CN118117442A - Manufacturing method of VCSEL device and VCSEL device - Google Patents

Abstract

The present invention discloses a method for manufacturing a VCSEL device and a VCSEL device. A nitrogen (hydrogen or air)/InP periodic structure satisfying the Bragg reflection condition is used as an N-type DBR structure suitable for an InP substrate, a dielectric film periodic structure satisfying the Bragg reflection condition and having different refractive indices is used as a P-type DBR structure, and a tunnel junction is used to manufacture the P-type electrode of the VCSEL device and the current limiting structure of the VCSEL device, thereby making it possible to mass-produce long-wavelength VCSEL devices.

Description

Method for manufacturing VCSEL device and VCSEL device

Technical Field

The present invention belongs to the technical field of semiconductor processes, and in particular relates to a method for manufacturing a VCSEL device and the VCSEL device.

Background technique

VCSEL (Vertical Cavity Surface Emitting Laser) lasers have many advantages in modern society, such as low threshold current, low energy consumption, circular spot, chip manufacturing and testing without cleavage, easy realization of high-density two-dimensional array and optoelectronic integration, etc.

At present, the technology for making 650nm-980nm wavelength VCSEL chips on GaAs substrates is very mature and has been industrialized, but long-wavelength VCSEL chips based on InP substrates have not been industrialized. The reason is that the optical refractive index contrast of materials suitable for InP substrate lattices grown on InP substrates is very limited, and the refractive index difference between different materials is relatively small. Therefore, there is no suitable InP-based epitaxial material for preparing DBR structures, and thus there is no mature technology to prepare long-wavelength VCSEL chips on InP substrates.

The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

Summary of the invention

The object of the present invention is to provide a method for manufacturing a VCSEL device and a VCSEL device, which can manufacture a long-wavelength VCSEL device based on an InP substrate, making it possible to mass-produce long-wavelength VCSEL devices.

In order to achieve the above object, a specific embodiment of the present invention provides a method for manufacturing a VCSEL device, comprising:

Providing an InP substrate, the InP substrate having a first surface and a second surface opposite to each other, the first surface having a first epitaxial region and a second epitaxial region;

Growing an epitaxial structure on the first surface, the epitaxial structure comprising a buffer layer, an N-type InGaAs/InP periodic structure, a resonant cavity, a P-type heavily doped layer, and an N-type heavily doped layer grown in sequence;

Etching the epitaxial structure in the second epitaxial region to the buffer layer to expose a portion of the buffer layer or etching the epitaxial structure in the second epitaxial region to the substrate to expose a portion of the substrate;

Etching the InGaAs layer in the N-type InGaAs/InP periodic structure to remove part of the InGaAs layer in the direction extending from the second epitaxial region to the first epitaxial region to form a cavity;

Growing an insulating epitaxial material in the second epitaxial region to form an insulating epitaxial structure to block the cavity in the InGaAs layer and support the InP layer;

removing a portion of the N-type heavily doped layer to expose the P-type heavily doped layer;

forming a P-type electrode on the exposed surface of the P-type heavily doped layer and a portion of the surface of the N-type heavily doped layer;

forming a P-type DBR structure on the P-type electrode, the N-type heavily doped layer and the insulating epitaxial structure;

Etching the P-type DBR structure to expose a portion of the P-type electrode;

An N-type electrode is formed on the second surface of the InP substrate.

In one or more embodiments of the present invention, an insulating epitaxial structure is grown in the second epitaxial region under a protective gas environment to block the cavity in the InGaAs layer;

The cavity is filled with the protective gas, and the protective gas and the InP layer are alternately arranged to form an N-type DBR structure.

In one or more embodiments of the present invention, the height of the cavity is substantially equal to the thickness of the InGaAs layer in which the cavity is located; and the area of the cavity is not less than the area of the light outlet of the VCSEL device.

In one or more embodiments of the present invention, the protective gas is selected from nitrogen or hydrogen.

In one or more embodiments of the present invention, the protective gas is selected from air.

In one or more embodiments of the present invention, the insulating epitaxial structure grows to be flush with the epitaxial structure.

In one or more embodiments of the present invention, the material of the insulating epitaxial structure is an InP material containing Fe.

In one or more embodiments of the present invention, an H ₂ SO ₄ :H ₂ O ₂ :H ₂ O solution is used to chemically etch the InGaAs layer in the N-type InGaAs/InP periodic structure.

In one or more embodiments of the present invention, the epitaxial structure and the insulating epitaxial structure are grown by metal organic chemical vapor deposition epitaxy or homoepitaxial growth.

In one or more embodiments of the present invention, forming a P-type DBR structure on the P-type electrode, the N-type heavily doped layer and the insulating epitaxial structure includes:

A first dielectric film layer having a first refractive index and a second dielectric film layer having a second refractive index are alternately plated on the P-type electrode, the N-type heavily doped layer and the insulating epitaxial structure, wherein the first refractive index is not equal to the second refractive index.

A specific embodiment of the present invention also provides a VCSEL device, including:

An InP substrate having a first surface and a second surface opposite to each other, wherein the first surface has a first epitaxial region and a second epitaxial region;

An N-type DBR structure is formed on the first epitaxial region, wherein the N-type DBR structure comprises an InGaAs layer and an InP layer which are alternately arranged in sequence, a cavity is formed in the InGaAs layer, and the cavity is filled with a protective gas;

A resonant cavity formed on the N-type DBR structure;

A tunnel junction is formed on the resonant cavity, wherein the tunnel junction includes a P-type heavily doped layer and an N-type heavily doped layer formed in sequence, and the N-type heavily doped layer exposes a portion of the P-type heavily doped layer;

A P-type electrode formed on the surface of the P-type heavily doped layer and extending to the surface of the N-type heavily doped layer;

an insulating epitaxial structure formed on the second epitaxial region of the first surface;

A P-type DBR structure is formed on the tunnel junction, a portion of the P-type electrode and the insulating epitaxial structure; and,

An N-type electrode is formed on the second surface of the InP substrate.

In one or more embodiments of the present invention, the VCSEL device further includes a buffer layer formed on the first surface of the InP substrate.

In one or more embodiments of the present invention, the VCSEL device further includes a buffer layer formed on the first epitaxial region of the first surface of the InP substrate.

In one or more embodiments of the present invention, the insulating epitaxial structure is arranged in contact with the N-type DBR structure to block the cavity in the InGaAs layer.

In one or more embodiments of the present invention, the sum of the thicknesses of the N-type DBR structure, the resonant cavity, and the tunnel junction is equal to the thickness of the insulating epitaxial structure.

In one or more embodiments of the present invention, the material of the insulating epitaxial structure is an InP material containing Fe.

In one or more embodiments of the present invention, the height of the cavity is substantially equal to the thickness of the InGaAs layer in which the cavity is located; and the area of the cavity is not less than the area of the light outlet of the VCSEL device.

In one or more embodiments of the present invention, the protective gas is selected from nitrogen or hydrogen.

In one or more embodiments of the present invention, the protective gas is selected from air.

In one or more embodiments of the present invention, the resonant cavity includes an N-type InP layer, an N-type separation confinement layer, an active region, a P-type separation confinement layer, and a P-type InP layer, which are formed in sequence.

In one or more embodiments of the present invention, the P-type DBR structure includes a first dielectric film layer having a first refractive index and a second dielectric film layer having a second refractive index which are alternately arranged in sequence, wherein the first refractive index is not equal to the second refractive index.

Compared with the prior art, the VCSEL device manufacturing method and VCSEL device of the present invention use the nitrogen (hydrogen or air)/InP periodic structure that meets the Bragg reflection condition as the N-type DBR structure suitable for the InP substrate, providing a new idea for manufacturing long-wavelength VCSEL devices. The reflectivity of the N-type DBR structure to the wavelength light of the VCSEL device is greater than 99.9%, and the refractive index difference between the InP layer and the nitrogen (hydrogen or air) is fixed and easy to control.

The manufacturing method and VCSEL device of the present invention use a tunnel junction to manufacture the P-type electrode of the VCSEL device, which is simpler, more convenient and more efficient in terms of process. In addition, the Schottky structure formed between the metal material (GeAu/Ni/Au) of the P-type electrode and the P-type heavily doped layer can also limit the injection of the current injected into the VCSEL device, and can be used as a current limiting structure of the VCSEL device, having a current limiting effect.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

FIG1 is a schematic diagram of the structure of a VCSEL device in one embodiment of the present invention;

FIG2 is a process flow chart of a method for manufacturing a VCSEL device in one embodiment of the present invention;

3a to 3h are schematic diagrams of process steps of a method for manufacturing a VCSEL device in one embodiment of the present invention.

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

As mentioned in the background technology, VCSEL lasers have the advantages of low threshold current, low energy consumption, circular spot, chip manufacturing and detection can be completed without cleavage, and high-density two-dimensional array and optoelectronic integration are easy to achieve, and are widely used in modern society. At present, the technology of making 650nm-980nm wavelength VCSEL chips on GaAs substrates is very mature and has been industrialized, but long-wavelength VCSEL chips based on InP substrates have not been industrialized. The reason is that the optical refractive index comparison of materials suitable for InP substrate lattices grown on InP substrates is very limited, and the refractive index difference of different materials is relatively small. Therefore, there is no suitable InP-based epitaxial material for preparing DBR structure, and thus there is no mature technology to prepare long-wavelength VCSEL chips on InP substrates.

Based on this, the present application proposes a new process route for manufacturing long-wavelength VCSEL devices and long-wavelength VCSEL devices, using a nitrogen (hydrogen or air)/InP periodic structure that meets the Bragg reflection condition as an N-type DBR structure suitable for an InP substrate, and using a dielectric film periodic structure with different refractive indices that meets the Bragg reflection condition as a P-type DBR structure, while using a tunnel junction to manufacture the P-type electrode of the VCSEL device and the current limiting structure of the VCSEL device, thereby making it possible to mass-produce long-wavelength VCSEL devices.

As shown in FIG. 1 , a VCSEL device in an embodiment of the present invention includes: an InP substrate 10 , a buffer layer 11 , an N-type DBR structure 20 , a resonant cavity 30 , a tunnel junction 40 , a P-type electrode 50 , an insulating epitaxial structure 60 , a P-type DBR structure 70 and an N-type electrode 80 .

The InP substrate 10 is an N-type doped substrate. The InP substrate 10 has a first surface and a second surface opposite to each other. The first surface has a first epitaxial region 101 and a second epitaxial region 102 .

The buffer layer 11 is an N-type InP buffer layer, and the buffer layer 11 is formed on the entire first surface of the InP substrate 10 ; or, the buffer layer 11 is formed on the first epitaxial region 101 of the first surface of the InP substrate 10 .

The N-type DBR structure 20 is formed on the buffer layer 11 in the first epitaxial region 101 and/or the second epitaxial region 102. The N-type DBR structure 20 includes an InGaAs layer 20a and an InP layer 20b which are alternately arranged in sequence. The InGaAs layer 20a is partially chemically etched away to form a cavity 21, and the cavity 21 is filled with a protective gas. The thickness of the InP layer 20b and the protective gas meets the Bragg reflection condition, and the reflectivity of the N-type DBR structure 20 to the device wavelength light is greater than 99.9%.

In this embodiment, the cavity 21 can be formed in the following manner: first, the N-type DBR structure 20, the resonant cavity 30 and the tunnel junction 40 are all grown on the buffer layer 11 in sequence; then, the epitaxial structure (N-type DBR structure 20, the resonant cavity 30 and the tunnel junction 40) above the buffer layer 11 on the second epitaxial region 102 is etched away by photolithography, ICP or RIE process; finally, the InGaAs layer 20a on the upper part of the first epitaxial region 101 is partially removed by chemical etching method, and finally the cavity 21 is formed. The cavity 21 is located on the side of the InGaAs layer 20a close to the second epitaxial region 102, the height of the cavity 21 is approximately equal to the thickness of the InGaAs layer 20a where it is located, and the area of the cavity 21 is not less than the area of the light outlet of the VCSEL device.

In this embodiment, the protective gas in the cavity 21 is selected from nitrogen, hydrogen or air.

The resonant cavity 30 is formed on the N-type DBR structure 20. The resonant cavity 30 includes an N-type InP layer 31, an N-type separation confinement layer 32, an active region 33, a P-type separation confinement layer 34 and a P-type InP layer 35, which are formed in sequence. Among them, the active region 33 adopts an InGaAsP/InGaAsP strained quantum well structure.

The tunnel junction 40 is formed on the resonant cavity 30 , and the tunnel junction 40 includes a P-type heavily doped layer 41 and an N-type heavily doped layer 42 formed in sequence. A portion of the N-type heavily doped layer 42 is removed by photolithography, ICP or RIE to expose a portion of the P-type heavily doped layer 41 .

In this embodiment, the doping concentration of the P-type heavily doped layer 41 is greater than 1E19/cm ³ , and the doping concentration of the N-type heavily doped layer 42 is greater than 1E19/cm ³ . The thickness of the N-type heavily doped layer 42 is in the nanometer order.

The P-type electrode 50 is formed on the exposed surface of the P-type heavily doped layer 41 and extends to the surface of the N-type heavily doped layer 42 .

The metal (GeAu/Ni/Au) used to make the electrode here contacts the N-type heavily doped layer 42 to form an ohmic contact, and the metal contacts the exposed portion of the P-type heavily doped layer 41 to form a Schottky structure. The current applied to the VCSEL device only flows through the N-type heavily doped layer 42, and cannot flow through the exposed portion of the P-type heavily doped layer 41. The Schottky structure formed here plays a role in limiting the injected current, thereby reducing the threshold current of the VCSEL device.

The insulating epitaxial structure 60 is formed on the second epitaxial region 102 of the first surface. The insulating epitaxial structure 60 is arranged in contact with the N-type DBR structure 20 to block the cavity in the InGaAs layer 20a and support the entire VCSEL device. The sum of the thickness of the N-type DBR structure 20, the resonant cavity 30 and the tunnel junction 40 is equal to the thickness of the insulating epitaxial structure 60.

In this embodiment, the material of the insulating epitaxial structure 60 is an InP material containing Fe.

The P-type DBR structure 70 is formed on the tunnel junction 40, a portion of the P-type electrode 50 and the insulating epitaxial structure 60. The P-type DBR structure 70 includes a first dielectric film layer 70a having a first refractive index and a second dielectric film layer 70b having a second refractive index, which are alternately arranged in sequence, wherein the first refractive index is not equal to the second refractive index, and there is a certain difference between the first refractive index and the second refractive index. The thickness of the high refractive index and low refractive index dielectric films meets the Bragg reflection condition, and the reflectivity of the device wavelength light reaches more than 90%.

The N-type electrode 80 is formed on the second surface of the InP substrate 10 .

Referring to FIG. 2 and FIG. 3a to FIG. 3h , an embodiment of the present invention further provides a method for manufacturing a VCSEL device, which specifically includes the following steps:

S1, providing an InP substrate, and growing an epitaxial structure on the InP substrate.

As shown in FIG. 3 a , the InP substrate 10 is an N-type doped substrate. The InP substrate 10 has a first surface and a second surface opposite to each other. The first surface has a first epitaxial region 101 and a second epitaxial region 102 .

An epitaxial structure is grown on the entire first surface of the InP substrate 10, specifically including: using metal organic chemical vapor deposition (MOCVD) epitaxial or homoepitaxial growth technology, first growing an N-type InP buffer layer 11, an N-type doped InGaAs/InP periodic structure, a resonant cavity 30, a P-type heavily doped layer 41 and an N-type heavily doped layer 42 on the InP substrate 10.

S2, etching the epitaxial structure in the second epitaxial region to the buffer layer to expose a portion of the buffer layer; or, etching the epitaxial structure in the second epitaxial region to the substrate to expose a portion of the substrate.

In this embodiment, etching to the substrate 10 is taken as an example for detailed description.

Referring to FIG. 3 b , the surface of the epitaxial structure is etched by a yellow light process and an ICP etching technique to expose the substrate 10 of the second epitaxial region 102 .

It can be understood that the yellow light process is a process in the semiconductor industry that involves coating silicon wafers and other chips with glue, soft baking, exposure, development, and hard baking to make them photoetch a certain pattern.

S3, corroding the InGaAs layer in the N-type doped InGaAs/InP periodic structure to form a cavity.

As shown in _FIG3c , the InGaAs layer 20a in the N-type doped InGaAs/InP periodic structure is chemically etched using _{a H2SO4} : _H2O2 : _H2O solution to remove part of the InGaAs layer 20a extending from the second epitaxial region 102 to the first epitaxial region 101, thereby forming a cavity 21. The height of the cavity 21 is substantially equal to the thickness of the InGaAs layer 20a in which it is located. The area of the cavity 21 is not less than the area of the light outlet of the VCSEL device.

S4, growing an insulating epitaxial structure in the second epitaxial region to seal the cavity in the InGaAs layer.

As shown in FIG. 3d, in a protective gas environment, an insulating epitaxial structure 60 is grown in the second epitaxial region 102 by MOCVD to block the cavity 21 in the InGaAs layer 20a and support the InP layer at the hollowed-out position. The insulating epitaxial structure 60 grows to be flush with the epitaxial structure. The cavity 21 in the InGaAs layer 20a is backfilled with protective gas during the MOCVD growth process, and the protective gas and the InP layer 20b are alternately arranged to form an N-type DBR structure 20. The protective gas is selected from nitrogen, hydrogen or air.

In this embodiment, the InP layer 20b and nitrogen (hydrogen or air) constituting the N-type DBR structure 20 have a large refractive index difference, and the refractive index difference between the two is fixed and easy to control. The reflectivity of this N-type DBR structure to the wavelength light of the VCSEL device is greater than 99.9%.

In a preferred embodiment, the material of the insulating epitaxial structure 60 is an InP material containing Fe.

S5, removing a portion of the N-type heavily doped layer to expose the P-type heavily doped layer.

3 e , a portion of the N-type heavily doped layer 42 is removed by using a yellow light process and an ICP etching process to expose the P-type heavily doped layer 41 .

S6, forming a P-type electrode on the exposed surface of the P-type heavily doped layer and a portion of the surface of the N-type heavily doped layer.

3 f , a P-type electrode 50 is prepared on the exposed surface of the P-type heavily doped layer 41 and a portion of the surface of the N-type heavily doped layer 42 by using a yellow light process and an Ebeam metal evaporation process.

S7, forming a P-type DBR structure on the P-type electrode, the N-type heavily doped layer and the insulating epitaxial structure.

As shown in FIG3g, a first dielectric film layer 70a having a first refractive index and a second dielectric film layer 70b having a second refractive index are alternately plated on the P-type electrode 50, the N-type heavily doped layer 42 and the insulating epitaxial structure 60 using an AR coating device, wherein the first refractive index is higher than the second refractive index and there is a certain difference between the first refractive index and the second refractive index. The thickness of the high refractive index and low refractive index dielectric films meets the Bragg reflection condition, and the reflectivity of the device wavelength light reaches more than 90%.

S8, etching the P-type DBR structure to expose a portion of the P-type electrode.

3h, the dielectric film on the surface of a portion of the P-type electrode 50 is etched away by using the yellow light process and the ICP etching process to expose a portion of the P-type electrode 50. The vertical projection of the exposed portion of the P-type electrode 50 completely overlaps with the exposed region of the P-type heavily doped layer 41.

S9, forming an N-type electrode on the second surface of the InP substrate.

Referring to FIG. 1 , the InP substrate 10 is thinned to 100 um-150 um by waxing, thinning and polishing processes, and then an N-type electrode 80 is fabricated on the second surface of the InP substrate 10 by an Ebeam metal evaporation process.

Compared with the prior art, the method for manufacturing a VCSEL device and the VCSEL device of the present invention use a nitrogen (hydrogen or air)/InP periodic structure that meets the Bragg reflection condition as an N-type DBR structure suitable for an InP substrate, providing a new idea for manufacturing a long-wavelength VCSEL device. The reflectivity of the N-type DBR structure to the wavelength light of the VCSEL device is greater than 99.9%, and the refractive index difference between the InP layer and the nitrogen (hydrogen or air) is fixed and easy to control.

The manufacturing method and VCSEL device of the present invention use a tunnel junction to manufacture the P-type electrode of the VCSEL device, which is simpler, more convenient and more efficient in terms of process. In addition, the Schottky structure formed between the metal material (GeAu/Ni/Au) of the P-type electrode and the P-type heavily doped layer can also limit the injection of the current injected into the VCSEL device, and can be used as a current limiting structure of the VCSEL device, having a current limiting effect.

It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims (11)

1. A method of fabricating a VCSEL device, comprising:

providing an InP substrate having opposed first and second surfaces, the first surface having first and second epitaxial regions;

growing an epitaxial structure on the first surface, wherein the epitaxial structure comprises a buffer layer, an N-type InGaAs/InP periodic structure, a resonant cavity, a P-type heavily doped layer and an N-type heavily doped layer which are sequentially grown;

Etching the epitaxial structure in the second epitaxial region to the buffer layer to expose a portion of the buffer layer or etching the epitaxial structure in the second epitaxial region to the substrate to expose a portion of the substrate;

Etching the InGaAs layer in the N-type InGaAs/InP periodic structure to remove part of the InGaAs layer from the second epitaxial region to the extending direction of the first epitaxial region so as to form a cavity;

growing an insulating epitaxial material in the second epitaxial region to form an insulating epitaxial structure so as to block the cavity in the InGaAs layer and support the InP layer;

Removing part of the N-type heavily doped layer to expose the P-type heavily doped layer;

Forming a P-type electrode on the exposed surface of the P-type heavily doped layer and part of the surface of the N-type heavily doped layer;

Forming a P-type DBR structure on the P-type electrode, the N-type heavily doped layer and the insulating epitaxial structure;

Etching the P-type DBR structure to expose a portion of the P-type electrode;

and forming an N-type electrode on the second surface of the InP substrate.

2. The method of fabricating a VCSEL device as claimed in claim 1, wherein an insulating epitaxial structure is grown in the second epitaxial region in a protective gas atmosphere to block cavities in the InGaAs layer;

the cavity is filled with the protective gas, and the protective gas and the InP layer are alternately arranged to form an N-type DBR structure.

3. The method of fabricating a VCSEL device as claimed in claim 2, wherein the shielding gas is selected from nitrogen or hydrogen; or alternatively

The shielding gas is selected from air.

4. The method of fabricating a VCSEL device as claimed in claim 1, wherein the insulating epitaxial structure is grown to be level with the epitaxial structure; and/or the number of the groups of groups,

The material of the insulating epitaxial structure is an InP material containing Fe.

5. The method of fabricating a VCSEL device as claimed in claim 1, wherein the InGaAs layer in the N-type InGaAs/InP periodic structure is chemically etched using a solution of H ₂SO₄:H₂O₂:H₂ O; and/or the number of the groups of groups,

The epitaxial structure and the insulating epitaxial structure are grown by metal organic chemical vapor deposition epitaxy or homoepitaxy.

6. The method of fabricating a VCSEL device as claimed in claim 1, wherein forming a P-type DBR structure on the P-type electrode, the N-type heavily doped layer and the insulating epitaxial structure comprises:

And alternately plating a first dielectric film layer with a first refractive index and a second dielectric film layer with a second refractive index on the P-type electrode, the N-type heavily doped layer and the insulating epitaxial structure, wherein the first refractive index is not equal to the second refractive index.

7. A VCSEL device, comprising:

an InP substrate having opposed first and second surfaces, the first surface having first and second epitaxial regions;

the N-type DBR structure is formed on the first epitaxial region and comprises InGaAs layers and InP layers which are sequentially and alternately arranged, a cavity is formed in the InGaAs layers, and protective gas is filled in the cavity;

The resonant cavity is formed on the N-type DBR structure;

The tunnel junction is formed on the resonant cavity and comprises a P-type heavily doped layer and an N-type heavily doped layer which are formed in sequence, and part of the P-type heavily doped layer is exposed out of the N-type heavily doped layer;

The P-type electrode is formed on the surface of the P-type heavily doped layer and extends to the surface of the N-type heavily doped layer;

an insulating epitaxial structure formed on the second epitaxial region of the first surface;

the P-type DBR structure is formed on the tunnel junction, part of the P-type electrode and the insulating epitaxial structure; and

And the N-type electrode is formed on the second surface of the InP substrate.

8. The VCSEL device as claimed in claim 7, further comprising a buffer layer formed on the first surface of the InP substrate; or alternatively

The InP substrate further comprises a buffer layer which is formed on the first epitaxial region of the first surface of the InP substrate.

9. The VCSEL device as claimed in claim 7, wherein the insulating epitaxial structure is arranged to follow the N-type DBR structure to block cavities in the InGaAs layer; and/or the number of the groups of groups,

The sum of the thicknesses of the N-type DBR structure, the resonant cavity and the tunnel junction is equal to the thickness of the insulating epitaxial structure; and/or the number of the groups of groups,

The material of the insulating epitaxial structure is an InP material containing Fe.

10. The VCSEL device as claimed in claim 7, wherein the shielding gas is selected from nitrogen or hydrogen; or alternatively

The shielding gas is selected from air.

11. The VCSEL device as claimed in claim 7, wherein the resonator cavity comprises an N-type InP layer, an N-type respective confinement layer, an active region, a P-type respective confinement layer and a P-type InP layer formed in sequence; and/or the number of the groups of groups,

The P-type DBR structure comprises a first dielectric film layer with a first refractive index and a second dielectric film layer with a second refractive index which are sequentially and alternately arranged, wherein the first refractive index is not equal to the second refractive index.