A vertical cavity surface emitting laser and its preparation method

Abstract

The present application discloses a vertical cavity surface emitting laser and a method for preparing the same, relating to the field of semiconductor device technology. The method for preparing the vertical cavity surface emitting laser of the present application comprises: sequentially forming an etch stop layer, a bottom reflector, a multi-quantum well layer, a top reflector, and a top connection layer on a substrate to form a device preform; dry etching is performed on one side of the device preform along the stacking direction until the bottom reflector is etched into the device preform; wet etching is performed on the bottom reflector until the etch stop layer is exposed; a negative electrode is formed on the exposed etch stop layer, and a positive electrode is formed on the top connection layer. The vertical cavity surface emitting laser and its preparation method provided by the present application can improve the consistency of the depth of the negative electrode connection structure, thereby improving the stability of the series resistance of the vertical cavity surface emitting laser.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor devices, and in particular to a vertical cavity surface emitting laser and a method for preparing the same. Background Art

[0002] Vertical Cavity Surface Emitting Lasers (VCSELs), also known as vertical resonant cavity surface-emitting lasers, differ from edge-emitting lasers, which are typically manufactured using a cut, independent chip process and emit laser light from the edge. VCSELs form a resonant cavity through a Bragg reflector, emitting light perpendicular to the surface of the semiconductor substrate. Compared to edge-emitting semiconductor lasers, VCSELs are immune to optical cavity surface damage and offer advantages such as low threshold current, dynamic single-mode operation, a small far-field divergence angle, a near-circular spot, a light direction perpendicular to the substrate surface, high fiber coupling efficiency, and ease of integration with microarrays. Therefore, VCSELs are widely used in optical interconnects, optical communications, optical signal processing, wavelength division multiplexing (WDM) fiber communications, neural networks, and computer chips. VCSEL-based applications such as 3D facial recognition, gesture recognition, iris recognition, autonomous driving, and lidar are all hot research topics.

[0003] Generally, a VCSEL consists of the following parts: substrate, N-DBR, multiple quantum well (MQW) active region, P-DBR, and ohmic contact layer. The N-DBR and P-DBR mirrors form the optical resonant cavity of the VCSEL, and the MQW active region is the carrier gain medium. By applying a voltage between the substrate and the ohmic contact layer to form electric pumping, the continuous lasing of the VCSEL laser is achieved. In the prior art, etching is usually started from the ohmic contact layer along the stacking direction, so that the contact surface between the substrate and the N-DBR is partially exposed, and a negative electrode is made on the exposed portion. However, due to the influence of the etching process, the depth of substrate etching cannot be accurately controlled, which makes the current flowing into the negative electrode pass through different lengths of the substrate, resulting in instability of the VCSEL series assembly. Summary of the Invention

[0004] The purpose of the present application is to provide a vertical cavity surface emitting laser and a preparation method thereof, which can improve the consistency of the depth of the negative electrode connection structure, thereby improving the stability of the series resistance of the vertical cavity surface emitting laser.

[0005] On the one hand, an embodiment of the present application provides a method for preparing a vertical cavity surface emitting laser, comprising: sequentially forming an etch stop layer, a bottom reflector, a multi-quantum well layer, a top reflector, and a top connection layer on a substrate to form a device preform; using dry etching to etch along the stacking direction on one side of the device preform until the bottom reflector is etched into the device preform; using wet etching to etch the bottom reflector until the etch stop layer is exposed; forming a negative electrode on the exposed etch stop layer, and forming a positive electrode on the top connection layer.

[0006] As an operative method, an etch stop layer, a bottom reflector, a multi-quantum well layer, a top reflector, and a top connection layer are sequentially formed on a substrate to form a device preform, comprising: depositing an etch stop material and a doping material on the substrate by a vapor deposition method to form an etch stop layer, wherein the etch stop layer is heavily doped to form an ohmic contact with the negative electrode, wherein the doping concentration is greater than or equal to 3e 19 / cm 3 .

[0007] As an practicable manner, the etching stop material is one of gallium indium phosphide, gallium arsenic phosphide, and aluminum gallium arsenic phosphide.

[0008] As an practicable manner, the etching solution used in the wet etching is a mixed solution of ammonium hydroxide and hydrogen peroxide.

[0009] As an practicable manner, the mass ratio of ammonium hydroxide to hydrogen peroxide in the etching solution is between 1:9 and 1:11.

[0010] As an practicable manner, the etching solution used in the wet etching is a mixed solution of phosphoric acid, hydrogen peroxide and water.

[0011] As an implementable method, forming a negative electrode on the exposed etch stop layer and forming a positive electrode on the top connection layer includes: depositing metal material on the top connection layer to form a metal layer, the material of the metal layer is the same as the material of the top connection layer, and the metal layer and the top connection layer form a positive electrode layer; using a mask to etch the positive electrode layer to form an electrode and a light output hole formed by the electrode.

[0012] As an practicable method, after forming a negative electrode on the exposed etch stop layer and a positive electrode on the top connection layer; the preparation method of the vertical cavity surface emitting laser also includes: the top reflector includes a plurality of stacked reflective layers, and ions are implanted into the peripheral area of ​​one of the reflective layers to form an oxide, and the oxide has high resistance to form a current limiting area in the top reflector.

[0013] As an practicable approach, the chemical formula of indium gallium phosphide is In x Ga 1-x In P, 0.56≤x≤0.71.

[0014] On the other hand, an embodiment of the present application provides a vertical cavity surface emitting laser, which is prepared using the above-mentioned method for preparing a vertical cavity surface emitting laser. The vertical cavity surface emitting laser includes a substrate and an etch stop layer, a bottom reflector, a multi-quantum well layer, a top reflector, and a positive electrode arranged on the top reflector in sequence. The area of ​​the substrate and the etch stop layer is larger than the area of ​​the bottom reflector so that a portion of the etch stop layer is exposed, and a negative electrode is arranged on the exposed etch stop layer.

[0015] The beneficial effects of the embodiments of the present application include:

[0016] The present application provides a method for fabricating a vertical cavity surface emitting laser (VCSEL), comprising: sequentially forming an etch stop layer, a bottom reflector, a multi-quantum well layer, a top reflector, and a top connection layer on a substrate to form a device preform; dry etching is performed on one side of the device preform along the stacking direction until the bottom reflector is etched into the substrate; wet etching is performed on the bottom reflector until the etch stop layer is exposed; and because the etching solution used in the wet etching has different etching rates for the material of the etch stop layer and the material of the bottom reflector, the etching solution stops etching at the top surface of the etch stop layer during the wet etching, resulting in the top surfaces of the etch stop layers having the same depth, forming a negative electrode on the exposed etch stop layer, and forming a positive electrode on the top connection layer. The negative electrode contacts the top surface of the etch stop layer, thereby ensuring that the depth of the negative electrode connection structure is the same, improving the consistency of the depth of the negative electrode connection structure, and thereby improving the stability of the series resistance of the VCSEL. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A flowchart of a method for preparing a vertical cavity surface emitting laser provided in an embodiment of the present application;

[0019] Figure 2 One of the state diagrams of a vertical cavity surface emitting laser provided in an embodiment of the present application;

[0020] Figure 3 The second state diagram of a vertical cavity surface emitting laser provided in an embodiment of the present application;

[0021] Figure 4The third state diagram of a vertical cavity surface emitting laser provided in an embodiment of the present application;

[0022] Figure 5 This is a fourth state diagram of a vertical cavity surface emitting laser provided in an embodiment of the present application;

[0023] Figure 6 A curve diagram showing the relationship between the etching solution ratio and the etching rate provided in an embodiment of the present application.

[0024] Icon: 100 - vertical cavity surface emitting laser; 110 - substrate; 120 - etch stop layer; 130 - bottom reflector; 140 - multi-quantum well layer; 150 - top reflector; 160 - top connection layer; 170 - positive electrode; 180 - negative electrode. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0028] This application provides a method for preparing a vertical cavity surface emitting laser 100, such as Figure 1 Shown, including:

[0029] S11: If Figure 2 As shown, an etch stop layer 120, a bottom reflector 130, a multi-quantum well layer 140, a top reflector 150 and a top connection layer 160 are sequentially formed on a substrate 110 to form a device preform;

[0030] Specifically, the specific process of forming an etch stop layer 120 on the substrate 110, forming a bottom reflector 130 on the etch stop layer, forming a multi-quantum well on the bottom reflector 130, forming a top reflector 150 on the multi-quantum well layer 140, and forming a top connection layer 160 on the top reflector 150 is not limited in the embodiments of the present application, as long as a uniform film layer can be formed on the substrate 110 in sequence. For example, it can be formed by sequential deposition.

[0031] The specific materials of each layer are not limited in the embodiment of the present application. The substrate 110 can be made of GaAs, doped GaAs, or other materials. The bottom reflector 130 and the top reflector 150 can be made of distributed Bragg reflectors. For example, the top reflector 150 uses a P-type distributed Bragg reflector, and the bottom reflector 130 uses an N-type distributed Bragg reflector. More specifically, the P-type distributed Bragg reflector can be made of C-doped Al x Ga 1-X As / GaAs alternately set up to form a stack, N-type distributed Bragg reflector uses Si-doped Al x Ga 1-X As / GaAs are alternately arranged to form a stack.

[0032] The multi-quantum well layer 140 may include a quantum well structure with multiple layers stacked together. The specific structure of each quantum well is not limited in the embodiments of the present application. For example, it may include a stack formed by alternating GaAs layers and AlGaAs layers located on the GaAs layers, or a stack formed by alternating GaAs layers and GaInAs layers located on the GaAs layers, or a stack formed by alternating GaAs layers and AlGaInAs layers located on the GaAs layers.

[0033] S12: Figure 3 As shown, dry etching is used to etch one side of the device preform along the stacking direction until the bottom reflector 130 is etched into the device preform.

[0034] The etching speed of dry etching is relatively fast. First, dry etching is used to etch into the bottom reflector 130 to complete the etching of most of the vertical structures of the device preform, which can increase the etching rate.

[0035] S13: If Figure 4 As shown, wet etching is used to etch the bottom reflector 130 until the etch stop layer 120 is exposed;

[0036] During wet etching, the etching solution is selected according to the specific material of the etch stop layer 120, so that the etching solution can etch the material of the bottom reflector 130, but will not etch the material of the etch stop layer 120, so that the etching stops at the upper surface of the etch stop layer 120. Since the upper surface of the etch stop layer 120 has a fixed depth, the etching has a fixed depth, thereby improving the consistency of the etching depth of multiple vertical cavity surface emitting lasers 100 in the process.

[0037] S14: Figure 5 As shown, a negative electrode 180 is formed on the exposed etch stop layer 120 , and a positive electrode 170 is formed on the top connection layer 160 .

[0038] A negative electrode 180 is formed on the etch stop layer 120 exposed after etching, and the negative electrode 180 contacts the upper surface of the etch stop layer 120. The upper surface of the etch stop layer 120 has a fixed depth, so that the negative electrode 180 has a fixed depth, thereby fixing the distance between the electrode and the multi-quantum well layer 140, thereby improving the stability of the series resistance of the multiple vertical cavity surface emitting lasers 100 in the support.

[0039] When the vertical cavity surface emitting laser 100 is working, the positive electrode 170 and the negative electrode 180 are respectively connected to the positive and negative electrodes of the pump power supply. The positive electrode of the power supply is applied to the multi-quantum well layer 140 through the top reflector 150, and the negative electrode of the power supply is applied to the multi-quantum well layer 140 through the etching stop layer 120 and the bottom reflector 130. The multi-quantum well layer 140 forms a standing wave under the action of the pump. The top reflector 150 and the bottom reflector 130 have a reflection efficiency higher than 99% respectively, so that the standing wave reflects back and forth between the relatively arranged top reflector 150 and the bottom reflector 130. During the reflection process, the energy of the photons in the standing wave gradually increases to form lasing, and finally is emitted by the top reflector 150 to form a laser.

[0040] The present application provides a method for preparing a vertical cavity surface emitting laser 100, comprising: sequentially forming an etch stop layer 120, a bottom reflector 130, a multi-quantum well layer 140, a top reflector 150, and a top connection layer 160 on a substrate 110 to form a device preform; dry etching is performed on one side of the device preform along the stacking direction until the bottom reflector 130 is etched into the device preform; wet etching is performed on the bottom reflector 130 until the etch stop layer 120 is exposed; and because the etching solution used in the wet etching has different etching rates for the material of the etch stop layer 120 and the material of the bottom reflector 130, during the wet etching, the etching solution stops etching when it etches to the upper surface of the etch stop layer 120, so that the upper surface of the etch stop layer 120 has the same depth, a negative electrode 180 is formed on the exposed etch stop layer 120, and a positive electrode 170 is formed on the top connection layer 160. The negative electrode 180 contacts the upper surface of the etch stop layer 120 , so that the depth of the connection structure of the negative electrode 180 is the same, thereby improving the consistency of the depth of the connection structure of the negative electrode 180 and further improving the stability of the series resistance of the vertical cavity surface emitting laser 100 .

[0041] Optionally, an etch stop layer 120, a bottom reflector 130, a multi-quantum well layer 140, a top reflector 150, and a top connection layer 160 are sequentially formed on the substrate 110 to form a device preform, comprising: depositing an etch stop material and a doping material on the substrate 110 by a vapor deposition method to form the etch stop layer 120, wherein the etch stop layer 120 is heavily doped to form an ohmic contact with the negative electrode 180, wherein the doping concentration is greater than or equal to 3e 19 / cm 3 .

[0042] The negative electrode 180 is connected to the bottom reflector 130 through the etch stop layer 120. The etch stop layer 120 is heavily doped, which introduces more carriers into the etch stop layer 120 and reduces the resistivity of the etch stop layer 120. The electrode is usually made of metal, and the etch stop layer 120 is made of semiconductor material, so that there is a lower barrier height between the electrode and the etch stop layer 120, which can stimulate the increase of the thermally excited part of the interface current between the electrode and the etch stop layer 120, thereby increasing the carriers flowing in the shell, so that the etch stop layer 120 forms an ohmic contact with the negative electrode 180, reducing the contact resistance between the negative electrode 180 and the stop etch layer. Specifically, the doping concentration is set to 3e 19 / cm 3 .

[0043] In one achievable manner of the embodiment of the present application, the etch stop material is one of gallium indium phosphide, gallium arsenic phosphide, and aluminum gallium arsenic phosphide.

[0044] Specifically, gallium indium phosphide, gallium arsenic phosphide, and aluminum gallium arsenic phosphide are configured differently from the material of the substrate 110 and the material of the bottom reflector 130. They are all compound semiconductor materials containing phosphorus. During wet etching, the etching solution only reacts with the material of the bottom reflector 130 to etch the bottom reflector 130. When the etching solution contacts the etch stop layer, it does not react with the material of the etch stop layer 120 to etch the etch stop layer 120, thereby stopping the etching at the upper surface of the etch stop layer 120. Specifically, the etching solution can react with the arsenic-containing semiconductor material in the bottom reflector 130, but does not react with the phosphorus-containing semiconductor material in the etch stop layer 120.

[0045] Optionally, the etching solution used in the wet etching is a mixed solution of ammonium hydroxide and hydrogen peroxide.

[0046] As alkaline etching solutions, ammonium hydroxide and hydrogen peroxide can react with the arsenic-containing semiconductor material in the bottom reflector 130 , but will not react with the phosphorus-containing semiconductor material in the etch stop layer 120 .

[0047] In one achievable manner of the embodiment of the present application, the mass ratio of ammonium hydroxide to hydrogen peroxide in the etching solution is between 1:9 and 1:11.

[0048] Those skilled in the art should know that the ratio of the various components in the etching solution will affect the etching rate. When the mass ratio of ammonium hydroxide to hydrogen peroxide is between 1:9 and 1:11, the etching solution has a higher etching rate for the bottom reflector 130, while the etching rate for the stop etching layer is zero.

[0049] Optionally, the etching solution used in the wet etching is a mixed solution of phosphoric acid, hydrogen peroxide and water.

[0050] The mixed solution of phosphoric acid, hydrogen peroxide and water is an acidic etching solution that can react with the arsenic-containing semiconductor material in the bottom reflector 130 , but will not react with the phosphorus-containing semiconductor material in the etch stop layer 120 .

[0051] The specific ratio of phosphoric acid, hydrogen peroxide and water is not limited in this application, and those skilled in the art can set it according to actual conditions, as long as the mixed solution of phosphoric acid, hydrogen peroxide and water can etch the bottom reflector 130 without etching the etch stop layer 120. For example, Figure 6 As shown in the figure, the relationship between the mixing ratio of phosphoric acid, hydrogen peroxide and water and the etching rate of indium gallium phosphide is plotted. Figure 6 It can be seen that when the value of X is 0 or 2, the etching rate of the mixed solution of phosphoric acid, hydrogen peroxide and water on gallium indium phosphide is zero. It should be noted that the etching rate is not only related to the solvent and ratio of the etching solution, but also to factors such as the temperature during etching. Therefore, Figure 6 The above description is merely an illustration of the ratio of phosphoric acid, hydrogen peroxide and water in a mixed solution, and does not limit the specific ratio. Those skilled in the art can adjust the ratio according to actual conditions.

[0052] In one possible implementation of the embodiment of the present application, forming the negative electrode 180 on the exposed etch stop layer 120 and forming the positive electrode 170 on the top connection layer 160 includes:

[0053] Depositing a metal material on the top connection layer 160 to form a metal layer. The material of the metal layer is the same as that of the top connection layer 160 . The metal layer and the top connection layer 160 form a positive electrode 170 layer.

[0054] The positive electrode 170 layer is etched using a mask to form an electrode and a light-emitting hole enclosed by the electrode.

[0055] Optionally, after forming a negative electrode 180 on the exposed etch stop layer 120 and forming a positive electrode 170 on the top connection layer 160 , the method for manufacturing the vertical cavity surface emitting laser 100 further includes:

[0056] The top reflector 150 includes a plurality of stacked reflective layers. Ions are implanted into the peripheral region of one of the reflective layers to form an oxide. The oxide has high resistance and forms a current confinement region in the top reflector 150 .

[0057] The positive electrode 170 applies voltage to the multi-quantum well layer 140 through the top reflector 150. Since the top reflector 150 is usually made of semiconductor materials, the current loss is relatively serious when the current flows through the top reflector 150. In order to reduce the current loss, the current is limited to a narrower area. Specifically, ions are implanted on the periphery of a reflective layer in the top reflector 150 to form an oxide. The oxide has a resistivity greater than that of the top reflector 150, so that the current flows through the unoxidized area of ​​the reflective layer, thereby reducing the current loss and improving the luminous efficiency of the vertical cavity surface emitting laser 100.

[0058] It should be noted that, in order to improve the light extraction efficiency of the laser, the unoxidized area can be set corresponding to the light extraction hole. The unoxidized area serves as a channel for current flow and also as a channel for light extraction.

[0059] In one possible implementation of the present invention, the chemical formula of indium gallium phosphide is In x Ga 1-x In P, 0.56≤x≤0.71.

[0060] Since the etch stop layer 120 is laid on the substrate 110, during the preparation process, the substrate 110 is usually made of GaAs. In order to match the lattice constant of the etch stop layer 120 with that of the substrate 110, the stress between the substrate 110 and the etch stop layer 120 is reduced to avoid the warping of the etch stop layer 120 film due to excessive stress between the two layers. When the substrate 110 is GaAs, the corresponding In x Ga 1-x In P, when 0.56≤x≤0.71, the lattice constant is closest to that of GaAs, thereby improving the film flatness of the stop etching layer.

[0061] The present application also discloses a vertical cavity surface emitting laser 100. Figure 5 As shown, the vertical cavity surface emitting laser 100 is prepared by the above-mentioned preparation method. The vertical cavity surface emitting laser 100 includes a substrate 110 and an etch stop layer 120, a bottom reflector 130, a multi-quantum well layer 140, a top reflector 150 and a positive electrode 170 arranged on the top reflector 150 in sequence. The area of ​​the substrate 110 and the etch stop layer 120 is larger than the area of ​​the bottom reflector 130 so that a portion of the etch stop layer 120 is exposed, and a negative electrode 180 is arranged on the exposed etch stop layer 120. The vertical cavity surface emitting laser 100 provided in the embodiment of the present application is provided with an etch stop layer 120 on the substrate 110, so that when etching downwards into the setting space for the negative electrode 180, etching can be performed to the upper surface of the etch stop layer 120. The negative electrode 180 is provided on the upper surface of the etch stop layer 120. Since the upper surface of the etch stop layer 120 has a fixed depth, the electrode has a fixed depth, thereby improving the consistency of the depth of the connection structure of the negative electrode 180, and further improving the stability of the series resistance of the vertical cavity surface emitting laser 100.

[0062] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for preparing a vertical cavity surface emitting laser, characterized in that: include: forming an etch stop layer, a bottom reflector, a multi-quantum well layer, a top reflector, and a top connection layer on the substrate in sequence to form a device preform; Dry etching is performed on one side of the device preform along the stacking direction until the bottom reflector is etched into the device preform; etching the bottom reflector by wet etching until the etch stop layer is exposed; forming a negative electrode on the exposed etch stop layer and forming a positive electrode on the top connection layer; The device preform is formed by sequentially forming an etch stop layer, a bottom reflector, a multi-quantum well layer, a top reflector, and a top connection layer on the substrate, comprising: An etch stop material and a doping material are deposited on the substrate by a vapor deposition method to form an etch stop layer, wherein the etch stop layer is heavily doped to form an ohmic contact with the negative electrode, wherein the doping concentration is greater than or equal to 3e 19 / cm 3 ; The etching stop material is one of gallium indium phosphide, gallium arsenic phosphide and aluminum gallium arsenic phosphide.

2. The method for preparing a vertical cavity surface emitting laser according to claim 1, wherein: The etching solution used in the wet etching is a mixed solution of ammonium hydroxide and hydrogen peroxide.

3. The method for preparing a vertical cavity surface emitting laser according to claim 2, wherein: The mass ratio of ammonium hydroxide to hydrogen peroxide in the etching solution is between 1:9 and 1:

11.

4. The method for preparing a vertical cavity surface emitting laser according to claim 1, wherein: The etching solution used in the wet etching is a mixed solution of phosphoric acid, hydrogen peroxide and water.

5. The method for preparing a vertical cavity surface emitting laser according to claim 1, wherein: Forming a negative electrode on the exposed etch stop layer and forming a positive electrode on the top connection layer comprises: Depositing a metal material on the top connection layer to form a metal layer, wherein the material of the metal layer is the same as that of the top connection layer, and the metal layer and the top connection layer form a positive electrode layer; The positive electrode layer is etched using a mask to form an electrode and a light-emitting hole enclosed by the electrode.

6. The method for preparing a vertical cavity surface emitting laser according to claim 1, wherein: After forming a negative electrode on the exposed etch stop layer and forming a positive electrode on the top connection layer; The method further includes: the top reflector includes a plurality of stacked reflective layers, and ion implantation is performed on a peripheral region of one of the reflective layers to form an oxide, wherein the oxide has high resistance to form a current confinement region in the top reflector.

7. The method for preparing a vertical cavity surface emitting laser according to claim 1, wherein: The chemical formula of indium gallium phosphide is In x Ga 1-x In P, 0.56≤x≤0.

71.

8. A vertical cavity surface emitting laser, characterized in that: The vertical cavity surface emitting laser is prepared using the preparation method of any one of claims 1 to 7, wherein the vertical cavity surface emitting laser includes a substrate and an etch stop layer, a bottom reflector, a multi-quantum well layer, a top reflector, and a positive electrode arranged on the top reflector in sequence, wherein the area of ​​the substrate and the etch stop layer is larger than the area of ​​the bottom reflector so that a portion of the etch stop layer is exposed, and a negative electrode is provided on the exposed etch stop layer.

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