Preparation method of multi-layer VCSEL chip

Abstract

The present application discloses a method for preparing a multilayer VCSEL chip, the preparation method comprising: performing electron beam lithography on a single crystal silicon substrate to obtain a substrate having a predetermined nano-patterned structure; introducing an aminosilane gas source into the substrate surface to obtain a substrate covered with a monomolecular layer; sequentially depositing an aluminum oxide material and a silicon nitride material on the substrate covered with a monomolecular layer to obtain a photonic crystal layer with a high reflectivity; evaporating and condensing the semiconductor material onto the photonic crystal layer based on laser pulse technology to form a quantum well layer with a predetermined thickness; in a nitrogen environment, reorganizing the material atoms in the quantum well layer according to a predetermined lattice arrangement to obtain an optimized quantum well layer; depositing a metal electrode on the optimized quantum well layer to form an electrical contact layer to obtain a multilayer VCSEL chip. The present application improves the performance and production controllability of the VCSEL chip, solves the problems of crystal defects, surface roughness, and stress mismatch existing in the prior art, and has significant technical advantages.

Description

Technical Field

[0001] The present application relates to the technical field of chip preparation, and in particular to a method for preparing a multi-layer VCSEL chip. Background Art

[0002] Vertical Cavity Surface Emitting Laser (VCSEL) is a laser device widely used in optical communication, sensing, laser printing and other fields due to its high efficiency and miniaturization. The key performance of VCSEL is subject to the design of its optical structure and the selection of materials. At present, the manufacturing of VCSEL chips is mainly epitaxial growth technology, such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE). These methods grow quantum well structure, reflector layer and electrode contact layer on a suitable substrate.

[0003] In practical applications, in the process of growing the quantum well layer in the prior art, the optical and electrical properties of VCSEL are easily affected due to problems such as crystal defects, surface roughness and stress mismatch, which directly limits the improvement of its luminous efficiency, threshold current and device life. Lattice mismatch and stress accumulation in the epitaxial growth process often lead to a decrease in film quality, thereby affecting the optical properties of the reflector layer and the luminous efficiency of the quantum well, making the existing process have certain limitations in improving device performance. In particular, in the design of the high-reflectivity photonic crystal layer, how to balance the high quality of the reflector layer and the effective luminescence of the quantum well layer has become an important challenge for VCSEL chip manufacturing technology. Summary of the invention

[0004] The purpose of the present application is to provide a method for preparing a multi-layer VCSEL chip, so as to solve the technical problem that the existing VCSEL chip manufacturing technology cannot take into account both the high quality of the reflector layer and the effective luminescence of the quantum well layer.

[0005] To achieve this goal, this application adopts the following technical solutions:

[0006] A method for preparing a multi-layer VCSEL chip, comprising:

[0007] Performing electron beam lithography on a single crystal silicon substrate to obtain a substrate having a predetermined nano-patterned structure;

[0008] Introducing an aminosilane gas source into the surface of the substrate so that the substrate and the aminosilane gas source react with each other to obtain a substrate covered with a monomolecular layer;

[0009] Depositing aluminum oxide material and silicon nitride material in sequence on the substrate covered with the monomolecular layer to obtain a photonic crystal layer with high reflectivity;

[0010] Based on laser pulse technology, semiconductor material is evaporated and condensed onto the photonic crystal layer to form a quantum well layer with a predetermined thickness;

[0011] In a nitrogen environment, the material atoms in the quantum well layer are reorganized according to a predetermined lattice arrangement to obtain an optimized quantum well layer;

[0012] A metal electrode is deposited on the optimized quantum well layer to form an electric contact layer, thereby obtaining the multi-layer VCSEL chip.

[0013] Furthermore, the aluminum oxide material is any one or a combination of aluminum oxide or aluminum nitride oxide, and the silicon nitride material is any one or a combination of silicon nitride or silicon nitride.

[0014] Furthermore, the semiconductor material is any one of indium phosphide, gallium arsenide and gallium nitride, or a combination of several of them.

[0015] Furthermore, the step of performing electron beam lithography on the single crystal silicon substrate to obtain a substrate having a predetermined nano-patterned structure comprises:

[0016] The surface of the single crystal silicon substrate is subjected to ultrasonic cleaning treatment based on deionized water and ethanol solution to obtain a clean substrate surface;

[0017] Applying electron beam photoresist to the cleaned substrate surface based on spin coating, wherein the coating of the electron beam photoresist is 300 nanometers;

[0018] The substrate coated with the photoresist is subjected to a soft drying process, wherein the temperature is set to 80-90° C. and the drying is continued for 25-30 seconds to obtain a dried substrate;

[0019] Exposing the dried substrate using an electron beam exposure device, wherein the exposure dose is set to 480-500 μC / cm² and the exposure time is set to 5-6 seconds to form a predetermined nano-patterned structure;

[0020] The exposed substrate is developed with a developer to dissolve the unexposed portion of the photoresist, thereby obtaining a substrate with a predetermined nano-patterned structure on the surface of the substrate.

[0021] Furthermore, the step of introducing an aminosilane gas source into the surface of the substrate so that the substrate and the aminosilane gas source react with each other to obtain a substrate covered with a monomolecular layer comprises:

[0022] The substrate surface is subjected to substrate surface electron beam irradiation treatment, wherein the irradiation energy is set to 50-60 keV and the irradiation dose is set to 10-15 µC / cm², so that negatively charged active sites are generated on the substrate surface;

[0023] placing the substrate into a reaction chamber and introducing aminosilane gas, so that the aminosilane gas reacts with the active sites to form a monomolecular layer;

[0024] Introducing nitrogen into the reaction chamber for gas exchange, wherein the nitrogen flow rate is 50-60 sccm, maintaining the chamber pressure at 50-60 Pa, and continuing to purge for 30-35 minutes;

[0025] The reaction product between the aminosilane molecule and the substrate surface is detected by spectroscopy to obtain the formation of the monolayer, and the thickness of the monolayer is adjusted based on the formation to obtain a substrate covered with the monolayer.

[0026] Furthermore, the step of using spectroscopy to detect the reaction product between the aminosilane molecules and the substrate surface to obtain the formation of a monolayer, and adjusting the thickness of the monolayer based on the formation to obtain a substrate covered with a monolayer includes:

[0027] Performing Fourier transform infrared spectroscopy analysis on the substrate to detect the chemical bonding between the substrate surface and the aminosilane to obtain spectral data, wherein the spectral data includes characteristic peak data of molecular vibration after the substrate surface reaction;

[0028] The spectrum baseline is corrected based on the polynomial fitting method to obtain the corrected characteristic peak data;

[0029] Performing peak extraction on the corrected characteristic peak data, decomposing multiple overlapping peaks in the spectral data to obtain characteristic peaks, and obtaining the maximum absorption value of each characteristic peak;

[0030] Fitting the relationship between the maximum absorption value and the coverage of the monolayer on the substrate surface to obtain a quantitative model, and calculating the thickness change value of the monolayer based on the quantitative model;

[0031] Determine whether the thickness change value is greater than a preset target value. If it is less than, increase the aminosilane gas flow rate or reaction time to increase the deposition amount of the molecular layer; if it is greater than, reduce the aminosilane gas flow rate or reaction time to reduce the deposition amount of the molecular layer; until the thickness of the monomolecular layer reaches the preset target value, a substrate covered with a monomolecular layer is obtained.

[0032] Furthermore, the step of sequentially depositing an aluminum oxide material and a silicon nitride material on a substrate covered with a monomolecular layer to obtain a photonic crystal layer with high reflectivity comprises:

[0033] Placing the substrate covered with the monomolecular layer in a vacuum chamber, and performing vacuum deposition treatment on the substrate based on a high-purity aluminum target at a current density of 2-3A / cm² to form an aluminum oxide film;

[0034] During the vacuum deposition process, the reflectivity of the aluminum oxide film is continuously tested, and if the reflectivity does not reach a preset reflectivity value, the rate and time of vacuum deposition are adjusted until the reflectivity of the aluminum oxide film reaches a preset reflectivity value, thereby forming an aluminum oxide layer;

[0035] Depositing silicon nitride material on the surface of the aluminum oxide layer to form a silicon nitride film layer, wherein the deposition conditions are to set the flow ratio of nitrogen gas to silicon source gas to 3:1, the temperature to 340-350° C., and the silicon nitride deposition rate to 10-15 nm per minute;

[0036] The stress distribution of the silicon nitride film layer is obtained based on Raman spectroscopy, and the stress of the silicon nitride film layer is regulated according to the stress distribution result until the stress distribution of the silicon nitride film layer meets the preset requirements to form a photonic crystal layer with high reflectivity.

[0037] Furthermore, the step of evaporating and condensing the semiconductor material onto the photonic crystal layer based on the laser pulse technology to form a quantum well layer with a predetermined thickness includes:

[0038] Performing optimization calculation on laser pulse parameters of the photonic crystal layer to obtain calculated pulse parameters, wherein the pulse parameters include pulse energy, frequency and laser wavelength;

[0039] According to the pulse parameters, the output power and pulse frequency of the laser source are obtained and adjusted to obtain parameter settings of the laser pulse stream, and the laser pulse stream is adjusted based on the parameter settings;

[0040] irradiating the adjusted laser pulse flow onto the surface of the photonic crystal layer, and based on the laser pulse technology, the semiconductor material is evaporated by instantaneous heating and rapidly condensed on the substrate surface to form a preliminary quantum well layer;

[0041] The number of laser pulse irradiations and the energy of a single pulse are controlled based on a preset thickness, so that the thickness of the preliminary quantum well layer gradually increases and recrystallizes during a plurality of pulse iterative deposition processes, thereby forming a quantum well layer with a predetermined thickness.

[0042] Furthermore, the step of reorganizing the material atoms in the quantum well layer according to a predetermined lattice arrangement under a nitrogen environment to obtain an optimized quantum well layer includes:

[0043] Characterize the crystal structure of the quantum well layer, obtain potential lattice defects and stress distribution in the quantum well layer, and obtain defect data and lattice parameters of the quantum well layer;

[0044] Simulating the lattice arrangement of the quantum well layer based on the defect data and the lattice parameters to obtain a lattice reorganization algorithm for the quantum well layer;

[0045] Placing the quantum well layer in a nitrogen environment, and controlling the nitrogen partial pressure and temperature based on the lattice recombination algorithm to obtain a primary quantum well layer;

[0046] Performing ion beam implantation on the primary quantum well layer based on fast ion beam technology to optimize the lattice arrangement of the primary quantum well layer to obtain an intermediate quantum well layer;

[0047] The intermediate quantum well layer is subjected to secondary characterization to obtain an optimized quantum well layer.

[0048] Furthermore, the step of depositing a metal electrode on the optimized quantum well layer to form an electrical contact layer to obtain the multi-layer VCSEL chip includes:

[0049] Performing an optical interference test on the surface of the optimized quantum well layer to obtain an interference pattern, and obtaining optical uniformity information of the surface of the quantum well layer based on the distribution of interference fringes in the interference pattern;

[0050] Selecting a corresponding metal electrode material based on the optical uniformity information, and depositing the metal electrode material on the surface of the optimized quantum well layer to form a metal thin film layer;

[0051] Depositing a thin passivation layer on the metal film layer based on atomic layer deposition technology to form the electrical contact layer;

[0052] The metal film layer and the thin passivation layer are patterned based on photolithography technology to obtain the multi-layer VCSEL chip.

[0053] Compared with the prior art, this application has the following beneficial effects:

[0054] The preparation method of the multilayer VCSEL chip of the present application obtains a substrate with a predetermined nano-patterned structure by performing electron beam lithography on a single crystal silicon substrate, which can reduce the influence of surface roughness and crystal defects, thereby improving the deposition quality of the photonic crystal layer. An aminosilane gas source is used to react with the substrate surface to obtain a substrate covered with a monolayer of molecules. The semiconductor material is evaporated and condensed onto the photonic crystal layer based on laser pulse technology to form a quantum well layer with a predetermined thickness. The laser pulse technology can accurately control the deposition rate and thickness of the material, avoiding the problem of film quality degradation caused by lattice mismatch and stress accumulation in traditional epitaxial growth technology, and effectively reducing the influence of crystal defects on the performance of the quantum well layer. By atomically reorganizing the quantum well layer material in a nitrogen environment, the lattice arrangement of the quantum well layer is optimized, so that it has higher optical efficiency and lower threshold current, and metal electrodes are deposited on the optimized quantum well layer to form an electrical contact layer, which provides a stable electrical contact for the VCSEL chip and ensures its long-term stable operation. In general, the present invention effectively improves the performance and production controllability of VCSEL chips by optimizing substrate processing, material deposition and quantum well layer optimization processes, solves problems such as crystal defects, surface roughness and stress mismatch in the prior art, and has significant technical advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0056] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0057] Figure 1 Schematic diagram of the overall steps of the method for preparing a multi-layer VCSEL chip;

[0058] Figure 2 A schematic diagram of the steps of an embodiment of a method for preparing a multi-layer VCSEL chip;

[0059] Figure 3 FIG. 1 is a schematic diagram of the steps of another embodiment of a method for preparing a multi-layer VCSEL chip. DETAILED DESCRIPTION

[0060] In order to make the purpose, features, and advantages of the invention of this application more obvious and easy to understand, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the embodiments described below are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0061] In the description of the present application, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0062] The technical solution of the present application is further explained below with reference to the accompanying drawings and through specific implementation methods.

[0063] refer to Figures 1 to 3 The present application provides a method for preparing a multi-layer VCSEL chip, comprising:

[0064] S1: performing electron beam lithography on a single crystal silicon substrate to obtain a substrate having a predetermined nano-patterned structure;

[0065] In step S1, a high-precision nanostructure is formed on the surface of the substrate using electron beam lithography. Before electron beam lithography, the monocrystalline silicon substrate is pretreated, including cleaning and surface treatment, to remove any possible contaminants, such as organic matter or particles, to ensure that the photolithographic pattern can be accurately formed on the substrate surface without impurities, and a uniform layer of photoresist is coated on the substrate surface. This layer of photoresist will serve as a photosensitive material for electron beam lithography, and the predetermined nano pattern is exposed to the photoresist by electron beam scanning. Due to the high energy of the electron beam, it can induce a chemical reaction on the surface of the photoresist, decomposing or cross-linking the photoresist in the exposed area. The chemical changes in the exposed area make the photoresist in these areas dissolve or insoluble in the developer, thereby forming the desired pattern structure. The advantage of electron beam lithography is its extremely high resolution, which can accurately form patterns on the nanometer scale, which is crucial for the manufacture of VCSEL chips, because the performance of VCSEL is directly related to the accuracy of its microstructure. After the exposure is completed, the photoresist in the exposed area is removed by the developer, while the unexposed part remains unchanged, and the desired nano pattern is finally formed on the substrate surface. After the development process, the substrate is usually hard-baked to further fix the photoresist pattern and increase its durability. After these steps, a photolithography pattern with a predetermined structure will be formed on the surface of the single crystal silicon substrate.

[0066] S2: introducing an aminosilane gas source into the surface of the substrate, so that the substrate and the aminosilane gas source react with each other to obtain a substrate covered with a monomolecular layer;

[0067] In step S2, aminosilane is a type of chemical reagent used for surface modification and material functionalization. It has an amino (-NH2) functional group and a silane group (-SiH3), which enables it to react chemically with the silicon oxide (SiO2) surface of the substrate through the silane group to form a chemical bond and stably adhere to the substrate surface. In the specific operation, the surface of the single crystal silicon substrate is cleaned, and the cleaned substrate is placed in a specific reaction chamber, and an aminosilane gas source is introduced under controlled atmosphere conditions. The aminosilane gas reacts with the surface of the substrate to form a monolayer covering the substrate. The thickness of this monolayer is generally at the nanometer level, between 1-3 nanometers, depending on factors such as the concentration of the aminosilane gas source, the introduction time, and the temperature. During the reaction, the silane group of the aminosilane reacts with the surface silicon oxide of the substrate to form a stable silicon oxide silicon bond, firmly fixing the aminosilane molecules on the surface of the substrate. At the same time, the amino functional group (-NH2) will be exposed on the surface of the substrate, which makes the surface of the substrate hydrophilic and has a certain chemical activity, which can enhance the adhesion between the substrate and subsequent materials, especially the bonding force with metal materials or other functional layers, forming a chemically functional monolayer.

[0068] S3: depositing an aluminum oxide material and a silicon nitride material sequentially on the substrate covered with the monomolecular layer to obtain a photonic crystal layer with high reflectivity;

[0069] In step S3, chemical vapor deposition (CVD) or physical vapor deposition (PVD) technology is used. For aluminum oxide materials, aluminum source gas (such as aluminum trifluoride or aluminum chloride) can be used to react with oxygen source gas (such as oxygen or ozone) in a reaction chamber during its deposition process to form an aluminum oxide film. After the aluminum oxide material is deposited, silicon nitride material is deposited. Silicon nitride is a material used for photonic crystal layers. Its advantages lie in its good mechanical properties and thermal stability. In addition, it can provide appropriate optical reflection properties for the chip. The deposition process of silicon nitride material can also use CVD or PVD technology to form a silicon nitride film by using silicon source gas (such as silicon tetrachloride) and nitrogen source gas (such as ammonia). The alternating deposition of aluminum oxide and silicon nitride materials forms a photonic crystal layer with high reflectivity to form an optical resonant cavity to provide a reflector for the VCSEL (vertical cavity surface emitting laser) structure. The alternating layers of these materials have excellent reflection properties, which can effectively reflect the laser beam and confine it to the effective emission area of ​​the chip. The photonic crystal layer formed by the alternating deposition of aluminum oxide and silicon nitride not only helps to improve the efficiency of the VCSEL chip, but also reduces energy loss when the laser is working and improves the overall performance.

[0070] S4: evaporating and condensing semiconductor material onto the photonic crystal layer based on laser pulse technology to form a quantum well layer with a predetermined thickness;

[0071] In step S4, a high-energy pulse generated by a high-energy laser beam is used to heat the semiconductor material to its evaporation temperature to form vapor, which condenses into a thin film during the cooling process. The evaporation and condensation processes can be controlled by controlling the energy, duration and frequency of the laser pulse. The quantum well layer is composed of semiconductor materials such as nitrides or arsenides. With the help of laser pulse technology, the deposition conditions can be accurately adjusted to avoid uneven thickness or local defects, thereby ensuring the film quality of the quantum well layer on the photonic crystal layer. In addition to thickness control, laser pulse technology can also produce specific atomic structures or thin film crystal forms during material deposition. After the semiconductor material in the quantum well layer is evaporated by laser pulses, an extremely thin layered structure will be formed on the surface of the photonic crystal layer. These layered structures will determine the energy level distribution and exciton behavior of the electrons, thereby affecting the optical performance of the VCSEL chip.

[0072] S5: Under a nitrogen environment, reorganizing the material atoms in the quantum well layer according to a predetermined lattice arrangement to obtain an optimized quantum well layer;

[0073] In step S5, the quantum well layer is composed of semiconductor materials such as nitride, arsenide or phosphide. The quantum well structure allows carriers (electrons and holes) to be confined in a thin layer and generate radiation through quantum effects. The atomic recombination of the material is carried out in a nitrogen environment. The role of nitrogen as an inert gas is mainly to prevent oxidation reactions that may be triggered under high temperature conditions, and it can also control the heat treatment process of the material to a certain extent. In this environment, the semiconductor material in the quantum well layer will be heated under appropriate temperature conditions, activating the movement between atoms, so that the atoms can be rearranged according to their lattice structure, thereby achieving lattice optimization. The semiconductor material in the quantum well layer needs to meet certain lattice matching conditions to ensure the effective recombination of electrons and holes, thereby improving the luminous efficiency of the laser. By controlling the temperature and nitrogen environment, the material can be rearranged during the heat treatment process, repairing defects and making the lattice structure more perfect, reducing the dislocation and defects of the material, and optimizing the performance of the quantum well.

[0074] S6: depositing a metal electrode on the optimized quantum well layer to form an electrical contact layer to obtain the multi-layer VCSEL chip;

[0075] In step S6, a metal electrode is deposited on the optimized quantum well layer to form an electrical contact layer, thereby completing the electrical connection and ensuring the normal operation of the VCSEL chip. A metal electrode is deposited on the surface of the optimized quantum well layer to form an electrical contact layer. The metal electrode not only needs to have good conductivity, but also needs to have good contact with the quantum well layer to ensure that the current can be smoothly conducted to the quantum well layer and stimulate laser radiation. Optional metal materials include gold (Au), aluminum (Al), titanium (Ti), etc. These metals have good conductivity, and can form a stable film during the deposition process, and have good interface properties with semiconductor materials. Sputtering deposition or evaporation deposition technology is used to deposit metal electrodes. Sputtering deposition is a method of bombarding a metal target with high-energy particles (usually argon ions) to sputter metal atoms from the target and then deposit them on the surface of the quantum well layer. This method can form a thin film uniformly on the entire surface and is suitable for deposition requirements over a large area. Another commonly used method is electron beam evaporation deposition, which heats the metal material to a high temperature, evaporates it and condenses it on the surface of the quantum well layer to form the required electrode layer. Electron beam evaporation can provide a high deposition rate and high deposition quality, and is suitable for metal layers that require high precision. After the metal electrode is deposited, annealing (heat treatment) is performed to improve the interface quality between the metal electrode and the semiconductor material by heating, thereby reducing the contact resistance and enhancing the current transmission efficiency. Annealing can promote the diffusion between metal and semiconductor materials, thereby improving the bonding force between the metal electrode and the quantum well layer, and ensuring the stability and conductivity of the electrode layer. By depositing metal electrodes on the optimized quantum well layer and forming an electrical contact layer, the electrical connection of the VCSEL chip is completed, and finally a prepared multi-layer VCSEL chip is obtained.

[0076] In one embodiment, the aluminum oxide material is any one or a combination of aluminum oxide or aluminum nitride oxide, the silicon nitride material is any one or a combination of silicon nitride or silicon nitride, and the semiconductor material is any one or a combination of indium phosphide, gallium arsenide and gallium nitride.

[0077] In this embodiment, the aluminum oxide material can be selected from a combination of aluminum oxide or aluminum oxide nitride. These materials have excellent optical properties and high reflectivity, which are helpful to construct an efficient photonic crystal layer and improve the light reflection and laser output efficiency of the VCSEL chip. In addition, aluminum oxide nitride also has good thermal stability and mechanical strength, which helps to improve the long-term stability and reliability of the chip. As part of the photonic crystal layer, silicon nitride or silicon nitride not only has good optical properties, but also can effectively improve the anti-reflection performance of the VCSEL chip and reduce surface scattering, thereby optimizing the laser output quality of the chip. The excellent electrical insulation of silicon nitride material can also enhance the overall performance of the chip, reduce current leakage, and increase the energy efficiency of the chip. Indium phosphide, gallium arsenide and gallium nitride, as semiconductor materials, have good electrical and optical properties in the VCSEL structure and can effectively support the laser emission of the quantum well layer. By selecting a combination of these materials according to specific needs, while ensuring the optoelectronic performance, the laser wavelength, efficiency and stability of the VCSEL chip can also be adjusted and optimized.

[0078] In one embodiment, the step of performing electron beam lithography on a single crystal silicon substrate to obtain a substrate having a predetermined nano-patterned structure includes:

[0079] The surface of the single crystal silicon substrate is subjected to ultrasonic cleaning treatment based on deionized water and ethanol solution to obtain a clean substrate surface;

[0080] Applying electron beam photoresist to the cleaned substrate surface based on spin coating, wherein the coating of the electron beam photoresist is 300 nanometers;

[0081] The substrate coated with the photoresist is subjected to a soft drying process, wherein the temperature is set to 80-90° C. and the drying is continued for 25-30 seconds to obtain a dried substrate;

[0082] Exposing the dried substrate using an electron beam exposure device, wherein the exposure dose is set to 480-500 μC / cm² and the exposure time is set to 5-6 seconds to form a predetermined nano-patterned structure;

[0083] The exposed substrate is developed with a developer to dissolve the unexposed portion of the photoresist, thereby obtaining a substrate with a predetermined nano-patterned structure on the surface of the substrate.

[0084] In this embodiment, the monocrystalline silicon substrate is ultrasonically cleaned based on deionized water and ethanol solution. Ultrasonic cleaning uses the mechanical force of high-frequency sound waves to remove dirt, particles and any potential impurities on the substrate surface from the substrate surface. The mixed use of deionized water and ethanol solution can effectively remove water-soluble and oil-soluble impurities, ensuring that the substrate surface reaches a high degree of cleanliness. On the clean substrate surface, electron beam photoresist is coated on it using spin coating. Spin coating is a coating technology used in photolithography. By rotating the substrate at high speed, the photoresist forms a uniform film on the substrate surface. The photoresist thickness is 300 nanometers. The substrate after applying the photoresist is soft-dried, and a temperature range of 80 to 90°C is set, and the drying time is 25 to 30 seconds. The main purpose of soft drying is to remove the solvent in the photoresist, so that it becomes stable and easy to expose. After soft drying, the substrate enters the electron beam exposure stage, and the predetermined electron beam is exposed to the photoresist by the electron beam exposure equipment. The exposure dose is set to 480 to 500 μC / cm², and the exposure time is 5 to 6 seconds. At this stage, the unexposed part of the photoresist remains in its original state, while the exposed part undergoes chemical changes, thus forming a clear pattern in the subsequent development step. After exposure, the substrate enters the development process step, and the exposed substrate is developed with a developer to remove the unexposed photoresist. The developer dissolves the unexposed part of the photoresist, leaving the exposed area, and finally forming the desired nano-patterned structure.

[0085] refer to Figure 2 In one embodiment, the step of introducing an aminosilane gas source into the surface of the substrate so that the substrate and the aminosilane gas source react with each other to obtain a substrate covered with a monomolecular layer comprises:

[0086] S21: performing electron beam irradiation treatment on the surface of the substrate, wherein the irradiation energy is set to 50-60keV and the irradiation dose is set to 10-15 µC / cm², so that negatively charged active sites are generated on the surface of the substrate;

[0087] S22: placing the substrate into a reaction chamber and introducing aminosilane gas, so that the aminosilane gas reacts with the active sites to form a monomolecular layer;

[0088] S23: introducing nitrogen gas into the reaction chamber for gas exchange, wherein the nitrogen gas flow rate is 50-60 sccm, the chamber pressure is maintained at 50-60 Pa, and the purge is continued for 30-35 minutes;

[0089] S24: using a spectroscopic method to detect the reaction products between the aminosilane molecules and the substrate surface to obtain the formation of a monolayer, and adjusting the thickness of the monolayer based on the formation to obtain a substrate covered with the monolayer.

[0090] In this embodiment, the surface of the substrate is subjected to electron beam irradiation treatment to improve the activity of the substrate surface so that it can react with the aminosilane gas source to form a monolayer. Electron beam irradiation treatment uses an accelerated electron beam to irradiate high-energy electrons to the surface of the substrate. By setting the irradiation energy between 50 and 60 keV and adjusting the irradiation dose to 10 to 15 µC / cm², the surface of the substrate will be excited and negatively charged active sites will be generated. The substrate after electron beam irradiation treatment is placed in a reaction chamber, and aminosilane gas is then introduced into the reaction chamber. Aminosilane gas molecules react with negatively charged active sites on the surface of the substrate to form a chemically bonded monolayer on the surface of the substrate. The strong interaction between the active functional groups of the aminosilane molecules and the surface sites enables the aminosilane molecules to be uniformly deposited on the surface of the substrate and form a monolayer. Aminosilane molecules have good controllability in the thickness of the molecular layer, and the construction of this monolayer is to provide a uniform and stable chemical environment on the surface of the substrate. After the formation of the aminosilane molecular layer is completed, nitrogen gas exchange is performed. Nitrogen enters the reaction chamber at a flow rate of 50-60 sccm, and the pressure in the chamber is maintained between 50 and 60 Pa. During this gas exchange process, nitrogen can not only help remove by-products produced during the reaction, but also maintain the stability of the reaction chamber and prevent other undesirable reactions from occurring. By continuously purging for 30-35 minutes, nitrogen can effectively remove residual gas in the reaction chamber, ensuring that the formation of the aminosilane monolayer is completed under ideal environmental conditions. In order to detect the formation of the monolayer and adjust it, spectroscopy is used for analysis. Spectroscopy can determine the quality and uniformity of the monolayer by detecting the products after the aminosilane molecules react with the substrate surface. By analyzing the spectral characteristics of the reaction products, it can be determined whether the aminosilane has been fully reacted and whether the thickness of the monolayer meets expectations. If the spectral analysis shows that the thickness of the monolayer does not meet the design requirements, the gas flow rate, reaction time or irradiation conditions can be further adjusted according to the spectral results to optimize the formation process of the monolayer.

[0091] refer to Figure 3 In one embodiment, the step of using spectroscopy to detect the reaction product between the aminosilane molecules and the substrate surface to obtain the formation of a monolayer, and adjusting the thickness of the monolayer based on the formation to obtain a substrate covered with a monolayer includes:

[0092] S241: Performing Fourier transform infrared spectroscopy analysis on the substrate to detect the chemical bonding between the substrate surface and the aminosilane, and obtaining spectral data, wherein the spectral data includes characteristic peak data of molecular vibration after the substrate surface reaction;

[0093] S242: Correcting the spectrum baseline based on a polynomial fitting method to obtain corrected characteristic peak data;

[0094] S243: performing peak extraction on the corrected characteristic peak data, decomposing multiple overlapping peaks in the spectral data to obtain characteristic peaks, and obtaining the maximum absorption value of each characteristic peak;

[0095] S244: fitting the relationship between the maximum absorption value and the coverage of the monolayer on the substrate surface to obtain a quantitative model, and calculating the thickness change value of the monolayer based on the quantitative model;

[0096] S245: Determine whether the thickness change value is greater than a preset target value. If so, increase the aminosilane gas flow rate or reaction time to increase the deposition amount of the molecular layer. If so, reduce the aminosilane gas flow rate or reaction time to reduce the deposition amount of the molecular layer. This is performed until the thickness of the monomolecular layer reaches the preset target value to obtain a substrate covered with a monomolecular layer.

[0097] In this embodiment, Fourier transform infrared spectroscopy (FTIR) technology can provide information about chemical bonding by measuring the absorption of the sample at different infrared wavelengths. In this process, after the substrate surface reacts with the aminosilane gas, new chemical bonds are formed, and these bonds will appear as specific absorption peaks in the infrared spectrum, corresponding to the vibration mode inside the molecule. Therefore, by analyzing the infrared spectrum data of the substrate surface by FTIR, relevant information about the chemical bonding between the aminosilane molecules and the substrate surface after the reaction can be obtained, such as whether the aminosilane molecules are successfully bound to the surface and the degree of reaction. The baseline of the spectral data is corrected by the polynomial fitting method through the acquired spectral data. Since the spectral baseline may be offset due to factors such as equipment or experimental conditions during the infrared spectrum measurement, this offset may affect the accuracy of the analysis results. By using the polynomial fitting method to correct the spectral baseline, the actual spectral data is more accurate, and the corrected data can more truly reflect the reaction between the substrate surface and the aminosilane. For the corrected spectral data, multiple overlapping spectral peaks are decomposed to obtain each characteristic peak, and the maximum absorption value of each characteristic peak is extracted therefrom. This process is to extract the key information that best represents the reaction between aminosilane and the substrate surface from the complex spectral data. Since multiple absorption peaks may overlap in spectral analysis, the peak extraction technology deconstructs these overlapping peaks through mathematical models to obtain the specific absorption information of each characteristic peak. The maximum absorption value of each characteristic peak reflects the strength of a specific chemical bond or vibration mode. After obtaining the maximum absorption value of these characteristic peaks, the relationship between the absorption value and the coverage of the monolayer on the substrate surface is fitted by constructing a quantitative model. The coverage of the monolayer on the substrate surface usually refers to the degree of uniform deposition of aminosilane molecules on the surface. By establishing a quantitative relationship between the absorption value and the coverage, the thickness of the monolayer can be calculated. Specifically, by calculating these maximum absorption values, the thickness change of the monolayer can be predicted, and the deposition of the molecular layer can be grasped in real time. The reaction conditions are adjusted by comparing the calculated thickness change value with the target value. If the calculated thickness change value is less than the target value, the deposition amount of the monolayer is insufficient. At this time, the deposition amount can be increased by increasing the aminosilane gas flow rate or extending the reaction time, thereby thickening the monolayer. On the contrary, if the thickness change value is greater than the target value, it means that the deposited monolayer is too thick. At this time, the deposition amount can be reduced by reducing the aminosilane gas flow rate or shortening the reaction time to ensure that the monolayer thickness does not exceed the expected range. Through such adjustments, it can be ensured that the thickness of the monolayer accurately reaches the preset target value, and a uniform and stable covering layer is obtained.

[0098] In one embodiment, the step of sequentially depositing an aluminum oxide material and a silicon nitride material on a substrate covered with a monomolecular layer to obtain a photonic crystal layer with high reflectivity comprises:

[0099] Placing the substrate covered with the monomolecular layer in a vacuum chamber, and performing vacuum deposition treatment on the substrate based on a high-purity aluminum target at a current density of 2-3A / cm² to form an aluminum oxide film;

[0100] During the vacuum deposition process, the reflectivity of the aluminum oxide film is continuously tested, and if the reflectivity does not reach a preset reflectivity value, the rate and time of vacuum deposition are adjusted until the reflectivity of the aluminum oxide film reaches a preset reflectivity value, thereby forming an aluminum oxide layer;

[0101] Depositing silicon nitride material on the surface of the aluminum oxide layer to form a silicon nitride film layer, wherein the deposition conditions are to set the flow ratio of nitrogen gas to silicon source gas to 3:1, the temperature to 340-350° C., and the silicon nitride deposition rate to 10-15 nm per minute;

[0102] The stress distribution of the silicon nitride film layer is obtained based on Raman spectroscopy, and the stress of the silicon nitride film layer is regulated according to the stress distribution result until the stress distribution of the silicon nitride film layer meets the preset requirements to form a photonic crystal layer with high reflectivity.

[0103] In this embodiment, a substrate covered with a monolayer is placed in a vacuum chamber, and a high-purity aluminum target is used as a target material to deposit an aluminum oxide material onto the substrate surface by vacuum deposition technology. In order to ensure that the deposited aluminum oxide film has sufficient quality and performance, the current density of the deposition process is set between 2 and 3 A / cm². This current density range can ensure that the aluminum material can be effectively deposited and form a uniform film layer. During the deposition of the aluminum oxide film, the reflectivity of the film is continuously monitored. During the deposition of the aluminum oxide film, if the reflectivity does not reach the preset value, the rate and time of vacuum deposition are automatically adjusted to ensure that the quality of the film meets the requirements. This adjustment involves increasing the deposition time or adjusting the deposition rate to improve the optical reflectivity of the film. The aluminum oxide layer is completed only when the reflectivity meets the requirements. Silicon nitride material is deposited on the surface of the aluminum oxide layer to form a silicon nitride film layer. When depositing the silicon nitride film layer, special attention should be paid to the flow ratio of nitrogen and silicon source gas. In this embodiment, the flow ratio of nitrogen and silicon source gas is set to 3:1. Too much or too little nitrogen and silicon source gas ratio will affect the quality of silicon nitride film. During the deposition process, the temperature of silicon nitride is controlled between 340 and 350 ° C. Too low temperature may lead to too slow deposition rate and poor film quality; while too high temperature may increase the volatility of the material and affect the deposition uniformity. The deposition rate of silicon nitride film is controlled at 10-15 nm per minute. This rate ensures that silicon nitride material can be uniformly and stably deposited on the surface of aluminum oxide layer. The stress distribution of silicon nitride film is detected by Raman spectroscopy. Raman spectroscopy is a material characterization technology that can detect the stress state inside the film. By obtaining the stress distribution information of silicon nitride film, it is possible to accurately determine whether the film has excessive internal stress. If this stress is not regulated, it may cause the film to warp or crack, seriously affecting the performance of VCSEL chip. If it is detected that the stress distribution of the silicon nitride film does not meet the preset requirements, it is regulated according to the magnitude of the stress, and the stress distribution of the film is optimized by adjusting the deposition conditions, changing the gas flow, temperature or deposition rate and other parameters. This process ensures that the silicon nitride film performs at its best in the entire photonic crystal structure, avoids potential problems caused by uneven stress, and ensures that the final high-reflectivity photonic crystal layer can exhibit excellent optical performance during the operation of the VCSEL chip.

[0104] In one embodiment, the step of evaporating and condensing semiconductor material onto the photonic crystal layer based on laser pulse technology to form a quantum well layer with a predetermined thickness includes:

[0105] Performing optimization calculation on laser pulse parameters of the photonic crystal layer to obtain calculated pulse parameters, wherein the pulse parameters include pulse energy, frequency and laser wavelength;

[0106] According to the pulse parameters, the output power and pulse frequency of the laser source are obtained and adjusted to obtain parameter settings of the laser pulse stream, and the laser pulse stream is adjusted based on the parameter settings;

[0107] irradiating the adjusted laser pulse flow onto the surface of the photonic crystal layer, and based on the laser pulse technology, the semiconductor material is evaporated by instantaneous heating and rapidly condensed on the substrate surface to form a preliminary quantum well layer;

[0108] The number of laser pulse irradiations and the energy of a single pulse are controlled based on a preset thickness, so that the thickness of the preliminary quantum well layer gradually increases and recrystallizes during a plurality of pulse iterative deposition processes, thereby forming a quantum well layer with a predetermined thickness.

[0109] In this embodiment, the laser pulse parameters of the photonic crystal layer are optimized and calculated based on the laser pulse technology. By calculating these parameters, the energy, frequency and wavelength of the laser pulse can be determined. The pulse energy determines the instantaneous heating effect of the laser irradiation on the substrate, the pulse frequency determines the emission rate of the laser pulse, and different laser wavelengths can produce different interactions with the absorption characteristics of the material. The choice of wavelength needs to match the optical properties of the semiconductor material to achieve the best evaporation effect. After obtaining the pulse parameters after the optimization calculation, the output power and pulse frequency of the laser source are adjusted according to these parameters. By adjusting these parameters, the effect of each laser pulse on the substrate can be controlled so that the evaporation process reaches an ideal state, thereby ensuring the quality of the quantum well layer. After adjusting the laser pulse flow, it is irradiated to the surface of the photonic crystal layer, so that the semiconductor material can evaporate by instantaneous heating and quickly condense on the surface of the substrate. The effect of the laser pulse is relatively short and concentrated in a very small area. This high energy density laser irradiation will cause the semiconductor material to reach the evaporation point in a very short time, and then quickly condense on the surface of the substrate to form a preliminary quantum well layer. Based on the preset quantum well layer thickness requirements, the number of irradiations of the laser pulse and the energy of each pulse are further controlled. The thickness of the quantum well layer determines its electrical and optical properties. By adjusting the number of laser pulses and the energy of a single pulse, the thickness of the quantum well layer can be gradually increased during multiple pulse iterations. Each laser pulse deposits a thin layer of semiconductor material on the substrate surface, which will continue to recrystallize during the subsequent deposition process, eventually forming a uniform quantum well layer with a predetermined thickness. In this process, since the action time of each pulse is very short, the evaporated semiconductor material will quickly cool and condense on the substrate surface, which helps to form a layered structure. As the pulses continue to superimpose, the thickness of the quantum well layer gradually increases, and the formation of each layer of film will further optimize the crystal structure between the layers and enhance the performance of the quantum well. The recrystallization process helps to eliminate defects in the film and ensure the quality of the quantum well layer. By continuously optimizing these deposition parameters, the final quantum well layer has the desired thickness and crystal structure.

[0110] In one embodiment, the step of reorganizing the material atoms in the quantum well layer according to a predetermined lattice arrangement under a nitrogen environment to obtain an optimized quantum well layer includes:

[0111] Characterize the crystal structure of the quantum well layer, obtain potential lattice defects and stress distribution in the quantum well layer, and obtain defect data and lattice parameters of the quantum well layer;

[0112] Simulating the lattice arrangement of the quantum well layer based on the defect data and the lattice parameters to obtain a lattice reorganization algorithm for the quantum well layer;

[0113] Placing the quantum well layer in a nitrogen environment, and controlling the nitrogen partial pressure and temperature based on the lattice recombination algorithm to obtain a primary quantum well layer;

[0114] Performing ion beam implantation on the primary quantum well layer based on fast ion beam technology to optimize the lattice arrangement of the primary quantum well layer to obtain an intermediate quantum well layer;

[0115] The intermediate quantum well layer is subjected to secondary characterization to obtain an optimized quantum well layer.

[0116] In this embodiment, in the process of optimizing the quantum well layer, its crystal structure is characterized, the potential lattice defects and stress distribution in the quantum well layer are analyzed, and information about defect data and lattice parameters is obtained. Through characterization, imperfect structures in the lattice, such as defects, dislocations or stress concentration areas, can be detected, and the lattice arrangement of the quantum well layer is simulated based on these data. This simulation process aims to design a lattice reorganization algorithm to guide how to adjust the atomic arrangement of the quantum well layer to achieve an optimized state. The role of simulation is to foresee the impact of different lattice arrangements on material properties. Through simulation, the change trend of the lattice under different conditions (such as different temperatures, atmospheres, etc.) can be predicted, and then an optimal reorganization strategy can be determined. The quantum well layer is placed in a nitrogen environment to perform a lattice reorganization process. In a nitrogen environment, the lattice arrangement of the quantum well layer can be adjusted by controlling the partial pressure and temperature of the gas. According to the lattice reorganization algorithm simulated in the early stage, the partial pressure and temperature of the nitrogen are adjusted, and the material atoms in the quantum well layer can be guided to reorganize according to the predetermined lattice arrangement, improve the original defect structure, and form an optimized primary quantum well layer. With the help of temperature and atmosphere control, the atoms in the quantum well layer can be rearranged under thermal excitation, thereby eliminating some stresses and defects and improving the crystal quality. The primary quantum well layer is ion-beam implanted using fast ion beam technology to further optimize the lattice arrangement. Ion beam implantation is a technology that changes the material structure by bombarding the surface of the material with high-energy ions. In this embodiment, the ion beam implantation technology is used to excite the atoms of the material in the primary quantum well layer, accelerate and implant specific types of ions (such as nitrogen ions or argon ions) into the surface of the quantum well layer. Through ion beam implantation, the defects in the primary quantum well layer are further eliminated, and the arrangement of the lattice is more orderly, thereby optimizing the optical and electrical properties of the quantum well layer. After the ion beam implantation is completed, the intermediate quantum well layer is secondary characterized to confirm the optimization effect and obtain the final state of the quantum well layer. The secondary characterization can provide detailed information about the crystal structure of the intermediate quantum well layer, including the tiny defects that may still exist and the arrangement of the overall lattice. This step is crucial to verify whether the optimization is successful. If the secondary characterization shows that there are still problems with the lattice structure of the intermediate quantum well layer, it may be necessary to perform lattice restructuring or ion beam implantation again until the desired optimization effect is achieved.

[0117] In one embodiment, the step of depositing a metal electrode on the optimized quantum well layer to form an electrical contact layer to obtain the multi-layer VCSEL chip includes:

[0118] Performing an optical interference test on the surface of the optimized quantum well layer to obtain an interference pattern, and obtaining optical uniformity information of the surface of the quantum well layer based on the distribution of interference fringes in the interference pattern;

[0119] Selecting a corresponding metal electrode material based on the optical uniformity information, and depositing the metal electrode material on the surface of the optimized quantum well layer to form a metal thin film layer;

[0120] Depositing a thin passivation layer on the metal film layer based on atomic layer deposition technology to form the electrical contact layer;

[0121] The metal film layer and the thin passivation layer are patterned based on photolithography technology to obtain the multi-layer VCSEL chip.

[0122] In this embodiment, an optical interference test is performed on the surface of the quantum well layer, and the optical uniformity of the surface of the quantum well layer is detected by utilizing the interference phenomenon of light. When light is irradiated to the surface of the quantum well layer, the reflected light will produce interference fringes because the surface morphology of different regions may be different. The distribution of these fringes can reveal the uniformity of the surface microstructure, and by analyzing these interference patterns, information about the optical uniformity of the surface can be obtained. After obtaining the optical uniformity information, the corresponding metal electrode material is selected, and the metal electrode material is deposited on the surface of the optimized quantum well layer to form a metal film layer. For example, the optical uniformity information includes the surface flatness. When the surface is flat and the optical uniformity is good, a material with higher electrical conductivity, such as gold, silver or copper, can be selected, because these metals have strong electrical conductivity and can ensure efficient conduction of current. The deposition method of the metal film can adopt evaporation deposition, sputtering deposition or other vapor deposition techniques. Through these methods, the metal material can be evenly covered on the surface of the quantum well layer to form a continuous metal layer, which plays the role of connecting the quantum well layer and the external circuit, so that the current can be effectively transmitted to the quantum well layer to stimulate its luminescence. Atomic layer deposition is a precise thin film deposition technology that deposits only one atomic layer of material at a time by alternately injecting gaseous precursor chemicals into the reaction chamber, thereby forming a very uniform film with controllable thickness. In this embodiment, atomic layer deposition is used to deposit a thin passivation layer on the metal film layer. This passivation layer can be made of nitride or oxide materials, such as silicon nitride (SiNx) or aluminum oxide (Al2O3), which can effectively prevent the metal layer from reacting with oxygen or moisture in the environment, thereby improving the stability and long-term service life of the metal electrode. The passivation layer can also prevent the metal electrode from corroding under high temperature or other harsh conditions, which helps to maintain the efficient operation of the VCSEL chip. After the passivation layer is deposited, it is patterned by photolithography technology, and a photosensitive material (such as photoresist) is coated on the surface of the metal film layer and the passivation layer. Then, through the exposure and development process, the designed pattern is transferred to the photoresist layer, and then the unexposed part is removed by chemical corrosion or dry etching, so as to form a precise electrode pattern on the metal film layer and the passivation layer. The electrical contact pattern of the metal film layer and the passivation layer formed the final electrical contact layer, and finally formed the electrical contact layer of the VCSEL chip.

[0123] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a multi-layer VCSEL chip, characterized in that: include: Performing electron beam lithography on a single crystal silicon substrate to obtain a substrate having a predetermined nano-patterned structure; Introducing an aminosilane gas source into the surface of the substrate so that the substrate and the aminosilane gas source react with each other to obtain a substrate covered with a monomolecular layer; Depositing aluminum oxide material and silicon nitride material in sequence on the substrate covered with the monomolecular layer to obtain a photonic crystal layer with high reflectivity; Based on laser pulse technology, semiconductor material is evaporated and condensed onto the photonic crystal layer to form a quantum well layer with a predetermined thickness, specifically comprising: Performing optimization calculation on laser pulse parameters of the photonic crystal layer to obtain calculated pulse parameters, wherein the pulse parameters include pulse energy, frequency and laser wavelength; According to the pulse parameters, the output power and pulse frequency of the laser source are obtained and adjusted to obtain parameter settings of the laser pulse stream, and the laser pulse stream is adjusted based on the parameter settings; irradiating the adjusted laser pulse flow onto the surface of the photonic crystal layer, and based on the laser pulse technology, the semiconductor material is evaporated by instantaneous heating and rapidly condensed on the substrate surface to form a preliminary quantum well layer; Controlling the number of laser pulse irradiations and the energy of a single pulse based on a preset thickness, so that the thickness of the preliminary quantum well layer gradually increases and recrystallizes during a plurality of pulse iterative deposition processes, thereby forming a quantum well layer with a predetermined thickness; In a nitrogen environment, the material atoms in the quantum well layer are reorganized according to a predetermined lattice arrangement to obtain an optimized quantum well layer, specifically comprising: Characterize the crystal structure of the quantum well layer, obtain potential lattice defects and stress distribution in the quantum well layer, and obtain defect data and lattice parameters of the quantum well layer; The lattice arrangement of the quantum well layer is simulated based on the defect data and the lattice parameters to obtain a lattice reorganization algorithm for the quantum well layer, wherein the lattice reorganization algorithm is used to guide the adjustment of the atomic arrangement of the quantum well layer to achieve an optimized state. The role of the simulation is to foresee the influence of different lattice arrangements on material properties, and to predict the change trend of the lattice under different conditions through simulation, thereby determining an optimal reorganization strategy; Placing the quantum well layer in a nitrogen environment, and controlling the nitrogen partial pressure and temperature based on the lattice recombination algorithm to obtain a primary quantum well layer; Performing ion beam implantation on the primary quantum well layer based on fast ion beam technology to optimize the lattice arrangement of the primary quantum well layer to obtain an intermediate quantum well layer; Performing secondary characterization on the intermediate quantum well layer to obtain an optimized quantum well layer; A metal electrode is deposited on the optimized quantum well layer to form an electric contact layer, thereby obtaining the multi-layer VCSEL chip.

2. The method for preparing a multi-layer VCSEL chip according to claim 1, characterized in that: The aluminum oxide material is any one of aluminum oxide or aluminum nitride oxide or a combination of several thereof, and the silicon nitride material is any one of silicon nitride or silicon nitride or a combination of several thereof.

3. The method for preparing a multi-layer VCSEL chip according to claim 1, characterized in that: The semiconductor material is any one of indium phosphide, gallium arsenide and gallium nitride or a combination of several of them.

4. The method for preparing a multi-layer VCSEL chip according to claim 1, characterized in that: The step of performing electron beam lithography on the single crystal silicon substrate to obtain a substrate having a predetermined nano-patterned structure comprises: The surface of the single crystal silicon substrate is subjected to ultrasonic cleaning treatment based on deionized water and ethanol solution to obtain a clean substrate surface; Applying electron beam photoresist to the cleaned substrate surface based on spin coating, wherein the coating of the electron beam photoresist is 300 nanometers; The substrate coated with the photoresist is subjected to a soft drying process, wherein the temperature is set to 80-90° C. and the drying is continued for 25-30 seconds to obtain a dried substrate; Exposing the dried substrate using an electron beam exposure device, wherein the exposure dose is set to 480-500 μC / cm² and the exposure time is set to 5-6 seconds to form a predetermined nano-patterned structure; The exposed substrate is developed with a developer to dissolve the unexposed portion of the photoresist, thereby obtaining a substrate with a predetermined nano-patterned structure on the surface of the substrate.

5. The method for preparing a multi-layer VCSEL chip according to claim 1, characterized in that: The step of introducing an aminosilane gas source into the surface of the substrate so that the substrate and the aminosilane gas source react with each other to obtain a substrate covered with a monomolecular layer comprises: The substrate surface is subjected to substrate surface electron beam irradiation treatment, wherein the irradiation energy is set to 50-60 keV and the irradiation dose is set to 10-15 µC / cm², so that negatively charged active sites are generated on the substrate surface; placing the substrate into a reaction chamber and introducing aminosilane gas, so that the aminosilane gas reacts with the active sites to form a monomolecular layer; Introducing nitrogen into the reaction chamber for gas exchange, wherein the nitrogen flow rate is 50-60 sccm, maintaining the chamber pressure at 50-60 Pa, and continuing to purge for 30-35 minutes; The reaction product between the aminosilane molecule and the substrate surface is detected by spectroscopy to obtain the formation of the monolayer, and the thickness of the monolayer is adjusted based on the formation to obtain a substrate covered with the monolayer.

6. The method for preparing a multi-layer VCSEL chip according to claim 5, characterized in that: The step of using spectroscopy to detect the reaction product between the aminosilane molecules and the substrate surface to obtain the formation of a monolayer, and adjusting the thickness of the monolayer based on the formation to obtain a substrate covered with a monolayer comprises: Performing Fourier transform infrared spectroscopy analysis on the substrate to detect the chemical bonding between the substrate surface and the aminosilane to obtain spectral data, wherein the spectral data includes characteristic peak data of molecular vibration after the substrate surface reaction; The spectrum baseline is corrected based on the polynomial fitting method to obtain the corrected characteristic peak data; Performing peak extraction on the corrected characteristic peak data, decomposing multiple overlapping peaks in the spectral data to obtain characteristic peaks, and obtaining the maximum absorption value of each characteristic peak; Fitting the relationship between the maximum absorption value and the coverage of the monolayer on the substrate surface to obtain a quantitative model, and calculating the thickness change value of the monolayer based on the quantitative model; Determine whether the thickness change value is greater than a preset target value. If it is less than, increase the aminosilane gas flow rate or reaction time to increase the deposition amount of the molecular layer; if it is greater than, reduce the aminosilane gas flow rate or reaction time to reduce the deposition amount of the molecular layer; until the thickness of the monomolecular layer reaches the preset target value, a substrate covered with a monomolecular layer is obtained.

7. The method for preparing a multi-layer VCSEL chip according to claim 1, characterized in that: The step of sequentially depositing an aluminum oxide material and a silicon nitride material on a substrate covered with a monomolecular layer to obtain a photonic crystal layer with high reflectivity comprises: Placing the substrate covered with the monomolecular layer in a vacuum chamber, and performing vacuum deposition treatment on the substrate based on a high-purity aluminum target at a current density of 2-3 A / cm² to form an aluminum oxide film; During the vacuum deposition process, the reflectivity of the aluminum oxide film is continuously tested, and if the reflectivity does not reach a preset reflectivity value, the rate and time of vacuum deposition are adjusted until the reflectivity of the aluminum oxide film reaches a preset reflectivity value, thereby forming an aluminum oxide layer; Depositing silicon nitride material on the surface of the aluminum oxide layer to form a silicon nitride film layer, wherein the deposition conditions are to set the flow ratio of nitrogen gas to silicon source gas to 3:1, the temperature to 340-350° C., and the silicon nitride deposition rate to 10-15 nm per minute; The stress distribution of the silicon nitride film layer is obtained based on Raman spectroscopy, and the stress of the silicon nitride film layer is regulated according to the stress distribution result until the stress distribution of the silicon nitride film layer meets the preset requirements to form a photonic crystal layer with high reflectivity.

8. The method for preparing a multi-layer VCSEL chip according to claim 1, characterized in that: The step of depositing a metal electrode on the optimized quantum well layer to form an electrical contact layer to obtain the multi-layer VCSEL chip comprises: Performing an optical interference test on the surface of the optimized quantum well layer to obtain an interference pattern, and obtaining optical uniformity information of the surface of the quantum well layer based on the distribution of interference fringes in the interference pattern; Selecting a corresponding metal electrode material based on the optical uniformity information, and depositing the metal electrode material on the surface of the optimized quantum well layer to form a metal thin film layer; Depositing a thin passivation layer on the metal film layer based on atomic layer deposition technology to form the electrical contact layer; The metal film layer and the thin passivation layer are patterned based on photolithography technology to obtain the multi-layer VCSEL chip.

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