Preparation method and application of high-stability VCSEL device

Abstract

The invention provides a preparation method and application of a high-stability VCSEL device, and relates to the technical field of VCSEL device preparation, and the preparation method comprises the steps: A, manufacturing an epitaxial wafer which comprises a substrate, an N-type DBR, an oxide layer, an active region, a P-type DBR and a contact layer which are stacked in sequence; when the epitaxial wafer is manufactured, the selection of a high-purity semiconductor material as a starting material is crucial, the introduction of impurities can be reduced from the source by the high-purity raw material, the condition that the impurities are diffused to an active region or form point defects in the subsequent growth process can be reduced by the low impurity concentration, and the stability of the device is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of VCSEL device preparation, and in particular to a preparation method and application of a high-stability VCSEL device. Background Art

[0002] As an important semiconductor optoelectronic device, vertical cavity surface emitting laser (VCSEL) has broad application prospects in optical communication, optical storage, optical sensing and laser radar. In the traditional VCSEL device preparation process, due to the complexity of the epitaxial wafer structure and the limitations of the preparation process, the stability and performance of the device are often difficult to reach the ideal state. In particular, in the key steps such as epitaxial wafer production, table etching, and electrode preparation, there are problems such as impurity introduction, surface damage, and incomplete oxidation, which seriously affect the reliability and service life of VCSEL devices. Therefore, we make improvements on this and propose a preparation method and application of high-stability VCSEL devices. Summary of the invention

[0003] The purpose of the present invention is to address the problems raised by the current background technology.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides a preparation method and application of a high-stability VCSEL device to improve the above-mentioned problem.

[0005] The specific application is as follows:

[0006] A method for preparing a high-stability VCSEL device, comprising:

[0007] A. Fabricating an epitaxial wafer, wherein the epitaxial wafer includes a substrate, an N-type DBR, an oxide layer, an active region, a P-type DBR and a contact layer stacked in sequence; performing atomic-level planarization on the surface of the substrate, specifically including:

[0008] Placing the substrate in a chemical mechanical polishing device, performing preliminary polishing using a polishing liquid containing nano-abrasives, wherein the abrasive concentration of the polishing liquid ranges from 10% to 15%, the polishing pressure ranges from 5000 to 8000 Pascals, and the polishing head speed ranges from 100 to 150 rpm, to reduce the surface roughness of the substrate to less than 5 nanometers;

[0009] The initially polished substrate is subjected to ion beam sputtering etching in an ultra-high vacuum environment to remove the residual microscopic undulations on the surface;

[0010] The substrate is placed in the chemical mechanical polishing equipment again, and fine polishing is performed using a finer polishing liquid, with an abrasive concentration ranging from 5% to 8%, a polishing pressure of 3000 to 5000 Pascals, and a polishing head speed of 80 to 120 rpm, so that the surface roughness of the substrate reaches less than 1 nanometer, providing an atomically flat surface for the subsequent growth of the epitaxial layer, improving the uniformity of the epitaxial layer growth and the crystal quality, thereby enhancing the stability of the VCSEL device;

[0011] B. preparing a mask pattern including a first mask and a second mask on the epitaxial wafer, wherein the first mask is used to define the shape and size of the first mesa, and the second mask is used to define the shape and size of the second mesa;

[0012] C. Through an etching process, a pattern is etched onto the epitaxial wafer using a first mask to form a first mesa, wherein the first mesa exposes the N-type DBR and the oxide layer; an ion implantation step is performed to adjust the electrical properties of the N-type DBR, and the specific operations are as follows:

[0013] Use an ion implanter to vertically implant ions into the N-type DBR region where the first table has been formed, and control the implantation angle deviation within ±2 degrees;

[0014] After the implantation, the epitaxial wafer is annealed at a high temperature ranging from 800 to 1000 degrees Celsius for 30 to 60 minutes to repair the lattice damage caused by the ion implantation, adjust the carrier concentration and mobility in the N-type DBR, and improve the electrical performance stability and reliability of the device;

[0015] D. Etch the pattern onto the VCSEL through a second mask to form a second mesa, where a portion of the P-type DBR is exposed; then perform a selective area doping enhancement process on the second mesa, the specific steps are as follows:

[0016] Using focused ion beam implantation technology, hydrogen ions are implanted into a specific area of ​​the second table, where the specific area is determined by a pre-designed graphic template;

[0017] After the implantation is completed, annealing treatment is carried out in a rapid thermal annealing device at a temperature of 900 degrees Celsius and an annealing time of 45 seconds, so that the ions can achieve precise doping distribution in the P-type DBR, improve the conductivity and carrier injection efficiency of the second mesa, and thus enhance the stability of the VCSEL device under high current injection;

[0018] E. Perform three-dimensional field effect modulation on the VCSEL device, specifically:

[0019] Micro-nano processing technology is used to build a three-dimensional electrode structure around the VCSEL device. The three-dimensional electrode structure includes a ring-shaped gate electrode made of gold. The gate is isolated from the epitaxial wafer by an insulating layer of silicon dioxide.

[0020] By applying different gate voltages, the electric field distribution in the active area is adjusted to achieve the restriction and guidance of carriers, thereby suppressing the excitation of high-order lateral modes and allowing only the fundamental mode to work; the gate voltage is controlled in the range of -5 to 5 volts, and the single-mode stability and beam quality of the VCSEL device are improved by modulating the electric field, thereby enhancing the overall stability of the device;

[0021] An N-type electrode is arranged on the N-type DBR, and a P-type electrode is arranged on the P-type DBR to form an ohmic contact, thereby completing the preparation of the VCSEL device.

[0022] The invention discloses an application of a method for preparing a high-stability VCSEL device, which is used to produce a high-stability VCSEL device.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] In the scheme of this application:

[0025] 1. When making epitaxial wafers, it is crucial to select high-purity semiconductor materials as starting materials. High-purity raw materials can reduce the introduction of impurities from the source. Low impurity concentration helps reduce the diffusion of impurities into the active area or the formation of point defects during the subsequent growth process, thereby improving the stability of the device;

[0026] 2. The surface of the substrate is flattened at the atomic level, first using chemical mechanical polishing equipment for preliminary polishing, then ion beam sputtering etching in an ultra-high vacuum environment, and finally fine polishing to make the surface roughness of the substrate less than 1 nanometer. This treatment method greatly improves the flatness of the substrate surface, provides an excellent foundation for the growth of subsequent layers, helps to reduce defects in the epitaxial layer growth process, and improves the overall quality and stability of the epitaxial wafer;

[0027] 3. After forming the first mesa, the N-type DBR is ion-implanted and annealed, which can accurately adjust the electrical properties of the N-type DBR, effectively repair the lattice damage caused by ion implantation, and achieve precise control of the carrier concentration and mobility in the N-type DBR, thereby optimizing the electrical properties of the device and improving the stability of the VCSEL device;

[0028] 4. The second mesa is subjected to a selective area doping enhancement process, where phosphorus ions are implanted into a specific area using focused ion beam implantation technology and annealed using a rapid thermal annealing device, which enables the ions to achieve precise doping distribution in the P-type DBR, which helps improve the electrical performance of the P-type DBR and, in turn, the performance of the entire VCSEL device;

[0029] 5. By constructing a three-dimensional electrode structure around the VCSEL device, using micro-nano processing technology to form a ring-shaped gate electrode, and adjusting the electric field distribution in the active area by applying different gate voltages, the carriers can be restricted and guided, allowing only the fundamental mode to work. This technology effectively suppresses the excitation of high-order lateral modes and improves the optical performance and stability of the device;

[0030] 6. In-situ monitoring and feedback control technologies are used throughout the entire preparation process, such as using a RHEED system to monitor epitaxial layer growth when preparing epitaxial wafers by molecular beam epitaxy, using a plasma monitoring system during etching, using an ellipsometry spectrometer during oxidation, and using a four-probe tester during electrode preparation. These technologies can monitor the key parameters of each process step in real time, and adjust the process parameters in a timely manner based on the monitoring results, ensuring the accuracy and consistency of the entire preparation process and improving the product yield and quality stability;

[0031] 7. The N-type electrode is set by an evaporation process, and the P-type electrode is set by a sputtering process. An ohmic contact is formed between the P-type electrode and the P-type DBR, ensuring a good electrical connection. At the same time, the P-type DBR adopts a multi-layer stepped structure, and the lateral area of ​​each layer gradually decreases from bottom to top. This structural design helps to optimize the electric field distribution and carrier transport inside the device, and further improve the performance and stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of a method for preparing a high-stability VCSEL device provided in the present application;

[0033] Figure 2 A schematic diagram of a method for preparing a high-stability VCSEL device provided in the present application. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme 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.

[0035] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions in the embodiments may be combined with each other.

[0036] 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, further definition and explanation thereof is not required in subsequent drawings.

[0037] Example 1, please refer to Figure 1-Figure 2 , a method for preparing a high-stability VCSEL device, comprising:

[0038] A. Fabricate epitaxial wafers, wherein the epitaxial wafers include a substrate, an N-type DBR, an oxide layer, an active region, a P-type DBR and a contact layer stacked in sequence; the substrate is used to support the entire structure and provide physical support for the device; the N-type DBR and the P-type DBR are like precise "light reflectors" that reflect light along a predetermined trajectory, greatly improving the utilization rate of light and ensuring that the light is fully oscillated and amplified in the active region; the active region is like a "luminous core" that continuously produces photons to achieve efficient generation and amplification of light; the contact layer is like a "conductive highway" that allows the electrode connection to be unimpeded, and each layer performs its duties and works closely together to ensure the stable and efficient operation of the device in all directions and achieve excellent optoelectronic device performance; the substrate surface is flattened at the atomic level, specifically including:

[0039] Placing the substrate in a chemical mechanical polishing device, performing preliminary polishing using a polishing liquid containing nano-abrasives, wherein the abrasive concentration of the polishing liquid ranges from 10% to 15%, the polishing pressure ranges from 5000 to 8000 Pascals, and the polishing head speed ranges from 100 to 150 rpm, to reduce the surface roughness of the substrate to less than 5 nanometers;

[0040] The initially polished substrate is subjected to ion beam sputtering etching in an ultra-high vacuum environment to remove the residual microscopic undulations on the surface;

[0041] The substrate is placed in the chemical mechanical polishing equipment again, and fine polishing is performed using a finer polishing liquid, with an abrasive concentration ranging from 5% to 8%, a polishing pressure of 3000 to 5000 Pascals, and a polishing head speed of 80 to 120 rpm, so that the surface roughness of the substrate reaches less than 1 nanometer, providing an atomically flat surface for the subsequent growth of the epitaxial layer, improving the uniformity of the epitaxial layer growth and the crystal quality, thereby enhancing the stability of the VCSEL device;

[0042] B. preparing a mask pattern including a first mask and a second mask on the epitaxial wafer, wherein the first mask is used to define the shape and size of the first mesa, and the second mask is used to define the shape and size of the second mesa;

[0043] C. Through an etching process, a pattern is etched onto the epitaxial wafer using a first mask to form a first mesa, wherein the first mesa exposes the N-type DBR and the oxide layer; an ion implantation step is performed to adjust the electrical properties of the N-type DBR, and the specific operations are as follows:

[0044] Use an ion implanter to vertically implant ions into the N-type DBR region where the first table has been formed, and control the implantation angle deviation within ±2 degrees;

[0045] After the implantation, the epitaxial wafer is annealed at a high temperature ranging from 800 to 1000 degrees Celsius for 30 to 60 minutes to repair the lattice damage caused by the ion implantation, adjust the carrier concentration and mobility in the N-type DBR, and improve the electrical performance stability and reliability of the device;

[0046] D. Etch the pattern onto the VCSEL through the second mask to form a second mesa, which exposes part of the P-type DBR. The setting of the second mesa exposes the P-type DBR area and provides space for the placement of the P-type electrode. When the P-type electrode and the P-type DBR are closely attached, the resistance is reduced, and the current can be injected in an orderly manner, which greatly optimizes the current injection path and reduces the unnecessary loss of energy during the transmission process. From the electrical performance level, it injects strong power into the efficient operation of the device and ensures its stable operation in a complex circuit environment; then perform a selective regional doping enhancement process on the second mesa. The specific steps are as follows:

[0047] Using focused ion beam implantation technology, hydrogen ions are implanted into a specific area of ​​the second table, where the specific area is determined by a pre-designed graphic template;

[0048] After the implantation is completed, annealing treatment is carried out in a rapid thermal annealing device at a temperature of 900 degrees Celsius and an annealing time of 45 seconds, so that the ions can achieve precise doping distribution in the P-type DBR, improve the conductivity and carrier injection efficiency of the second mesa, and thus enhance the stability of the VCSEL device under high current injection;

[0049] E. Perform three-dimensional field effect modulation on the VCSEL device, specifically:

[0050] Micro-nano processing technology is used to build a three-dimensional electrode structure around the VCSEL device. The three-dimensional electrode structure includes a ring-shaped gate electrode made of gold. The gate is isolated from the epitaxial wafer by an insulating layer of silicon dioxide.

[0051] By applying different gate voltages, the electric field distribution in the active area is adjusted to achieve the restriction and guidance of carriers, thereby suppressing the excitation of high-order lateral modes and allowing only the fundamental mode to work; the gate voltage is controlled in the range of -5 to 5 volts, and the single-mode stability and beam quality of the VCSEL device are improved by modulating the electric field, thereby enhancing the overall stability of the device;

[0052] An N-type electrode is set on the N-type DBR, and a P-type electrode is set on the P-type DBR to form an ohmic contact to complete the preparation of the VCSEL device. The successful construction of the ohmic contact is the key to the efficient operation of the device. It ensures a low-resistance connection between the electrode and the corresponding DBR layer like a superconductor. The current flows into the device at the contact interface, so that electrical energy can be converted into light energy with a higher efficiency, reducing the heat loss caused by the contact resistance and a series of thermal effect problems caused by it, such as thermal noise, thermal stress, etc., and the overall working efficiency of the device is improved.

[0053] Furthermore, in step A, the preparation of the epitaxial wafer includes: selecting semiconductor materials, such as gallium arsenide (GaAs), indium phosphide (I nP) or their alloys, and depositing them layer by layer to form a substrate, an N-type DBR, an oxide layer, an active region, a P-type DBR and a contact layer through molecular beam epitaxy (MBE), chemical vapor deposition (CVD) or atomic layer deposition (ALD) technology.

[0054] Further, step B comprises:

[0055] First, ensure that the surface of the epitaxial wafer (which has been stacked with substrate, N-type DBR, oxide layer, active area, P-type DBR and contact layer in sequence) is clean and free of impurities, and perform preliminary cleaning and drying treatment; use the spin coating method to evenly coat a layer of photoresist on the surface of the epitaxial wafer; pre-dry the epitaxial wafer coated with photoresist on a heating plate, and then expose it, place the exposed epitaxial wafer in a developer, remove the exposed photoresist part, and thus reveal the mask pattern. After completing the preparation of all mask patterns, thoroughly clean and dry the epitaxial wafer to remove all residual photoresist and other contaminants, and prepare for the subsequent etching steps. The strict surface pretreatment process ensures that the epitaxial wafer is in good initial condition and reduces the interference of impurities on subsequent photolithography, etching and other processes. Spin the photoresist and accurately control the drying, exposure and development steps to ensure high-precision replication of the mask pattern, provide a precise template for subsequent etching, and ensure the precise molding of the device microstructure. Thoroughly clean and remove residual photoresist, reduce pollution to etching equipment, and ensure process stability and device quality.

[0056] Furthermore, step C includes: placing the epitaxial wafer with the first mask pattern on the wafer carrier of the etching equipment, starting the etching equipment, starting the etching process, using reactive ion etching (RIE) or inductively coupled plasma (ICP) etching, and removing the material not covered by the mask by combining high-energy ion bombardment and chemical reaction. After the etching is completed, the epitaxial wafer is taken out of the etching equipment, and necessary cleaning and drying treatments are performed to remove residual etching products and contaminants. Reactive ion etching or inductively coupled plasma etching technology has the characteristics of high etching rate, high selectivity and high precision, and can accurately etch the required mesa structure according to the mask pattern, while minimizing damage to the mask and the underlying formed structure. The cleaning and drying treatment after etching can remove residual etching products, reduce their impact on subsequent processes, ensure stable device quality, and reduce problems such as short circuits and leakage caused by residues.

[0057] Furthermore, the P-type DBR portion adopts a multi-layer structure, and the lateral area of ​​each layer gradually decreases from bottom to top, forming a stepped structure to reduce the equivalent resistance and improve the heat dissipation performance. The stepped multi-layer P-type DBR structure reduces the resistance of the current transmission path from an electrical perspective, which is beneficial to improving the current injection efficiency and reducing power consumption; from a thermal perspective, the larger lateral area of ​​the lower layer is conducive to heat dissipation, improves the heat dissipation conditions of the device, reduces performance degradation caused by overheating, and improves the long-term working stability of the device.

[0058] Example 2, the preparation method and application of the high-stability VCSEL device provided in Example 1 are further optimized. Specifically, the N-type electrode is set by an evaporation process, the P-type electrode is set by a sputtering process, and an ohmic contact is formed between the P-type electrode and the P-type DBR to ensure good current injection efficiency. The N-type electrode is prepared by the evaporation process and the P-type electrode is prepared by the sputtering process. Compared with other methods, the thickness, uniformity and adhesion of the electrode can be better controlled. Combined with the realization of ohmic contact, the contact resistance between the electrode and the corresponding DBR layer is extremely low, the current can be smoothly injected, the energy loss is reduced, and the electro-optical conversion efficiency and working performance of the device are significantly improved.

[0059] Furthermore, in the process of preparing the VCSEL device, an in-situ monitoring and feedback control technology is used, specifically:

[0060] When preparing epitaxial wafers by molecular beam epitaxy, chemical vapor deposition or atomic layer deposition (step A), a reflection high energy electron diffraction (RHEED) system is used to monitor the growth of the epitaxial layer in real time. According to the intensity and periodicity of the RHEED diffraction pattern, the growth parameters such as beam intensity, gas flow rate and substrate temperature are adjusted to ensure the atomic layer thickness and quality of the epitaxial layer growth;

[0061] In steps C and D, a plasma monitoring system is used to monitor the density, ion energy and chemically active components of the etching plasma, and the etching power, gas flow rate and etching time are adjusted through feedback control to confirm the etching depth and sidewall verticality;

[0062] During step E, a four-probe tester is used to monitor the contact resistance of the electrode, and electrode deposition process parameters such as sputtering power or evaporation rate are adjusted according to the resistance value to ensure good ohmic contact;

[0063] Through this in-situ monitoring and feedback control technology, the high quality and high stability of VCSEL devices are guaranteed from every step of the preparation process.

[0064] Furthermore, a buffer layer is provided between the substrate and the N-type DBR. The material of the buffer layer is aluminum nitride (AlN) or gallium nitride (GaN), which is used to reduce the lattice mismatch between the substrate and the N-type DBR, reduce the dislocation density, improve the quality of the epitaxial wafer, provide an excellent foundation for the high-quality growth of subsequent functional layers, and ensure the high performance and stability of the device.

[0065] Example 3, application of a method for preparing a high-stability VCSEL device, used to produce a high-stability VCSEL device.

[0066] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0067] Obviously, the embodiments described above are only some embodiments of the present invention, rather than all embodiments. The preferred embodiments of the present invention are given in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to replace some of the technical features therein with equivalents. Any equivalent structure made using the contents of the specification and drawings of the present invention, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present invention.

Claims

1. A method for preparing a high-stability VCSEL device, characterized in that: include: A. manufacturing an epitaxial wafer, wherein the epitaxial wafer comprises a substrate, an N-type DBR, an oxide layer, an active region, a P-type DBR and a contact layer stacked in sequence; The substrate is subjected to atomic-level flattening treatment, including: Placing the substrate in a chemical mechanical polishing device, performing preliminary polishing using a polishing liquid containing nano-abrasives, wherein the abrasive concentration of the polishing liquid ranges from 10% to 15%, the polishing pressure ranges from 5000 to 8000 Pascals, and the polishing head speed ranges from 100 to 150 rpm, to reduce the surface roughness of the substrate to less than 5 nanometers; The initially polished substrate is subjected to ion beam sputtering etching in an ultra-high vacuum environment to remove the residual microscopic undulations on the surface; The substrate is placed in the chemical mechanical polishing equipment again, and fine polishing is performed using a finer polishing liquid, with an abrasive concentration ranging from 5% to 8%, a polishing pressure of 3000 to 5000 Pascals, and a polishing head speed of 80 to 120 rpm, so that the surface roughness of the substrate reaches less than 1 nanometer; B. preparing a mask pattern including a first mask and a second mask on the epitaxial wafer, wherein the first mask is used to define the shape and size of the first mesa, and the second mask is used to define the shape and size of the second mesa; C. Through an etching process, a pattern is etched onto the epitaxial wafer using a first mask to form a first mesa, wherein the first mesa exposes the N-type DBR and the oxide layer; an ion implantation step is performed to adjust the electrical properties of the N-type DBR, and the specific operations are as follows: Use an ion implanter to vertically implant ions into the N-type DBR region where the first table has been formed, and control the implantation angle deviation within ±2 degrees; After the implantation, the epitaxial wafer is annealed at a high temperature ranging from 800 to 1000 degrees Celsius for 30 to 60 minutes to repair the lattice damage caused by the ion implantation and to adjust the carrier concentration and mobility in the N-type DBR. D. Etch the pattern onto the VCSEL through a second mask to form a second mesa, where a portion of the P-type DBR is exposed; then perform a selective area doping enhancement process on the second mesa, the specific steps are as follows: Using focused ion beam implantation technology, hydrogen ions are implanted into a specific area of ​​the second table, where the specific area is determined by a pre-designed graphic template; After the implantation is completed, annealing is carried out in a rapid thermal annealing device at a temperature of 900 degrees Celsius for 45 seconds to achieve precise doping distribution of ions in the P-type DBR; E. Perform three-dimensional field effect modulation on the VCSEL device, specifically: Micro-nano processing technology is used to build a three-dimensional electrode structure around the VCSEL device. The three-dimensional electrode structure includes a ring-shaped gate electrode made of gold. The gate is isolated from the epitaxial wafer by an insulating layer of silicon dioxide. By applying different gate voltages, the electric field distribution in the active region is adjusted to achieve carrier confinement and guidance, thereby suppressing the excitation of high-order lateral modes and allowing only the fundamental mode to work; An N-type electrode is arranged on the N-type DBR, and a P-type electrode is arranged on the P-type DBR to form an ohmic contact, thereby completing the preparation of the VCSEL device.

2. The method for preparing a high-stability VCSEL device according to claim 1, characterized in that: In step A, the production of the epitaxial wafer includes: selecting semiconductor materials, and depositing layer by layer to form a substrate, an N-type DBR, an oxide layer, an active area, a P-type DBR and a contact layer through molecular beam epitaxy, chemical vapor deposition or atomic layer deposition technology.

3. The method for preparing a high-stability VCSEL device according to claim 2, characterized in that: Step B includes: First, ensure that the surface of the epitaxial wafer is clean and free of impurities, and perform preliminary cleaning and drying. Use the spin coating method to evenly coat a layer of photoresist on the surface of the epitaxial wafer. Pre-dry the epitaxial wafer coated with photoresist on a heating plate, and then expose it. Place the exposed epitaxial wafer in a developer to remove the exposed photoresist portion to reveal the mask pattern. After completing the preparation of all mask patterns, thoroughly clean and dry the epitaxial wafer to remove all residual photoresist and other contaminants in preparation for the subsequent etching step.

4. The method for preparing a high-stability VCSEL device according to claim 3, characterized in that: Step C includes: placing the epitaxial wafer with the first mask pattern on the wafer carrier of the etching equipment, starting the etching equipment, starting the etching process, using reactive ion etching or inductively coupled plasma etching, and removing the material not covered by the mask by combining high-energy ion bombardment and chemical reaction. After the etching is completed, the epitaxial wafer is removed from the etching equipment and necessary cleaning and drying treatment is performed to remove residual etching products and contaminants.

5. The method for preparing a high-stability VCSEL device according to claim 4, characterized in that: The P-type DBR part adopts a multi-layer structure, and the lateral area of ​​each layer gradually decreases from bottom to top, forming a stepped structure.

6. The method for preparing a high-stability VCSEL device according to claim 5, characterized in that: The N-type electrode is disposed through an evaporation process, the P-type electrode is disposed through a sputtering process, and an ohmic contact is formed between the P-type electrode and the P-type DBR.

7. The method for preparing a high-stability VCSEL device according to claim 6, characterized in that: In the process of preparing VCSEL devices, in-situ monitoring and feedback control technology is used, specifically: When preparing epitaxial wafers by molecular beam epitaxy, chemical vapor deposition or atomic layer deposition (step A), a reflection high energy electron diffraction (RHEED) system is used to monitor the growth of the epitaxial layer in real time, and the growth parameters are adjusted according to the intensity and periodicity of the RHEED diffraction pattern.

8. The method for preparing a high-stability VCSEL device according to claim 7, characterized in that: In steps C and D, a plasma monitoring system is used to monitor the density, ion energy and chemically active components of the etching plasma, and the etching power, gas flow rate and etching time are adjusted through feedback control to confirm the etching depth and sidewall verticality; When performing step E, a four-probe tester is used to monitor the contact resistance of the electrode, and the electrode deposition process parameters are adjusted according to the resistance value.

9. The method for preparing a high-stability VCSEL device according to claim 8, characterized in that: A buffer layer is arranged between the substrate and the N-type DBR.

10. An application of the method for preparing a high-stability VCSEL device according to claim 9, characterized in that: Used to produce high stability VCSEL devices.

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