A large-sized epitaxial layer and its peeling method and peeling device

Abstract

The present invention relates to a large-sized epitaxial layer, a peeling method thereof, and a peeling device. The peeling method is based on a growth substrate bonded to a target substrate. The growth substrate includes a heavily doped layer and a target layer. An etching is performed around the edge of the growth substrate to the heavily doped layer to form a first groove. A conductive ring layer is formed in the first groove to contact a working electrode. An etching is performed at a certain distance from the first groove to the heavily doped layer to form a second groove. The second groove is used to inject an appropriate amount of electrolyte solution, and a large-sized epitaxial layer hetero-integrated on the target substrate is obtained through electrochemical etching. Correspondingly, the peeling device is provided with a conductive gasket, a solution chamber, and a sealing ring located between the conductive gasket and the solution chamber. The peeling method and the peeling device can reduce the electron leakage caused by the participation of the electrode in electrolysis, shorten the current transmission path, avoid the problems of uneven current expansion of the traditional single-point electrode and low power utilization rate, and improve the efficiency and uniformity of wet peeling.

Description

Technical Field

[0001] The present invention relates to the fields of material peeling and heterogeneous integration, and particularly to a large-size epitaxial layer, a peeling method thereof, and a peeling device. Background Art

[0002] The application of group III-V nitrides and their alloy materials is inseparable from homoepitaxial and heteroepitaxial growth technologies. The preparation cost of homoepitaxial growth is too high and the experimental period is long. The cost of heteroepitaxial growth is relatively low and the experimental period is relatively short. However, problems such as lattice mismatch and thermal mismatch brought by heteroepitaxial growth substrates will introduce a large number of defects and internal stresses, severely restricting the development of optoelectronic devices and power devices of group III-V nitrides and their alloys. Therefore, the peeling and heterogeneous integration of heteroepitaxial growth substrates have become the key to the application development of group III-V nitrides and their alloys.

[0003] Group III-V nitrides have high chemical stability and cannot be peeled by traditional chemical etching methods. Currently, the commonly used method of peeling group III-V nitrides and their alloys with high-energy lasers is difficult to avoid the influence of high-energy lasers on group III-V nitride thin films and their device structures, and it also limits the design of the target layer, has high process costs, high laser control difficulty, and high preparation costs, restricting the development of group III-V nitride thin films and their devices. The method of wet peeling by providing power through an external circuit utilizes the conductivity difference between different epitaxial layers and can achieve the peeling of nitride epitaxial films. However, for the complete and efficient peeling of large-size nitride epitaxial film wafers, especially the peeling of large-size nitride epitaxial film components with metal structures on the surface, and the stable heterogeneous integration of the peeled films, there are still insurmountable difficulties. Summary of the Invention

[0004] The present invention provides a large-size epitaxial layer, a peeling method thereof, and a peeling device. The peeling method utilizes the conductivity difference between different epitaxial layers. By designing a multi-path annular electrode and isolating electrolyte around the edge of the substrate, while reducing the electron leakage caused by the participation of the electrode in electrolysis, the path of current transmission between the electrode and the corrosion peeling area is shortened, solving the problems of uneven current expansion of a single-point electrode and low electric energy utilization rate in the conventional wet etching method, improving the efficiency and uniformity of wet peeling, achieving the rapid, efficient, and complete peeling of large-size wafer-level epitaxial films, and obtaining a stable heterogeneous integrated epitaxial wafer. This peeling method is also applicable to the peeling of components in epitaxial films, solving the problems of lack of support in conventional heterogeneous integrated epitaxial wafers, high transfer-bonding difficulty, and difficulty in directly preparing subsequent integrated circuits and flexible devices.

[0005] In addition, the peeling method of the present invention adopts an efficient wet etching method, which releases the inherent internal stress generated during the growth and preparation of large-size nitride epitaxial films and components, improves the overall performance of the device, and expands potential application scenarios.

[0006] The present invention also provides a peeling device applicable to this peeling method. By setting a conductive gasket in electrical contact with the working electrode, a liquid-containing cavity at the bottom of the cell body, and a sealing ring between the conductive gasket and the liquid-containing cavity, the design of a multi-path annular electrode and isolated electrolyte is realized, reducing electron leakage caused by the electrode participating in electrolysis. At the same time, the path of current transmission between the electrode and the corrosion peeling area is shortened, improving the uniformity of current expansion and the utilization rate of electric energy, and enhancing the efficiency and uniformity of wet peeling.

[0007] The present invention provides at least the following technical solutions:

[0008] A peeling method for a large-size epitaxial layer includes the following steps:

[0009] Bond a target substrate to a growth substrate including a heavily doped layer and a target layer;

[0010] Form a first mask layer with a first predetermined pattern on the target substrate, and etch the target layer to a certain depth into the heavily doped layer with the first mask layer as a mask, forming a first groove provided around the edge of the growth substrate;

[0011] Form a second mask layer with a second predetermined pattern on the substrate, and etch the target layer to a certain depth into the heavily doped layer with the second mask layer as a mask, forming a second groove. The distance between the adjacent edges of the first groove and the second groove is not less than 1 mm;

[0012] Form a conductive layer in contact with the working electrode in the first groove;

[0013] Inject an appropriate amount of electrolyte solution into the second groove;

[0014] Adopt electrochemical etching of the heavily doped layer to release the target layer, and obtain a large-size epitaxial layer hetero-integrated on the target substrate.

[0015] The second groove is located in the central area of the growth substrate.

[0016] The doping concentration of the heavily doped layer is at least one order of magnitude higher than that of the target layer; the thickness of the heavily doped layer is not less than 100 nm; the liquid level of the electrolyte solution is not higher than the heavily doped layer.

[0017] When the growth substrate is selected as 2 inches, the corrosion voltage for its electrochemical etching is 10 V to 30 V, and the corrosion time is 20 min to 50 min.

[0018] A large-sized epitaxial layer, which is obtained by the above-mentioned peeling method.

[0019] A peeling device for a large-sized epitaxial layer, comprising a base, a substrate placement groove provided on the base; an electrochemically corrosive cell body detachably fixed on the base, the cell body having a side wall and a bottom surface; a counter electrode, a working electrode, a conductive washer and a sealing ring;

[0020] A water injection pipe and a drainage pipe are fixed on the side wall of the cell body, a solution chamber is arranged on the bottom surface, the water injection pipe and the drainage pipe are communicated with the solution chamber, and the counter electrode is connected to the solution chamber;

[0021] When the peeling device works, a growth substrate is placed in the substrate placement groove. A conductive ring layer and a corrosion groove are provided on the growth substrate. The conductive washer is placed on the conductive ring layer and is electrically connected to the working electrode. The sealing ring is placed between the conductive ring layer and the corrosion groove. The lower end of the side wall is detachably fixed on the base, the bottom surface is in contact with the sealing ring, and the electrolyte is injected into the solution chamber along the water injection pipe and flows to the corrosion groove through the solution chamber.

[0022] The solution chamber is an annular pipe, and a plurality of through holes are opened at the bottom of the pipe.

[0023] The solution chamber is a groove structure, and a plurality of openings are opened at the bottom of the groove structure.

[0024] Internal threads are arranged on the inner side of the side wall near one end of the bottom surface, external threads are arranged on the outer side of the base, and the internal threads are fixedly matched with the internal threads.

[0025] The side wall sleeves on a specific position on the base near one end of the bottom surface to fix the cell body.

[0026] It further includes a rotatable workbench, the base is fixed on the workbench, and the inclination angle of the workbench is adjustable. Description of the Drawings

[0027] Figure 1 is a disassembled schematic diagram of the peeling device according to an embodiment of the present invention.

[0028] Figure 2 is a top view disassembled schematic diagram of the peeling device according to an embodiment of the present invention.

[0029] Figure 3 is a top view disassembled schematic diagram of the peeling device according to an embodiment of the present invention.

[0030] Figure 4 is a schematic diagram of wet etching a sample according to an embodiment of the present invention.

[0031] Figure 5 It is a schematic diagram of the ICP etching area in an embodiment of the present invention.

[0032] Figure 6 It is a top view of the sample for wet etching in an embodiment of the present invention.

[0033] Figure 7 It is a schematic diagram of the ICP etching area in an embodiment of the present invention. Detailed implementation manners

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings of the present invention. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. The experimental methods described in the following embodiments are all conventional methods unless otherwise specified; the reagents and materials described are all available from public commercial channels unless otherwise specified.

[0035] Spatial relative terms such as "beneath", "below", "under", "above", "over", "on" etc. are used in this specification to explain the positioning of one element relative to a second element. These terms are intended to cover different orientations of the device in addition to those shown in the figures.

[0036] In addition, terms such as "first", "second" etc. are used to describe various elements, layers, regions, sections etc., and are not intended to be limiting. The use of "having", "containing", "including", "comprising" etc. are open terms indicating the presence of the stated element or feature, but do not exclude additional elements or features, unless the context clearly dictates otherwise.

[0037] The present invention provides a method for peeling a large-size epitaxial layer, a large-size epitaxial layer and a peeling device thereof, which include wafer-level peeling of a large-size nitride epitaxial film, wafer-level peeling of large-size nitride epitaxial film components, and formation of a stable hetero-integrated epitaxial wafer, etc. The peeling method provided by the present invention is arbitrary for the design of the epitaxial structure on the target layer, the specification of the bonding method, the selection of the electrolyte, and the requirements for the substrate. Moreover, the structure of the substrate surface and the bonding layer are not easily damaged by chemical and electrochemical corrosion, greatly expanding the application scope of this peeling method. And the high-efficiency wet etching method adopted in this method releases the inherent internal stress generated during the growth and preparation of the large-size nitride epitaxial film and components, improves the overall performance of the device, and expands potential application scenarios. To better implement this peeling method, the present invention also provides a peeling device suitable for this peeling method. The use of this peeling device can accurately control the isolation electrolyte, reduce the electron leakage caused by the electrodes participating in electrolysis, shorten the current transmission path between the electrodes and the corrosion peeling area, improve the current expansion uniformity, and enhance the utilization rate of electric energy.

[0038] As Figures 1 to 3 shown, the peeling device includes a base 101, a substrate placement groove is provided on the base, a growth substrate 201 is placed in the substrate placement groove, and also includes a conductive gasket 102, a sealing ring 103, and an electrochemical corrosion cell body 104. Optionally, the base 101 is fixed on a rotatable workbench 100, and the inclination angle of the workbench 100 can be adjusted as needed.

[0039] The electrochemical corrosion cell body 104 includes a side wall and a bottom surface. In one embodiment, internal threads are provided on the inner side of the lower end of the side wall, and external threads are provided on the outer wall of the base. The internal threads at the lower end of the side wall are engaged with the external threads on the outer wall of the base to fix the cell body on the base. In another embodiment, the size of the cell body is slightly larger than that of the base, and it is fixed on a specific position of the base by sleeving the lower end of the side wall on the base. Specifically, a clamping protrusion is provided on the inner side of the side wall of the cell body, and the number of clamping protrusions is selected as 3, which are evenly arranged along the circumferential direction of the side wall; clamping grooves are provided on the side wall of the base, and the number of clamping grooves is selected as 3, which are evenly arranged along the circumferential direction of the side wall of the base. The clamping protrusion slides into the clamping groove to form a clamping fit limit, fixing the cell body at a specific height on the base to ensure that the force between the bottom surface of the cell body and the sealing ring is appropriate when the cell body is fixed on the base.

[0040] A liquid containing cavity is provided on the bottom surface of the cell body, and this liquid containing cavity is used to guide the electrolyte to the area to be corroded. In one embodiment, the liquid containing cavity is provided in the central area of the bottom surface, preferably a circular groove, and there are multiple through holes at the bottom of the groove, and the through holes are evenly distributed along the bottom of the groove. In another embodiment, the liquid containing cavity is a pipe arranged in a ring shape, and the pipe is arranged in the area near the side wall on the bottom surface, and multiple through holes are evenly distributed at the bottom of the pipe.

[0041] Through holes are formed in the side wall of the cell body. One ends of the water injection pipe 105 and the drain pipe 106 pass through the through holes and are connected to the solution chamber, and the electrolyte flows into the solution chamber through the water injection pipe. The other end of the drain pipe is connected to a vacuum pump (not shown). When it is necessary to drain the electrolyte, the vacuum pump is turned on, and the electrolyte in the solution chamber is drained through the drain pipe. An opening is also formed in the side wall of the cell body, and the working electrode 107 is arranged on the inner side of the side wall along the opening. The working electrode can be a platinum sheet electrode. The counter electrode 108 is arranged along the water injection pipe and communicates with the solution chamber. Preferably, the counter electrode is a platinum wire electrode wound around the water injection pipe and communicating with the solution chamber.

[0042] When the peeling device is working, first, the base is fixed on a rotatable workbench, and the inclination angle of the workbench is adjustable. The growth substrate 201 including the heavily doped layer and the target layer is placed on the substrate placement groove. Among them, the thickness of the heavily doped layer is not less than 100 nm, and its doping concentration is at least one order of magnitude higher than that of the target layer. The target layer can be any epitaxial layer, such as a nitride epitaxial thin film or a high electron mobility transistor (HEMT) element.

[0043] A target substrate (not shown) is bonded to the growth substrate 201. The size of the target substrate is smaller than that of the growth substrate. A ring-shaped groove with a certain width and depth is arranged along the edge area of the growth substrate. The ring-shaped groove exposes the heavily doped layer, and the conductive material layer is filled in the ring-shaped groove and contacts the heavily doped layer to form a conductive ring layer. For example, the conductive ring layer can be a silver layer. The conductive gasket 102 is placed on the conductive ring layer. An etching groove is arranged on the growth substrate 201 at a certain distance from the conductive ring layer. The distance between the outer side of the etching groove and the inner ring of the conductive ring layer is not less than 1 mm. In one embodiment, the etching groove is circular and is located in the central area of the growth substrate, as Figure 4 and Figure 5 shown. The etching groove extends from the surface of the target substrate to a certain depth into the heavily doped layer. In one embodiment, the target substrate does not block the etching groove. The etching groove is close to the conductive ring layer and extends to a certain depth into the heavily doped layer, as Figure 6 and Figure 7 shown. The sealing ring 103 is placed between the conductive gasket 102 and the etching groove to prevent the electrolyte in the etching groove from flowing into the conductive ring layer area.

[0044] When the cell body 104 is detachably placed on the base 101, its bottom surface is in close contact with the sealing ring 103. The working electrode 107 is electrically connected to the conductive washer 102. The electrolyte flows into the solution chamber along the water injection pipe 105 and is injected into the corrosion groove through the through holes at the bottom of the solution chamber. The counter electrode 108 is connected to start the electrochemical corrosion. During the corrosion process, according to the corrosion situation in the corrosion groove area, the inclination angle of the workbench 100 is adjusted so that the electrolyte solution is more evenly distributed in all directions of the corrosion area, avoiding too fast corrosion rate in a certain direction in the corrosion area. After the electrochemical corrosion is completed, the remaining electrolyte is discharged through the drain pipe.

[0045] Example 1

[0046] In this example, the growth substrate is a 2-inch sapphire substrate. A heavily doped layer and a target layer located on the heavily doped layer are grown on the sapphire substrate. The heavily doped layer and the target layer are nitride epitaxial films with a doping concentration difference of 10 times. The substrate is cleaned according to the standard cleaning process and then dried.

[0047] A bonding layer of 15 nm titanium and 600 nm indium is sequentially evaporated on the surface of the target layer. Using the silicon wafer as the target substrate, annealing is carried out at 220 °C for 30 min to achieve tight bonding. In this example, the radius of the silicon wafer is smaller than that of the sapphire substrate.

[0048] The ICP etching process is selected. Along the periphery of the nitride epitaxial film, it is etched to a certain depth in the heavily doped layer to form an annular groove with a thickness and width of 1.0 μm ± 0.5 μm. The annular groove exposes the heavily doped layer. The magnetron sputtering process is used to sputter a 1500 nm ± 20 nm silver layer in the annular groove to form a conductive ring layer, which contacts the conductive washer placed on the annular groove, such as a copper washer. The copper washer is electrically connected to the working electrode platinum sheet and connected to the external circuit.

[0049] The ICP etching process is continued. In the central area of the nitride epitaxial film, it is etched along the surface of the silicon wafer to a certain depth in the heavily doped layer to form a groove area in the nitride epitaxial film with a radius of 5.0 mm ± 0.1 mm and a thickness of 1.0 μm ± 0.5 μm. A sealing ring is placed between the conductive ring layer and the groove area to prevent the electrolyte from flowing into the conductive ring layer area. A 0.3 mol / L nitric acid solution is injected into the groove area, and the flow rate of the liquid is controlled to just fill the groove area.

[0050] Ultraviolet light with a central wavelength of 365 nm and a power of 10 W is used as the auxiliary light source, and the corrosion voltage is 20 V for photo-assisted electrochemical corrosion, and the corrosion time is 10 min to 20 min.

[0051] Adjust the tilt angle of the electrolytic cell according to the corrosion condition of the central groove area, so that the electrolyte solution is more evenly distributed in all directions of the corrosion area, and avoid too fast corrosion rate in a certain direction.

[0052] After the electrochemical corrosion is completed, the sample is rinsed with deionized water and dried with nitrogen, and then an epitaxial wafer hetero-integrated on a silicon substrate can be obtained.

[0053] Example 2

[0054] In this example, a 2-inch sapphire substrate is selected as the growth substrate. A heavily doped layer and a target layer disposed on the heavily doped layer are provided on the sapphire substrate. A high electron mobility transistor (HEMT) element is disposed on the target layer. Among them, the doping concentration difference between the heavily doped layer and the target layer is 10 times. Clean and dry according to the standard cleaning process.

[0055] Deposit 15 nm of titanium and 600 nm of indium on the HEMT surface in sequence as the bonding layer. Using a silicon wafer as the target substrate, anneal at 220 °C for 30 min to achieve tight bonding. In this example, the radius of the silicon wafer is smaller than that of the sapphire substrate.

[0056] Select the ICP etching process. Along the periphery of the HEMT element, etch to a certain depth in the heavily doped layer to form an annular groove with a width of 2.0 mm ± 0.1 mm and a thickness of 1.0 μm ± 0.5 μm. The annular groove exposes the heavily doped layer. Apply silver paste in the annular groove as a conductive coating to form a conductive ring layer, and contact with a conductive washer placed on the annular groove, such as a copper washer. The copper washer is electrically connected to the working electrode platinum sheet and connected to the external circuit.

[0057] Continue to use the ICP etching process to etch and form an annular groove with a width of 5.0 mm ± 0.1 mm and a thickness of 1.0 μm ± 0.5 μm around the area 1.0 cm ± 0.1 mm inside the inner circle of the conductive ring layer. The area between the conductive ring layer and the annular groove is used to place a sealing ring to prevent the electrolyte from flowing into the conductive ring layer area. Inject 0.3 mol / L potassium sulfate solution into the annular groove and control the liquid flow rate so that it just fills the annular groove.

[0058] Use ultraviolet light with a central wavelength of 365 nm and a power of 10 W as the auxiliary light source, and carry out photo-assisted electrochemical corrosion at a corrosion voltage of 20 V. According to the corrosion condition of the annular groove area, adjust the tilt angle of the electrolytic cell every 5 min to 6 min to adjust the area where the electrolyte solution is immersed and diffused, control the sequential corrosion of different areas of the HEMT element, and finally achieve the complete peeling of the sample. The corrosion time is 30 min to 40 min.

[0059] After the electrochemical corrosion is completed, the sample is rinsed with deionized water and dried with nitrogen to obtain HEMT components hetero-integrated on a silicon wafer.

[0060] Example 3

[0061] In this example, a 2-inch sapphire substrate is selected as the growth substrate. A heavily doped layer and a target layer located on the heavily doped layer are grown on the sapphire substrate. The heavily doped layer and the target layer are nitride epitaxial films with a doping concentration difference of 10 times. The substrate is cleaned according to the standard cleaning process and then dried.

[0062] A bonding layer of 15 nm titanium and 600 nm indium is sequentially evaporated on the surface of the nitride epitaxial film. Using the silicon wafer as the target substrate, annealing is carried out at 220 °C for 30 min to achieve tight bonding. In this example, the radius of the silicon wafer is smaller than that of the sapphire substrate.

[0063] The ICP etching process is selected. Along the periphery of the nitride epitaxial film, etching is carried out to a certain depth in the heavily doped layer to form an annular groove with a width of 2.0 mm ± 0.1 mm and a thickness of 1.0 μm ± 0.5 μm. The annular groove exposes the heavily doped layer. Silver paste is applied in the annular groove as a conductive coating to form a conductive ring layer, and it contacts a conductive washer placed on the annular groove, such as a copper washer. The copper washer is electrically connected to the working electrode platinum sheet and connected to the external circuit.

[0064] The ICP etching process is continued. Etching is carried out around the area 1.0 cm ± 0.1 mm inside the inner circle of the conductive ring layer to form an annular groove with a width of 5.0 mm ± 0.1 mm and a thickness of 1.0 μm ± 0.5 μm. The area between the conductive ring layer and the annular groove is used to place a sealing ring to prevent the electrolyte from flowing into the conductive ring layer area. A 0.3 mol / L nitric acid solution is injected into the annular groove, and the liquid flow rate is controlled to just fill the annular groove.

[0065] Electrochemical corrosion is carried out at a corrosion voltage of 20 V. According to the corrosion situation in the annular groove area, the inclination angle of the electrolytic cell is adjusted every 5 min - 6 min to adjust the area immersed and diffused by the electrolyte solution, and different areas of the nitride film are controlled to be corroded in sequence, and finally the complete peeling of the sample is achieved. The corrosion time is 20 min to 30 min.

[0066] After the electrochemical corrosion is completed, the sample is rinsed with deionized water and dried with nitrogen to obtain an epitaxial wafer hetero-integrated on a silicon wafer.

[0067] Example 4

[0068] In this embodiment, a 2-inch sapphire substrate is selected as the growth substrate. A heavily doped layer is provided on the sapphire substrate, and a target layer is provided on the heavily doped layer. A high electron mobility transistor (HEMT) element is located on the target layer. Among them, the doping concentration difference between the heavily doped layer and the target layer is 10 times. Cleaning and drying are carried out according to the standard cleaning process.

[0069] On the surface of the HEMT, 15 nm of titanium and 600 nm of indium are sequentially evaporated as the bonding layer. Using a silicon wafer as the target substrate, annealing is carried out at 220 °C for 30 min to achieve tight bonding. In this embodiment, the radius of the silicon wafer is smaller than that of the sapphire substrate.

[0070] The ICP etching process is selected. Along the periphery of the edge of the HEMT element, etching is carried out to a certain depth in the heavily doped layer to form an annular groove with a thickness and width of 1.0 μm ± 0.5 μm. The annular groove exposes the heavily doped layer. The magnetron sputtering process is used to sputter a silver layer with a thickness of 100 nm ± 20 nm in the annular groove to form a conductive ring layer, which is in contact with a conductive washer placed on the annular groove, such as a copper washer. The copper washer is electrically connected to the working electrode platinum sheet and connected to an external circuit.

[0071] Continuing to use the ICP etching process, in the central region of the growth substrate, etching is carried out along the surface of the silicon wafer to a certain depth in the heavily doped layer, and a groove region with a radius of 5.0 mm ± 0.1 mm and a thickness of 1.0 μm ± 0.5 μm is etched in the central region of the HEMT element region. A sealing ring is placed between the conductive ring layer and the groove region to prevent the electrolyte from flowing into the conductive ring layer region. A 0.3 mol / L potassium sulfate solution is injected into the groove region, and the liquid flow rate is controlled to just fill the groove region.

[0072] According to the corrosion situation of the central groove region, the tilt angle of the electrolytic cell is adjusted so that the electrolyte solution is more evenly distributed in all directions of the corrosion region, avoiding too fast corrosion speed in a certain direction. The corrosion voltage is 30 V for electrochemical corrosion, and the corrosion time is 40 min to 50 min.

[0073] After the electrochemical corrosion is completed, the sample is rinsed with deionized water and dried with nitrogen, and then the HEMT element hetero-integrated on the silicon substrate can be obtained.

[0074] The peeling method and peeling device of the present invention solve the problems of rapid, efficient and uniform peeling of large-size epitaxial films and components and the formation of stable hetero-epitaxial wafers, improve the efficiency of epitaxial structure transfer and component manufacturing, reduce the cost of subsequent processing and manufacturing, have simple operation, high repeatability, and high energy utilization rate, and have broad application prospects in nitride optoelectronic devices and power devices, etc.

[0075] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for peeling a large-sized epitaxial layer, characterized in that, Including the following steps: Bonding a target substrate to a growth substrate including a heavily doped layer and a target layer; Forming a first mask layer with a first predetermined pattern on the target substrate, and etching the target layer to a certain depth into the heavily doped layer with the first mask layer as a mask to form a first groove disposed around the edge of the growth substrate; Forming a second mask layer with a second predetermined pattern on the target substrate, and etching the target layer to a certain depth into the heavily doped layer with the second mask layer as a mask to form a second groove, the first groove surrounding the second groove, and the distance between adjacent edges of the first groove and the second groove being not less than 1 mm; Forming a conductive layer in the first groove in contact with the working electrode; Injecting an appropriate amount of electrolyte solution into the second groove; Electrochemically etching the heavily doped layer to release the target layer, and obtaining the target layer hetero-integrated on the target substrate, that is, a large-size epitaxial layer.

2. The peeling method according to claim 1, wherein The second groove is located in the central region of the growth substrate.

3. The peeling method according to claim 1 or 2, characterized in that, The doping concentration of the heavily doped layer is at least one order of magnitude higher than that of the target layer; the thickness of the heavily doped layer is not less than 100 nm; the liquid level of the electrolyte solution is not higher than the heavily doped layer.

4. The peeling method according to claim 3, characterized in that When the growth substrate is selected to be 2 inches, the corrosion voltage for its electrochemical etching is 10 V to 30 V, and the corrosion time is 20 min to 50 min.

5. A large-sized epitaxial layer, characterized in that, The large-size epitaxial layer is obtained by the peeling method according to any one of claims 1 to 4.

6. A peeling device for a large-sized epitaxial layer, characterized in that, Including a base, a substrate placement groove provided on the base; an electrochemically corrosive cell body detachably fixed on the base, the cell body having a side wall and a bottom surface; a counter electrode, a working electrode, a conductive gasket, and a sealing ring; A water injection pipe and a drainage pipe are fixed on the side wall of the cell body, a solution containing cavity is provided on the bottom surface, the water injection pipe and the drainage pipe communicate with the solution containing cavity, and the counter electrode is connected to the solution containing cavity; When the peeling device works, the growth substrate is placed in the substrate placement groove, a conductive ring layer and a corrosion groove are provided on the growth substrate, the conductive gasket is placed on the conductive ring layer and is electrically connected to the working electrode, the sealing ring is placed between the conductive ring layer and the corrosion groove, the lower end of the side wall is detachably fixed on the base, the bottom surface is in contact with the sealing ring, and the electrolyte solution is injected into the solution containing cavity along the water injection pipe and flows to the corrosion groove through the solution containing cavity.

7. The peeling device according to claim 6, characterized in that The solution containing cavity is an annular pipe, and a plurality of through holes are opened at the bottom of the pipe.

8. The peeling device according to claim 6, wherein, The solution containing cavity is a groove structure, and a plurality of openings are opened at the bottom of the groove structure.

9. The peeling device according to any one of claims 6 to 8, characterized in that, Internal threads are provided on the inner side of the side wall near the bottom surface, external threads are provided on the outer side of the base, and the internal threads are fixedly matched with the internal threads.

10. The peeling device according to any one of claims 6 to 8, characterized in that, The side wall is sleeved on the base near the bottom surface and is fixed at a specific position to fix the cell body.

11. The peeling device according to any one of claims 6 to 8, characterized in that, It further includes a rotatable workbench, the base is fixed on the workbench, and the inclination angle of the workbench is adjustable.

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