active layer 112 is amplified in gain by reflection resonance back and forth between the first mirror layer 111 and the second mirror layer 113, and finally exits from the second mirror layer 113 to form a laser beam.

In the present embodiment, the cross-sectional widths of the first mirror layer 111, the active layer 112, and the second mirror layer 113 are all smaller than the cross-sectional width of the base portion 10. Accordingly, the first mirror layer 111, the active layer 112, and the second mirror layer 113 collectively form a mesa 11. The platform portion 11 has a top surface 11a and a side surface 11 b. In addition, the terrace portion 11 can be distinguished into a current injection portion 11P and a peripheral portion (not numbered), the current injection portion 11P having a light emitting area a 1.

In this embodiment, the epitaxial stacked body 1 has at least one oxidation trench 11H in the terrace portion 11. Specifically, the oxide trench 11H extends from the top surface 11a of the terrace portion 11 toward the base portion 10. In one embodiment, the depth of the oxide trench 11H is greater than the thickness of the second mirror layer 113.

In another embodiment, the depth of the oxide trench 11H is greater than the sum of the thicknesses of the second mirror layer 113 and the active layer 112. That is, the oxide trench 11H extends toward the base portion 10 into the first mirror layer 111 under the active layer 112.

In the present embodiment, the oxide trench 11H has a ring shape in a plan view, and surrounds the current injection portion 11P. Accordingly, one of the sidewall surfaces S1 of the oxide trench 11H is the sidewall of the current injection portion 11P. In other embodiments, the number of the oxidation trenches 11H is plural, and is disposed around the current injection portion 11P.

In addition, the epitaxial stacked body 1 further includes a confinement layer 130 located in the second mirror layer 113, and the confinement layer 130 has a confinement hole 130 h.

It should be noted that the confinement layer 130 is formed by performing an oxidation process. Specifically, at least one high aluminum-containing layer is formed among the plurality of layers of the second mirror layer 113. Therefore, when the oxidation process is performed, the high al content layer is easily oxidized from the portion exposed on the sidewall surface S1 of the oxide trench 11H, and the confinement layer 130 is formed.

As shown in fig. 1, the confinement layer 130 extends radially from the sidewall surface S1 of the oxide trench 11H toward the current injection portion 11P to define an via 130H. Since the resistance of the confinement layer 130 is high, the current flowing into the current injection portion 11P enters the active layer 112 only through the confinement hole 130h, thereby increasing the current density.

However, after the surface emitting laser device Z1 is completed, the high aluminum content layer of the second mirror layer 113 may be oxidized due to moisture absorption. The oxidized high al layer and other layers of the second mirror layer 113 may generate stress due to material difference, which may cause damage to the surface emitting laser device Z1. Accordingly, the surface emitting laser device Z1 according to the embodiment of the present invention further includes the protective structure 2 to prevent moisture from entering the epitaxial stacked body 1.

As shown in fig. 1, the protection structure 2 is disposed on the epitaxial stacked body 1 and includes at least a first stacked portion 21.

Further, the first stack portion 21 is disposed on the top surface 11a of the mesa portion 11 and extends from the top surface 11a to the bottom of the oxide trench 11H along the sidewall surface S1 of the oxide trench 11H. That is, the first stacked layer portion 21 covers the inner wall surfaces (including the sidewall surfaces and the bottom surfaces) of the oxide trench 11H.

Since the first stacked portion 21 is mainly used to prevent moisture from entering the interior of the epitaxial stacked body 1 from the oxide trench 11H, in the present embodiment, the first stacked portion 21 at least includes a first alumina layer 211. Since the first alumina layer 211 is dense and has less micro-pores (pin-holes), it is possible to effectively prevent moisture from invading. In one embodiment, the dense aluminum oxide layer may be formed by an Atomic Layer Deposition (ALD) process. That is, the first alumina layer 211 is an atomic layer deposition alumina layer (ALD-Al)₂O₃)。

In addition, as shown in fig. 2, in the present embodiment, the first stacked portion 21 further includes a stress buffer layer 210 in addition to the first aluminum oxide layer 211, and the first aluminum oxide layer 211 covers the stress buffer layer 210.

That is, before forming the first alumina layer 211, the stress buffer layer 210 is formed on the top surface 11a of the mesa portion 11 and in the oxide trench 11H, and then the first alumina layer 211 covering the stress buffer layer 210 is formed. The stress buffer layer 210 may be a silicon nitride layer or a silicon oxide layer, but the invention is not limited thereto.

In the present invention, the stress buffer layer 210 is formed on the top surface 11a of the mesa 11 and in the oxide trench 11H, so as to avoid the adverse effect on the surface emitting laser device Z1 caused by the stress generated between the first alumina layer 211 and the mesa 11 due to the different materials.

On the other hand, although the stress buffer layer 210 has a certain blocking capability against moisture, the stress buffer layer 210 has many pores therein. These pores may provide a path for moisture to enter into the current injection portion 11P. Therefore, the dense first alumina layer 211 is formed on the stress buffer layer 210, and the moisture invasion can be blocked more effectively.

That is, the stress buffer layer 210 and the first alumina layer 211 can not only effectively block moisture intrusion, but also reduce the stress between the first alumina layer 211 and the mesa 11 due to the material difference. It should be noted that too thin a thickness of the first alumina layer 211 may not effectively block moisture, too thick a thickness may increase the manufacturing process and material cost, and too much stress may be generated between the first alumina layer and the mesa portion 11.

Accordingly, in one embodiment, the thickness of the first alumina layer 211 may be between 0.02 μm and 0.5 μm, so as to prevent excessive stress from being generated between the first lamination portion 21 and the platform portion 11 while providing a better waterproof effect. In a preferred embodiment, the thickness of the first alumina layer 211 may be between 0.02 μm and 0.5 μm. In addition, the thickness of the stress buffer layer 210 may be between 0.05 μm and 0.5 μm.

However, the thickness of the first alumina layer 211 and the stress buffer layer 210 are not necessarily the same as long as the above-mentioned object can be achieved. It is noted that, in fig. 2, the thickness of the stress buffer layer 210 is greater than that of the first alumina layer 211. In another embodiment, the first alumina layer 211 may have a thickness greater than that of the stress buffer layer 210 for better moisture barrier effect.

In the present embodiment, since the oxide trench 11H extends into the first mirror layer 111, the bottom end of the stress buffer layer 210 is lower than the interface between the active layer 112 and the first mirror layer 111.

As shown in fig. 2, in the present embodiment, the first stack portion 21 further includes a first capping layer 212 on the first alumina layer 211. Accordingly, the first alumina layer 211 is sandwiched between the stress buffer layer 210 and the first capping layer 212. In one embodiment, the material of the first cap layer 212 is nitride, such as: silicon nitride, but the invention is not limited. In another embodiment, the first cover layer 212 may also be omitted.

In addition, the total thickness of the first stack portion 21 is between 0.05 μm and 1 μm, wherein the thickness of the stress buffer layer 210, the thickness of the first aluminum oxide layer 211, and the thickness of the first capping layer 212 can be adjusted according to actual requirements.

In view of the above, in the embodiment of the present invention, since the first stacked portion 21 includes the dense first alumina layer 211, moisture can be prevented from entering the epitaxial stacked body 1. It is noted that, in the embodiment of the invention, the stress buffer layer 210, the first alumina layer 211 and the first capping layer 212 do not completely cover the top surface of the current injection portion 11P.

Referring to fig. 2, in particular, the first stacked portion 21 has an opening 21h corresponding to the limiting hole 130h (or the light emitting region a1) on the current injection portion 11P to avoid affecting the light emitting efficiency of the laser beam. In other words, the first stack portion 21 partially covers the top surface of the current injection portion 11P.

As shown in fig. 2, the surface emitting laser device Z1 according to the embodiment of the present invention further includes an electrode structure 3, and the electrode structure 3 is disposed on the current injection portion 11P and electrically connected to the second mirror layer 113.

Specifically, the electrode structure 3 includes a ring-shaped electrode layer 30 and electrode pads 31 disposed on the ring-shaped electrode layer 30. A part of the ring-shaped electrode layer 30 is located in the opening 21h of the first stacked layer portion 21 and contacts the top surface of the current injection portion 11P. That is, the ring-shaped electrode layer 30 extends from the upper surface of the first stack portion 21 into the opening 21 h.

In addition, the opening of the ring-shaped electrode layer 30 defines the light emitting area a1 and corresponds to the confinement holes 130h of the confinement layer 130. Accordingly, the aperture of the opening of the ring-shaped electrode layer 30 defines the area of the light emitting region a1, and the light emitting region a1 and the confinement holes 130h overlap in a vertical direction.

The electrode pads 31 are disposed on the ring-shaped electrode layer 30 and electrically connected to an external control circuit. In the embodiment of the present invention, the surface emitting laser device Z1 further includes another electrode structure (not shown) electrically connected to the first mirror layer 111. A current path through the active layer 112 is formed between the two electrode structures.

Referring to fig. 2, the protection structure 2 of the present embodiment further includes a single-layer portion 23. Specifically, at least a part of the single-layer portion 23 is located in the opening 21h of the first stacked layer portion 21 and covers the light-emitting region a 1. That is, the annular electrode layer 30 and the single-layer portion 23 are located in the opening 21h, and the single-layer portion 23 is formed in the opening of the annular electrode layer 30 to cover the light-emitting region a 1.

The material of the single-layer portion 23 may be selected to be moisture-resistant to provide protection to the light-emitting region a 1. Therefore, on the other hand, the difference in lattice constant or the difference in thermal expansion coefficient between the material of the single-layer portion 23 and the material of the current injection portion 11P cannot be large. Accordingly, the material of the single layer portion 23 may be different from the first alumina layer 211. In one embodiment, the material of the single-layer portion 23 may be silicon nitride.

In addition, if the thickness of the single-layer portion 23 is too thin, moisture cannot be effectively prevented from entering the light emitting region a1, and if the thickness is too thick, the light emitting efficiency of the laser beam is affected. Therefore, in one embodiment, the thickness of the single-layer portion 23 is between 0.05 μm and 0.6 μm, which provides better protection for the light emitting region a1, and the transmittance of the laser beam to the single-layer portion 23 can be higher than 80%.

Referring to fig. 1, the protection structure 2 of the embodiment of the invention further includes a second stacked portion 22, and the second stacked portion 22 covers a side surface 11b of the epitaxial stacked body 1 (the mesa portion 11). In the embodiment, the second stacked portion 22 includes a second aluminum oxide layer 220 and a second capping layer 221, the second aluminum oxide layer 220 directly contacts the side surface 11b of the epitaxial stacked body 1, and the second capping layer 221 covers the first aluminum oxide layer 211.

In one embodiment, the second alumina layer 220 and the first alumina layer 211 can be formed simultaneously in the same deposition process. That is, the first alumina layer 211 and the second alumina layer 220 can be formed simultaneously by performing an atomic layer deposition process. Similarly, the first capping layer 212 and the second capping layer 221 may be formed in the same deposition process.

Accordingly, the total thickness of the first stacked part 21 may be greater than that of the second stacked part 22. That is, in the present embodiment, the protective structure 2 may have different thicknesses in different regions. Further, the total thickness of the second stacked portion 22 is between 0.04 μm and 0.8 μm.

With reference to fig. 1 and 2, the protection structure 2 of the present embodiment further includes a planarization layer 24 and an outer protection layer 25.

The planarization layer 24 is disposed on the top surface 11a of the mesa portion 11, and a portion of the planarization layer 24 is located in the oxidation trench 11H. Further, the planarization layer 24 is disposed on the first stack portion 21 and fills the oxide trench 11H. The material of the planarization layer 24 is a polymer material, such as Polyimide (PI), Benzocyclobutene (BCB), or other suitable materials.

The outer protective layer 25 covers the epitaxial stacked body 1 to protect the surface emitting laser device Z1. As shown in fig. 1, the outer protective layer 25 is disposed on the top surface 11a and the side surface 11b of the terrace portion 11. A portion of the outer protective layer 25 disposed on the top surface 11a covers the planarization layer 24, and another portion of the outer protective layer 25 disposed on the side surface 11b covers the second stacked portion 22.

It should be noted that, in one embodiment, the outer passivation layer 25 and the single-layer portion 23 on the light emitting region a1 are formed in the same deposition process. Accordingly, the material of the outer protection layer 25 is the same as that of the single-layer portion 23, and the outer protection layer 25 and the single-layer portion 23 have substantially the same thickness. The outer passivation layer 25 of this embodiment is a silicon nitride layer.

However, in other embodiments, the outer protection layer 25 and the single-layer portion 23 may be formed by different deposition processes. In this case, the material of the outer protective layer 25 is not necessarily the same as the material of the single-layer portion 23.

In addition, the outer passivation layer 25 and the single-layer portion 23 are separated from each other to define a contact opening (not numbered) and expose a portion of the ring-shaped electrode layer 30. The electrode pads 31 of the electrode structure 3 may be electrically connected to the ring-shaped electrode layer 30 through contact openings.

[ advantageous effects of the embodiments ]

The invention has the beneficial effect that the surface emitting laser device and the manufacturing method thereof provided by the technical scheme of the invention can effectively prevent moisture from invading the interior of the epitaxial laminated body 1 from the oxidation trench to damage the surface emitting laser device Z1 through the protection structure 2 arranged on the epitaxial laminated body 1 and comprising the first laminated part 21 covering the inner wall surface of the oxidation trench 11H, wherein the first laminated part 21 at least comprises the alumina layer 211. In addition, the surface emitting laser device Z1 of the embodiment of the invention can pass the 85 ℃/85% RH test.

The disclosure is only a preferred embodiment of the invention, and is not intended to limit the scope of the invention, so that all equivalent technical changes made by using the contents of the specification and the drawings are included in the scope of the invention.

Claims

1. A surface-emitting laser apparatus for generating a laser beam, comprising:

an epitaxial stack comprising a first mirror layer, an active layer, a second mirror layer, wherein the active layer is located between the first mirror layer and the second mirror layer, the epitaxial stack comprising at least one oxidation trench; and

the protection structure is arranged on the epitaxial laminated body and comprises a first laminated part, wherein the first laminated part covers the inner wall surface of the oxidation groove, the first laminated part at least comprises a stress buffer layer, a first aluminum oxide layer and a first covering layer, and the first aluminum oxide layer is clamped between the stress buffer layer and the first covering layer.

2. The surface emitting laser device of claim 1, wherein the oxide trench surrounds a current injection portion having a light emitting region, and the protection structure further comprises a single layer portion disposed on a top surface of the current injection portion and covering the light emitting region.

3. The surface-emitting laser device of claim 2, wherein the first stacked portion has an opening corresponding to the light emitting region, at least a portion of the single-layer portion is disposed in the opening to cover the light emitting region, and the thickness of the single-layer portion is between 0.05 μm and 0.6 μm.

4. The surface-emitting laser device as claimed in claim 1, wherein the total thickness of the first stack portion is between 0.05 μm and 1 μm, and the thickness of the first alumina layer is between 0.02 μm and 0.5 μm.

5. The surface-emitting laser device of claim 1, wherein the protective structure further comprises a second stacked portion that covers a side surface of the epitaxial stacked body, the second stacked portion comprising a second aluminum oxide layer and a second cover layer, and the second aluminum oxide layer directly contacting the side surface of the epitaxial stacked body.

6. The surface-emitting laser apparatus of claim 5, wherein the protective structure further comprises an outer protective layer covering at least the second stack portion.

7. The surface-emitting laser apparatus of claim 1, wherein the structure of the epitaxial stacked body further comprises a base portion on which the first mirror layer, the active layer, and the second mirror layer are disposed, and cross-sectional widths of the first mirror layer, the active layer, and the second mirror layer are smaller than a cross-sectional width of the base portion to collectively form a terrace portion.

8. The surface-emitting laser device of claim 1, wherein the stress buffer layer is made of silicon nitride and has a thickness of 0.02 μm to 0.5 μm.

9. A surface-emitting laser apparatus for generating a laser beam, comprising:

the epitaxial stack body comprises a first reflector layer, an active layer and a second reflector layer, wherein the active layer is positioned between the first reflector layer and the second reflector layer, the epitaxial stack body comprises at least one oxidation groove, the oxidation groove surrounds a current injection part, and the current injection part is provided with a luminous region; and

and the protective structure is arranged on the epitaxial laminated body and comprises a first laminated part, wherein the first laminated part comprises a stress buffer layer and an aluminum oxide layer covering the stress buffer layer, the first laminated part extends from the top surface of the current injection part to the bottom of the oxidation trench along the side wall surface of the oxidation trench, the bottom end of the stress buffer layer is lower than the interface of the active layer and the first reflector layer, and the first laminated part is provided with an opening corresponding to the light emitting region.

10. The surface-emitting laser device of claim 9, wherein the protective structure further comprises a single-layer portion covering the light emitting region, and the single-layer portion is made of a different material from the aluminum oxide layer.