Gallium oxide epitaxial growth method based on transfer bonding

Abstract

The invention discloses a gallium oxide epitaxial growth method based on transfer bonding, which relates to the technical field of semiconductor material preparation, and comprises the following steps: epitaxially growing a gallium oxide thin film layer on a first substrate, and forming a multi-layer oxide bonding intermediate layer; differential plasma activation treatment is carried out on the surface of the multilayer oxide bonding intermediate layer and the surface of the second substrate; aligning and laminating the surface of the activated multilayer oxide bonding intermediate layer and the surface of a second substrate, and applying pressure to the laminated structure to perform pre-bonding treatment; carrying out segmented heating annealing treatment on the pre-bonded structure, so that the multilayer oxide bonding intermediate layer and the second substrate form bonding; and removing the first substrate, and carrying out surface optimization treatment on the surface of the transferred gallium oxide thin film layer. Through the design of the multilayer oxide bonding intermediate layer, the differential plasma activation treatment and the sectional heating annealing process, the bonding interface strength and stability are improved, and the defect density of the gallium oxide thin film is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor material preparation, in particular to a gallium oxide epitaxial growth method based on transfer bonding. Background Art

[0002] As a new generation of ultra-wide bandgap semiconductor material, gallium oxide (GaO) possesses an ultra-wide bandgap, high breakdown electric field strength, and excellent thermal stability, and has important applications in power electronics and radio frequency devices. With the growing demand for high-performance electronic devices, the preparation technology of high-quality GaO thin films has become critical.

[0003] Existing gallium oxide thin film production primarily relies on direct epitaxial growth, but this is limited by the cost and size of high-quality gallium oxide substrates. Transfer bonding technology, as an effective thin film transfer method, can transfer high-quality thin films from a growth substrate to a target substrate. However, during the transfer bonding process of gallium oxide thin films, improper bonding interface treatment leads to insufficient bonding strength, imprecise temperature and pressure control during the bonding process can easily lead to interface defects, and a lack of effective process monitoring methods results in low bonding success rates. These issues have limited the application of transfer bonding technology in the preparation of gallium oxide thin films. Summary of the Invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a gallium oxide epitaxial growth method based on transfer bonding, which is used to solve the technical problems of weak bonding interface bonding force, high bonding failure rate and unstable transfer film quality in the existing transfer bonding technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a gallium oxide epitaxial growth method based on transfer bonding, comprising:

[0008] Epitaxially growing a gallium oxide thin film layer on a first substrate, and forming a multi-layer oxide bonding intermediate layer on the surface of the gallium oxide thin film layer;

[0009] Cleaning the surface of the second substrate, and performing differential plasma activation treatment on the surface of the multi-layer oxide bonding intermediate layer and the surface of the second substrate;

[0010] Aligning and laminating the surface of the activated multi-layer oxide bonding intermediate layer with the surface of the second substrate, and applying pressure to the laminating structure to perform a pre-bonding treatment;

[0011] Performing a segmented heating annealing process on the pre-bonded structure to bond the multi-layer oxide bonding intermediate layer to the second substrate;

[0012] The first substrate is removed, the gallium oxide thin film layer transferred to the second substrate is retained, and the surface of the transferred gallium oxide thin film layer is subjected to surface optimization treatment.

[0013] As a preferred embodiment of the gallium oxide epitaxial growth method based on transfer bonding of the present invention, forming a multi-layer oxide bonding intermediate layer includes:

[0014] epitaxially growing a gallium oxide thin film layer on a first substrate using molecular beam epitaxy;

[0015] Using chemical vapor deposition to sequentially deposit a first oxide sublayer, a second oxide sublayer, and a third oxide sublayer on the surface of the gallium oxide thin film layer to form a multi-layer oxide bonding intermediate layer;

[0016] The surface of the multi-layer oxide bonding intermediate layer is rinsed with deionized water and dried with nitrogen.

[0017] As a preferred embodiment of the gallium oxide epitaxial growth method based on transfer bonding of the present invention, the differential plasma activation treatment includes:

[0018] performing organic solvent cleaning and deionized water cleaning treatment on the surface of the second substrate;

[0019] generating a plasma activation processing parameter set based on material properties of the multi-layer oxide bonding intermediate layer and the second substrate;

[0020] performing plasma activation treatment on the surface of the multi-layer oxide bonding intermediate layer and the surface of the second substrate according to a plasma activation treatment parameter set;

[0021] The surface energies of the activated multilayer oxide bonding intermediate layer and the second substrate are tested to determine whether they meet a first preset standard.

[0022] As a preferred embodiment of the gallium oxide epitaxial growth method based on transfer bonding of the present invention, aligning and bonding the surface of the activated multi-layer oxide bonding intermediate layer with the surface of the second substrate comprises:

[0023] Loading the first substrate and the second substrate carrying the multi-layer oxide bonding intermediate layer onto the upper and lower platforms of the bonding equipment respectively;

[0024] Perform optical alignment using a bonding device to adjust the relative positions of the upper and lower platforms so that the surface of the activated multi-layer oxide bonding intermediate layer is aligned with the surface of the second substrate;

[0025] In a preset environment, controlling the movement of the carrier to make the surface of the multi-layer oxide bonding intermediate layer adhere to the surface of the second substrate;

[0026] Applying progressive pressure to the bonded structure to a preset pressure value;

[0027] Maintain the preset pressure value for a preset time to complete the pre-bonding process;

[0028] Detecting the interface bonding state after pre-bonding to determine whether the pre-bonding quality meets the second preset standard.

[0029] As a preferred embodiment of the gallium oxide epitaxial growth method based on transfer bonding of the present invention, the stepwise heating annealing of the pre-bonded structure includes:

[0030] Transferring the pre-bonded structure to an annealing device and heating it to a first preset temperature for pre-annealing;

[0031] Controlling the cooling rate, cooling from the third preset temperature to the second preset temperature, and heating to the second preset temperature to perform a medium-temperature bonding strengthening treatment;

[0032] Continue heating to a third preset temperature to perform high-temperature complete bonding treatment;

[0033] Controlling the cooling rate to cool from the third preset temperature to the second preset temperature to perform a medium-temperature stabilization process;

[0034] Continue to cool down to room temperature to complete the segmented heating annealing process;

[0035] A bonding quality test is performed on the structure after the segmented heating annealing process to determine whether it meets the third preset standard.

[0036] As a preferred embodiment of the gallium oxide epitaxial growth method based on transfer bonding of the present invention, the surface optimization treatment of the transferred gallium oxide thin film layer comprises:

[0037] thinning the first substrate by mechanical grinding;

[0038] removing the remaining first substrate by chemical selective etching to obtain a gallium oxide thin film layer transferred to the second substrate;

[0039] Cleaning the surface of the gallium oxide thin film layer;

[0040] The upper surface of the gallium oxide thin film layer is planarized using a surface polishing technique.

[0041] As a preferred embodiment of the gallium oxide epitaxial growth method based on transfer bonding of the present invention, generating a plasma activation processing parameter group includes:

[0042] Obtaining material property data of the multi-layer oxide bonding intermediate layer and the second substrate; the material property data includes chemical composition, surface energy and thermal stability;

[0043] determining first plasma activation processing parameters according to material property data of the multi-layer oxide bonding intermediate layer;

[0044] determining a second plasma activation processing parameter according to the material characteristic data of the second substrate;

[0045] The first plasma activation process parameter and the second plasma activation process parameter are combined to form a plasma activation process parameter set.

[0046] In a second aspect, the present invention provides a gallium oxide epitaxial growth system based on transfer bonding, comprising:

[0047] an epitaxial growth module, configured to epitaxially grow a gallium oxide thin film layer on a first substrate and form a multi-layer oxide bonding intermediate layer on a surface of the gallium oxide thin film layer;

[0048] a surface treatment module, configured to clean the surface of the second substrate and perform differential plasma activation treatment on the surface of the multi-layer oxide bonding intermediate layer and the surface of the second substrate;

[0049] A bonding processing module is used to align and bond the surface of the activated multi-layer oxide bonding intermediate layer with the surface of the second substrate, and apply pressure to the bonded structure to perform pre-bonding processing;

[0050] An annealing treatment module is used to perform a segmented heating annealing treatment on the structure after the pre-bonding treatment, so that the multi-layer oxide bonding intermediate layer forms a bond with the second substrate;

[0051] The transfer processing module is used to remove the first substrate, retain the gallium oxide thin film layer transferred to the second substrate, and perform surface optimization processing on the surface of the transferred gallium oxide thin film layer.

[0052] In a third aspect, the present invention provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein when the computer program is executed by the processor, any step of the gallium oxide epitaxial growth method based on transfer bonding as described in the first aspect of the present invention is implemented.

[0053] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, any step of the gallium oxide epitaxial growth method based on transfer bonding as described in the first aspect of the present invention is implemented.

[0054] The beneficial effects of the present invention are as follows: through the design of a multi-layer oxide bonding intermediate layer and differentiated plasma activation treatment, high-quality interface bonding is achieved, and the interface defect density and bonding failure rate are reduced. Optical alignment technology is used to achieve precise positioning, combined with progressive pressure control to ensure the bonding accuracy and uniformity of pressure distribution, avoid bonding defects caused by alignment deviation and uneven pressure, and reduce mechanical damage. A segmented heating annealing treatment is adopted, and multi-stage temperature control is used to effectively alleviate the thermal stress generated by the difference in thermal expansion coefficients between different materials, thereby improving the thermal stability of the bonding structure. The process controllability and product consistency are improved through a multi-node quality detection system, which significantly improves the bonding success rate. The first substrate is removed by combining mechanical grinding and chemical selective etching to avoid damage to the gallium oxide film and obtain a transfer film with excellent surface quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0056] Figure 1 Flowchart of the gallium oxide epitaxial growth method based on transfer bonding.

[0057] Figure 2 A flow chart was generated for a set of plasma activation processing parameters for a transfer bonding-based gallium oxide epitaxial growth method.

[0058] Figure 3 The figure shows the pre-bonding process flow chart of the gallium oxide epitaxial growth method based on transfer bonding.

[0059] Figure 4 This is a module connection diagram of the gallium oxide epitaxial growth system based on transfer bonding. DETAILED DESCRIPTION

[0060] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0061] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0062] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0063] Reference Figures 1 to 4 , is an embodiment of the present invention, which provides a gallium oxide epitaxial growth method based on transfer bonding, the flow chart is as follows Figure 1 As shown, the method includes the following steps:

[0064] S1: epitaxially growing a gallium oxide thin film layer on a first substrate, and forming a multi-layer oxide bonding intermediate layer on the surface of the gallium oxide thin film layer.

[0065] Specifically, step S1 includes:

[0066] S1.1: epitaxially grow a gallium oxide thin film layer on the first substrate using molecular beam epitaxy.

[0067] Optionally, the first substrate includes but is not limited to a sapphire substrate, a gallium oxide substrate or a silicon carbide substrate.

[0068] In one specific embodiment, the molecular beam epitaxy equipment is pretreated, the vacuum chamber is evacuated to an ultra-high vacuum environment, and the interior of the molecular beam epitaxy equipment is baked. The first substrate is pretreated and cleaned, including degreasing with an organic solvent and rinsing with deionized water. After cleaning, the first substrate is loaded onto a substrate holder. Epitaxial growth parameters are set, including substrate temperature, oxygen partial pressure, and gallium beam intensity. During the epitaxial growth process, the film growth process is monitored using a reflected high-energy electron diffraction device. When the gallium oxide film layer reaches a preset thickness, growth is stopped, and the substrate temperature is slowly lowered to room temperature in an oxygen atmosphere to obtain a gallium oxide film layer with good crystal quality.

[0069] S1.2: Using chemical vapor deposition, a first oxide sublayer, a second oxide sublayer, and a third oxide sublayer are sequentially deposited on the surface of the gallium oxide thin film layer to form a multi-layer oxide bonding intermediate layer.

[0070] It should be noted that the design of the multi-layer oxide bonding interlayer is mainly to solve the problems of thermal expansion coefficient mismatch and interface stress concentration between gallium oxide and the heterogeneous substrate. Gallium oxide has significant anisotropic thermal expansion characteristics. A single oxide interlayer is difficult to effectively relieve thermal stress, which can easily lead to cracking or delamination of the bonding interface. By constructing a multi-layer structure, each oxide sublayer can perform different functions: the bottom layer provides chemical stability and adhesion, the middle layer acts as a stress buffer, and the top layer optimizes the bonding interface characteristics. The chemical vapor deposition process is used because it can achieve continuous deposition of multiple oxide materials under suitable temperature conditions, with good thickness control accuracy and large-area uniformity. At the same time, the chemical bonding interface formed by chemical vapor deposition has a higher bonding strength than the physical deposition method, which is more suitable for subsequent high-temperature bonding annealing treatment.

[0071] Based on the above functional requirements, each oxide sublayer uses oxide materials such as silicon dioxide and aluminum oxide that have good interface compatibility and thermal matching with gallium oxide, and the material combination design is carried out according to the layered function to achieve the comprehensive effects of chemical stability, stress buffering and interface optimization.

[0072] During the process implementation, chemical vapor deposition is used to deposit the first oxide sublayer on the surface of the gallium oxide thin film layer, and the deposition thickness and deposition temperature are controlled; the second oxide sublayer is deposited on the surface of the first oxide sublayer, and the precursor gas flow ratio is adjusted to optimize the film quality; the third oxide sublayer is deposited on the surface of the second oxide sublayer, and the interface roughness between the oxide sublayers is controlled to complete the construction of the multi-layer oxide bonding intermediate layer.

[0073] S1.3: Rinse the surface of the multi-layer oxide bonding intermediate layer with deionized water and dry it with nitrogen.

[0074] In this step, the deionized water rinse and nitrogen drying treatment are to remove surface particle contaminants and process residues that may be generated during the chemical vapor deposition process, ensure that the surface of the multi-layer oxide bonding intermediate layer is in a clean state, and provide good surface conditions for subsequent plasma activation treatment.

[0075] S2: Cleaning the surface of the second substrate and performing differential plasma activation treatment on the surface of the multi-layer oxide bonding intermediate layer and the surface of the second substrate.

[0076] Specifically, step S2 includes:

[0077] S2.1: Clean the surface of the second substrate with an organic solvent and deionized water.

[0078] Optionally, the second substrate includes but is not limited to a silicon substrate, a gallium nitride substrate or a diamond substrate.

[0079] In this step, organic solvent cleaning and deionized water cleaning are used to remove different types of contaminants from the second substrate surface. The organic solvent primarily removes grease and organic residues, while the deionized water primarily removes ionic contaminants and organic solvent residues. This combined cleaning ensures the cleanliness of the bonding interface, thereby improving the interfacial bonding strength and bond quality of the subsequent bonding process.

[0080] S2.2: Generate a plasma activation processing parameter set according to the material properties of the multi-layer oxide bonding intermediate layer and the second substrate.

[0081] Specifically, the plasma activation process parameter group generation flow chart is as follows: Figure 2 Shown, including:

[0082] S2.2.1: Obtain material property data for the multilayer oxide bonding intermediate layer and the second substrate.

[0083] The material property data includes, but is not limited to, chemical composition, layer thickness, surface roughness, thermal stability, thermal expansion coefficient, and surface chemical bonding characteristics.

[0084] S2.2.2: Determine first plasma activation processing parameters based on material property data of the multi-layer oxide bonding intermediate layer.

[0085] In one embodiment, the plasma gas type is determined based on the chemical composition of the multi-layer oxide bonding intermediate layer, the plasma power is selected based on the layer thickness and material hardness, and the processing temperature range and processing time range are set based on thermal stability, thereby determining the first plasma activation processing parameters suitable for the multi-layer oxide bonding intermediate layer.

[0086] S2.2.3: Determine second plasma activation processing parameters based on the material characteristic data of the second substrate.

[0087] In another embodiment, the plasma power and processing time range are selected according to the surface roughness of the second substrate, the processing temperature range is set according to the thermal expansion coefficient, and the plasma gas combination and processing time range are determined according to the surface chemical bonding characteristics, thereby determining the second plasma activation processing parameters suitable for the second substrate.

[0088] S2.2.4: Combine the first plasma activation processing parameter and the second plasma activation processing parameter to form a plasma activation processing parameter set.

[0089] S2.3: Performing plasma activation treatment on the surface of the multi-layer oxide bonding intermediate layer and the surface of the second substrate according to the plasma activation treatment parameter set.

[0090] During the implementation process, the plasma equipment is configured according to the plasma activation process parameter set. After the equipment is configured, parameter stability is verified. Activation treatments are then performed on the surface of the multilayer oxide bonding intermediate layer and the second substrate, respectively. Equipment parameters are reconfigured between activation treatments to ensure that each surface receives an activation effect appropriate for its material properties. Parameter stability verification involves testing the stability of process parameters such as plasma equipment power, gas flow rate, and chamber pressure.

[0091] S2.4: Test the surface energy of the activated multilayer oxide bonding intermediate layer and the second substrate to determine whether they meet the first preset standard.

[0092] It should be noted that the first preset standard is that the surface energy of the multi-layer oxide bonding intermediate layer and the second substrate both meet the bonding requirements, and there are no contaminants and defects on the surface that affect bonding. The bonding requirements are determined based on the specific material combination and bonding application requirements.

[0093] Through the above steps, differentiated plasma activation treatment and all-round quality control are achieved, solving the process difficulties in multi-material bonding. Customized plasma parameters are automatically generated based on material property data, avoiding the limitations of traditional one-size-fits-all treatment methods, so that different materials can obtain suitable surface activation states. A complete closed-loop control system from cleaning to activation to testing has been established. Through the dual standards of surface energy compliance and surface quality testing, it is ensured that the bonding interface meets the process requirements, improving process repeatability and batch consistency. The intelligent parameter generation mechanism reduces the trial and error time in process development, and with real-time quality testing and feedback adjustment, it shortens the production cycle and reduces the scrap rate.

[0094] S3: Align and bond the surface of the activated multi-layer oxide bonding intermediate layer with the surface of the second substrate, and apply pressure to the bonded structure to perform a pre-bonding treatment.

[0095] Specifically, the pre-bonding process flow chart is as follows: Figure 3 Shown, including:

[0096] S3.1: Loading the first substrate and the second substrate carrying the multi-layer oxide bonding intermediate layer onto the upper and lower platforms of the bonding equipment respectively.

[0097] During loading, it should be ensured that the surface of the multi-layer oxide bonding intermediate layer of the first substrate faces the second substrate, and the two substrates remain parallel, with an appropriate gap reserved between the carriers for subsequent precision alignment operations.

[0098] S3.2: Perform optical alignment using a bonding device to adjust the relative positions of the upper and lower platforms so that the surface of the activated multi-layer oxide bonding intermediate layer is aligned with the surface of the second substrate.

[0099] Preferably, a real-time image of the surface of the multilayer oxide bonding intermediate layer and the surface of the second substrate is acquired through an optical microscope of the bonding equipment, and characteristic marking points on the surface of the multilayer oxide bonding intermediate layer and the surface of the second substrate are identified. A coordinate mapping relationship between the characteristic marking points on the surface of the multilayer oxide bonding intermediate layer and the characteristic marking points on the surface of the second substrate is established, and a positional deviation between the surface of the multilayer oxide bonding intermediate layer and the surface of the second substrate is calculated. Based on the positional deviation, a stage adjustment instruction is generated to control the upper stage to perform X-axis translation adjustment, Y-axis translation adjustment, and θ-angle rotation adjustment.

[0100] After executing the stage adjustment command, real-time images of the surface of the multilayer oxide bonding intermediate layer and the surface of the second substrate are reacquired, and the adjusted position deviation is calculated. A determination is made as to whether the adjusted position deviation is within the preset alignment accuracy range. If it is, the adjustment process is repeated. If it is, the stage position is fixed. The relative positions of the upper and lower stages are fixed to achieve precise alignment of the surface of the multilayer oxide bonding intermediate layer and the surface of the second substrate. The preset alignment accuracy range is determined based on the bonding area size and the subsequent device processing accuracy requirements.

[0101] Optimally, a closed-loop control technology integrating optical microscopy imaging, feature point recognition, and three-axis precision adjustment achieves high-precision automated alignment of the multilayer oxide bonding intermediate layer and the secondary substrate. This technical solution improves alignment accuracy and consistency during the transfer bonding process, laying a critical foundation for the subsequent formation of a high-quality bonding interface and effectively addressing the issue of bonding failure caused by alignment deviation during the transfer of gallium oxide thin films.

[0102] S3.3: In a preset environment, control the movement of the carrier to make the surface of the multi-layer oxide bonding intermediate layer adhere to the surface of the second substrate.

[0103] Preferably, the preset environment is a vacuum environment or an inert gas environment.

[0104] Furthermore, the upper loading platform is controlled to move toward the unloading platform at a set speed. The distance between the upper loading platform and the unloading platform is monitored in real time. When the distance reaches the preset bonding distance, the carrier movement speed is automatically reduced to the precision contact speed. When initial contact is detected between the surface of the multi-layer oxide bonding intermediate layer and the surface of the second substrate, the carrier movement is stopped and the contact position is recorded. The contact area is controlled to gradually expand from the initial contact point to the surrounding area. The local pressure distribution during the contact expansion process is monitored in real time through the local pressure sensor array. The carrier posture and pressure are adjusted according to the monitoring results to ensure that the two surfaces are evenly bonded and to avoid the generation of bubbles or stress concentration.

[0105] After surface bonding is complete, the carrier position is kept stable while the contact quality of the bonding interface is tested. Once the bonding state is confirmed to meet the bonding quality standards, the carrier position is locked, completing the precision bonding of the multi-layer oxide bonding intermediate layer surface and the second substrate surface. The bonding quality standards are determined based on the bonding material characteristics, bonding area dimensions, and subsequent annealing process requirements.

[0106] Preferably, the contact uniformity and bonding strength of the bonding interface can be improved through segmented precision lamination control. This method can reduce interface defects caused by improper lamination and provide a good initial bonding state for subsequent high-temperature annealing treatment.

[0107] S3.4: Apply progressive pressure to the bonded structure up to a predetermined pressure value.

[0108] Specifically, a phased approach is used to gradually increase the pressure to avoid sudden impact damage to the film. The preset pressure value is determined based on the mechanical properties of the bonding material, the thickness of the film layer, and the required interfacial bond strength. Mechanical properties determine the material's upper pressure limit, film thickness affects pressure transmission efficiency, and interfacial bond strength determines the minimum pressure threshold.

[0109] It should be noted that the laminated structure refers to the entire structure formed by the first substrate, the gallium oxide thin film layer, the multi-layer oxide bonding intermediate layer, and the second substrate. By applying progressive pressure to this overall structure, close contact and initial bonding between the multi-layer oxide bonding intermediate layer and the surface of the second substrate can be promoted.

[0110] S3.5: Maintain the preset pressure value for a preset time to complete the pre-bonding process.

[0111] The preset time is determined by the interfacial bonding properties of the bonding material and the pressure. The interfacial bonding properties determine the base time for the intermolecular forces to establish, while the pressure affects the degree of acceleration of the bonding process.

[0112] Furthermore, the constant pressure is maintained for a predetermined time to allow the interface to fully bond and form initial bond strength. By properly controlling the holding time, an optimal balance is achieved between ensuring full interface bonding and avoiding excessive stress relaxation.

[0113] S3.6: Detect the interface bonding state after pre-bonding and determine whether the pre-bonding quality meets the second preset standard.

[0114] It should be noted that the quality of the pre-bonding directly determines whether the subsequent annealing can successfully form a permanent bond. Inadequate pre-bonding will fail during the heat treatment process, leading to the failure of the entire transfer bonding process. For example, the second preset standard can be: the interface bonding strength meets the heat treatment requirements, the interface coverage reaches the set requirements (such as 95%), defects such as bubbles are controlled within the allowable range, and there is no large-scale detachment or delamination at the interface.

[0115] Specifically, if the pre-bonding quality meets the second preset standard, the qualified pre-bonding structure will be transferred to the next process and enter the segmented heating annealing treatment; if the pre-bonding quality does not meet the second preset standard, the corresponding repair strategy will be selected according to the defect analysis results: adjust the process parameters to re-pre-bond, re-execute part of the process or terminate the current process.

[0116] S4: performing a segmented heating annealing process on the structure after the pre-bonding process, so that the multi-layer oxide bonding intermediate layer is bonded to the second substrate.

[0117] Specifically, step S4 includes:

[0118] S4.1: Transferring the pre-bonded structure to an annealing device, heating it to a first preset temperature for pre-annealing to activate the bonding interface activity.

[0119] In one embodiment, pre-annealing involves heat treating the pre-bonded structure at a first preset temperature. This process primarily removes residual organic contaminants and moisture from the bonding interface, increases the reactivity of interfacial atoms, and creates favorable interfacial conditions for subsequent bonding. During the pre-annealing process, the hydroxyl groups on the surface of the multilayer oxide bonding intermediate layer begin to activate, promoting interfacial chemical reactions. The pre-annealing treatment is held at this temperature for 1-2 hours to ensure complete activation of the gallium oxide surface.

[0120] S4.2: Control the cooling rate, cool down from the third preset temperature to the second preset temperature, and then heat up to the second preset temperature to perform a medium-temperature bonding strengthening treatment to promote interface chemical bonding.

[0121] Specifically, the medium-temperature bonding strengthening treatment is a key process step carried out at the second preset temperature. At this temperature, the multi-layer oxide bonding intermediate layer undergoes a preliminary chemical reaction with the surface of the second substrate, the interfacial hydroxyl groups are further dehydrated to form chemical bonds, the bonding area gradually expands, and the bonding strength is initially improved, laying the foundation for high-temperature complete bonding.

[0122] S4.3: Continue to raise the temperature to a third preset temperature and perform high-temperature complete bonding treatment to achieve complete chemical bonding at the interface.

[0123] Furthermore, a high-temperature complete bonding treatment achieves complete chemical bonding at the interface at a third preset temperature. At this stage, atomic diffusion is more complete, and the chemical bond reaches maximum strength. The multi-layer oxide bonding intermediate layer forms a continuous interface structure with the second substrate, achieving a strong mechanical bond and good interface stability. The high-temperature complete bonding treatment is held at this temperature for 1-2 hours, ensuring complete bonding while preventing film performance degradation.

[0124] S4.4: Cooling the temperature from the third preset temperature to the second preset temperature at a controlled cooling rate to perform a medium-temperature stabilization treatment.

[0125] It should be noted that after high-temperature full bonding treatment, if the temperature is directly cooled to room temperature, the bonding interface will generate large thermal stress due to the difference in thermal expansion coefficient. This thermal stress may cause microcracks in the interface or reduce the bond strength. By introducing a medium-temperature stabilization treatment, a buffer stage can be provided for the bonding interface during the cooling process, allowing the interface structure to relax stress at a moderate temperature, reducing the thermal stress caused by the difference in thermal expansion coefficient and improving the interface bonding quality.

[0126] Furthermore, the medium-temperature stabilization treatment controls the cooling process and maintains the second preset temperature for a certain period of time, so that the bonding interface can adjust the stress under appropriate temperature conditions, improve the interface bonding quality and uniformity, and avoid the risk of interface cracking that may be caused by direct cooling.

[0127] S4.5: Continue cooling to room temperature to complete the segmented heating annealing process.

[0128] It should be noted that the first, second, and third preset temperatures are set based on the gallium oxide material properties and bonding mechanism. Preferably, the first preset temperature is 200-300°C, the second preset temperature is 300-450°C, and the third preset temperature is 450-550°C. This temperature setting ensures effective bonding while avoiding thermal damage to the gallium oxide film caused by excessively high temperatures.

[0129] Preferably, the segmented temperature control strategy achieves precise control of bonding quality through a process route of low-temperature pretreatment, medium-temperature chemical bonding, high-temperature complete bonding, and medium-temperature stabilization, effectively improving the success rate of gallium oxide film transfer and interface bonding strength.

[0130] S4.6: Perform a bonding quality test on the structure after the segmented heating annealing process to determine whether it meets the third preset standard.

[0131] Bond quality testing includes testing the shear strength of the bond interface and detecting interface defects. Furthermore, a third pre-set criterion includes ensuring the shear strength of the bond interface meets substrate removal requirements and that the interface is free of cracks and delamination defects that would affect substrate removal. The specific numerical requirements are determined based on the mechanical requirements of subsequent mechanical grinding and chemical etching processes.

[0132] S5: removing the first substrate, retaining the gallium oxide thin film layer transferred to the second substrate, and performing surface optimization treatment on the surface of the transferred gallium oxide thin film layer.

[0133] Specifically, step S5 includes:

[0134] S5.1: Thinning the first substrate by mechanical grinding.

[0135] S5.2: Remove the remaining first substrate by chemical selective etching to obtain a gallium oxide thin film layer transferred to the second substrate.

[0136] Preferably, through a combined treatment of mechanical grinding and chemical selective etching, the first substrate can be effectively removed while ensuring the integrity of the gallium oxide film, thereby obtaining a transferred film with good surface quality.

[0137] S5.3: Clean the surface of the gallium oxide thin film layer to remove residues and surface contamination generated during the separation process.

[0138] In this step, the cleaning process includes acid cleaning, alkaline cleaning, deionized water cleaning and drying, which effectively removes pollutants while avoiding excessive corrosion or surface damage to the gallium oxide thin film layer.

[0139] S5.4: Planarize the upper surface of the gallium oxide thin film layer using a surface polishing technique.

[0140] Specifically, the planarization process involves securing the transferred gallium oxide film layer to the polishing equipment's worktable and adjusting polishing parameters. A rough polishing process is then used to initially planarize the upper surface of the gallium oxide film layer to remove any macroscopic surface irregularities. The fine polishing pad and slurry are then replaced, and the upper surface of the gallium oxide film layer is finely polished. Finally, chemical mechanical polishing is used to planarize the upper surface of the gallium oxide film layer to achieve an ultra-smooth surface. The polished upper surface of the gallium oxide film layer is then cleaned and dried to remove polishing residue.

[0141] S5.5: Perform surface protection treatment on the gallium oxide thin film layer according to the application scenario requirements.

[0142] Preferably, the first substrate is removed by combining mechanical grinding and chemical selective etching, and surface polishing is used to improve the success rate of film transfer and the surface flatness and crystal integrity of the transferred gallium oxide film.

[0143] This embodiment also provides a gallium oxide epitaxial growth system based on transfer bonding, the module connection diagram is as follows Figure 4 As shown, the system includes:

[0144] an epitaxial growth module, configured to epitaxially grow a gallium oxide thin film layer on a first substrate and form a multi-layer oxide bonding intermediate layer on a surface of the gallium oxide thin film layer;

[0145] a surface treatment module, configured to clean the surface of the second substrate and perform differential plasma activation treatment on the surface of the multi-layer oxide bonding intermediate layer and the surface of the second substrate;

[0146] A bonding processing module is used to align and bond the surface of the activated multi-layer oxide bonding intermediate layer with the surface of the second substrate, and apply pressure to the bonded structure to perform pre-bonding processing;

[0147] An annealing treatment module is used to perform a segmented heating annealing treatment on the structure after the pre-bonding treatment, so that the multi-layer oxide bonding intermediate layer forms a bond with the second substrate;

[0148] The transfer processing module is used to remove the first substrate, retain the gallium oxide thin film layer transferred to the second substrate, and perform surface optimization processing on the surface of the transferred gallium oxide thin film layer.

[0149] This embodiment also provides a computer device, which is applicable to the gallium oxide epitaxial growth method based on transfer bonding, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the gallium oxide epitaxial growth method based on transfer bonding as proposed in the above embodiment.

[0150] The computer device may be a terminal, comprising a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device comprises a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner may be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a button, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse.

[0151] This embodiment also provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the gallium oxide epitaxial growth method based on transfer bonding as proposed in the above embodiment; the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0152] In summary, the present invention achieves high-quality interface bonding and reduces interface defect density and bonding failure rate through multi-layer oxide bonding intermediate layer design and differentiated plasma activation treatment. Optical alignment technology is used to achieve precise positioning, combined with progressive pressure control to ensure bonding accuracy and uniformity of pressure distribution, avoid bonding defects caused by alignment deviation and uneven pressure, and reduce mechanical damage. A segmented heating annealing treatment is adopted, and multi-stage temperature control is used to effectively alleviate the thermal stress generated by the difference in thermal expansion coefficients between different materials, thereby improving the thermal stability of the bonding structure. The process controllability and product consistency are improved through a multi-node quality detection system, which significantly improves the bonding success rate. The first substrate is removed by combining mechanical grinding and chemical selective etching to avoid damage to the gallium oxide film and obtain a transfer film with excellent surface quality.

[0153] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A gallium oxide epitaxial growth method based on transfer bonding, characterized in that: include: Epitaxially growing a gallium oxide thin film layer on a first substrate, and forming a multi-layer oxide bonding intermediate layer on the surface of the gallium oxide thin film layer; Cleaning the surface of the second substrate, and performing differential plasma activation treatment on the surface of the multi-layer oxide bonding intermediate layer and the surface of the second substrate; Aligning and laminating the surface of the activated multi-layer oxide bonding intermediate layer with the surface of the second substrate, and applying pressure to the laminating structure to perform a pre-bonding treatment; Performing a segmented heating annealing process on the pre-bonded structure to bond the multi-layer oxide bonding intermediate layer to the second substrate; The first substrate is removed, and the gallium oxide thin film layer transferred to the second substrate is retained, and a surface optimization treatment is performed on the surface of the transferred gallium oxide thin film layer.

2. The gallium oxide epitaxial growth method based on transfer bonding according to claim 1, wherein: The forming of the multi-layer oxide bonding intermediate layer comprises: epitaxially growing a gallium oxide thin film layer on a first substrate using molecular beam epitaxy; Using chemical vapor deposition to sequentially deposit a first oxide sublayer, a second oxide sublayer, and a third oxide sublayer on the surface of the gallium oxide thin film layer to form a multi-layer oxide bonding intermediate layer; The surface of the multi-layer oxide bonding intermediate layer is rinsed with deionized water and dried with nitrogen.

3. The gallium oxide epitaxial growth method based on transfer bonding according to claim 1, wherein: The differential plasma activation treatment comprises: performing organic solvent cleaning and deionized water cleaning treatment on the surface of the second substrate; generating a plasma activation processing parameter set based on material properties of the multi-layer oxide bonding intermediate layer and the second substrate; performing plasma activation treatment on the surface of the multi-layer oxide bonding intermediate layer and the surface of the second substrate according to a plasma activation treatment parameter set; The surface energies of the activated multilayer oxide bonding intermediate layer and the second substrate are tested to determine whether they meet a first preset standard.

4. The gallium oxide epitaxial growth method based on transfer bonding according to claim 1, wherein: The step of aligning and bonding the surface of the activated multilayer oxide bonding intermediate layer to the surface of the second substrate comprises: Loading the first substrate and the second substrate carrying the multi-layer oxide bonding intermediate layer onto the upper and lower platforms of the bonding equipment respectively; Perform optical alignment using a bonding device to adjust the relative positions of the upper and lower platforms so that the surface of the activated multi-layer oxide bonding intermediate layer is aligned with the surface of the second substrate; In a preset environment, controlling the movement of the carrier to make the surface of the multi-layer oxide bonding intermediate layer adhere to the surface of the second substrate; Applying progressive pressure to the bonded structure to a preset pressure value; Maintaining the preset pressure value for a preset time to complete the pre-bonding process; Detecting the interface bonding state after pre-bonding to determine whether the pre-bonding quality meets the second preset standard.

5. The gallium oxide epitaxial growth method based on transfer bonding according to claim 1, wherein: The stepwise heating and annealing of the pre-bonded structure includes: Transferring the pre-bonded structure to an annealing device and heating it to a first preset temperature for pre-annealing; Controlling the cooling rate, cooling from the third preset temperature to the second preset temperature, and heating to the second preset temperature to perform a medium-temperature bonding strengthening treatment; Continue heating to a third preset temperature to perform high-temperature complete bonding treatment; Controlling the cooling rate to cool from the third preset temperature to the second preset temperature to perform a medium-temperature stabilization process; Continue to cool down to room temperature to complete the segmented heating annealing process; A bonding quality test is performed on the structure after the segmented heating annealing process to determine whether it meets the third preset standard.

6. The gallium oxide epitaxial growth method based on transfer bonding according to claim 1, wherein: The surface optimization treatment of the transferred gallium oxide thin film layer comprises: thinning the first substrate by mechanical grinding; removing the remaining first substrate by chemical selective etching to obtain a gallium oxide thin film layer transferred to the second substrate; Cleaning the surface of the gallium oxide thin film layer; The upper surface of the gallium oxide thin film layer is planarized using a surface polishing technique.

7. The gallium oxide epitaxial growth method based on transfer bonding according to claim 3, wherein: The generating of the plasma activation processing parameter group comprises: Obtaining material property data of the multi-layer oxide bonding intermediate layer and the second substrate; the material property data including chemical composition, surface energy and thermal stability; determining first plasma activation processing parameters according to material property data of the multi-layer oxide bonding intermediate layer; determining a second plasma activation processing parameter according to the material characteristic data of the second substrate; The first plasma activation process parameter and the second plasma activation process parameter are combined to form a plasma activation process parameter set.

8. A gallium oxide epitaxial growth system based on transfer bonding, based on the gallium oxide epitaxial growth method based on transfer bonding according to any one of claims 1 to 7, characterized in that: include: an epitaxial growth module, configured to epitaxially grow a gallium oxide thin film layer on a first substrate and form a multi-layer oxide bonding intermediate layer on a surface of the gallium oxide thin film layer; a surface treatment module, configured to clean the surface of the second substrate and perform differential plasma activation treatment on the surface of the multi-layer oxide bonding intermediate layer and the surface of the second substrate; A bonding processing module is used to align and bond the surface of the activated multi-layer oxide bonding intermediate layer with the surface of the second substrate, and apply pressure to the bonded structure to perform pre-bonding processing; An annealing treatment module is used to perform a segmented heating annealing treatment on the structure after the pre-bonding treatment, so that the multi-layer oxide bonding intermediate layer forms a bond with the second substrate; The transfer processing module is used to remove the first substrate, retain the gallium oxide thin film layer transferred to the second substrate, and perform surface optimization processing on the surface of the transferred gallium oxide thin film layer.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the gallium oxide epitaxial growth method based on transfer bonding according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the gallium oxide epitaxial growth method based on transfer bonding according to any one of claims 1 to 7 are implemented.

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