Semiconductor film and preparation method and application thereof

Abstract

The invention belongs to the technical field of semiconductor film preparation, and relates to a semiconductor film and a preparation method and application thereof, and the preparation method comprises the following steps: enabling a semiconductor wafer to be in contact with the liquid level of an etchant solution, or enabling the part of the semiconductor wafer in a target stripping area to be immersed in the etchant solution for electrochemical corrosion stripping, the etchant solution climbs to the semiconductor wafer, and then the semiconductor wafer is immersed in water to obtain the semiconductor film; the semiconductor wafer is used as an anode, and the etchant solution is used as an electrolyte. According to the preparation method, the semiconductor wafer is contacted with or partially immersed in the etchant solution, so that the etchant solution climbs to the upper part of the wafer by utilizing the capillary effect, and the semiconductor film is not influenced by solution corrosion and acting force in the corrosion process because the vast majority of area of the semiconductor wafer is not in direct contact with the etchant solution; therefore, a semiconductor film which is large in area, high in regularity and basically free of surface damage can be stripped at the wafer level.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor film preparation, and relates to a semiconductor film and a preparation method and application thereof. Background Art

[0002] Semiconductor thin films are widely used in electronic devices, photovoltaic devices, sensors and optoelectronic devices. For example, gallium nitride is a wide bandgap semiconductor material with excellent material properties such as direct bandgap and high electron mobility. Gallium nitride thin films have been widely used in optoelectronic devices (such as LEDs, detectors and sensors).

[0003] The method for preparing semiconductor thin films is generally electrochemical wet etching and stripping, which mainly uses electrochemical principles. For example, when preparing gallium nitride thin films, free carriers (holes) are introduced into the gallium nitride wafer by applying voltage, making it easy to corrode in electrolytes (such as hydrofluoric acid, oxalic acid, nitric acid and potassium hydroxide). Among them, the gallium nitride wafer serves as the anode, and by applying a bias voltage, electron-hole pairs are excited. The holes participate in the oxidation reaction of gallium nitride and destroy the structure of gallium nitride, thereby achieving corrosion stripping and obtaining a gallium nitride film.

[0004] The development of electrochemical wet etching stripping technology is mainly focused on increasing the film area, improving the film surface quality and expanding the scope of application. At present, in the wafer-level (2-inch) size etching process, the stripped semiconductor film is fully immersed in the liquid during the etching process, resulting in the continuous corrosion and force erosion of the semiconductor film surface by the liquid; in addition, the process of removing the film from the solution is very susceptible to external stress. These unavoidable factors can easily lead to the breakage of the film, so that only semiconductor films with too small an area, poor regularity and more surface damage can be obtained.

[0005] Based on the above research, it is necessary to provide a method for preparing a semiconductor thin film, which can obtain a semiconductor thin film with a large area, high regularity and basically no surface damage. Summary of the invention

[0006] The object of the present invention is to provide a semiconductor film and a preparation method and application thereof. The preparation method only requires that the semiconductor wafer be in contact with or partially immersed in a corrosion solution, so that the corrosion solution climbs above the wafer using a capillary effect. Since most areas of the semiconductor wafer are not in direct contact with the corrosion solution, the semiconductor film will not be affected by the corrosion and force of the solution during the corrosion process, thereby being able to peel off a large-area, high-regularity, and substantially surface-damaged semiconductor film at the wafer level.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a method for preparing a semiconductor thin film, the method comprising the following steps:

[0009] The semiconductor wafer is brought into contact with the liquid surface of the etching solution, or the semiconductor wafer portion of the target stripping area is partially immersed in the etching solution for electrochemical etching stripping, the etching solution climbs onto the semiconductor wafer, and then the semiconductor wafer is immersed in water to obtain the semiconductor film.

[0010] The electrochemical corrosion stripping system includes an anode, a cathode and an electrolyte, the semiconductor wafer serves as the anode, and the corrosion solution serves as the electrolyte.

[0011] The present invention utilizes the capillary effect and only needs to contact the semiconductor wafer with the liquid surface of the etching solution, or immerse a part of the semiconductor wafer in the etching solution for electrochemical etching stripping, so that the etching solution can utilize the capillary effect to climb onto the semiconductor wafer that is not in contact with the etching solution, thereby avoiding the problem that when the semiconductor wafer is fully immersed in the etching solution, the semiconductor film is affected by the etching solution, resulting in the semiconductor film having a small area, poor regularity and more surface damage. Therefore, since the partial area of ​​the semiconductor wafer described in the present invention is not in direct contact with the etching solution, the semiconductor film will not be affected by the corrosion and force of the solution during the etching process, so that a semiconductor film with a large area, high regularity and basically no surface damage can be stripped at the wafer level.

[0012] The present invention partially immerses the semiconductor wafer in the target stripping area. For example, when the target stripping area accounts for 90% of the semiconductor wafer, a part of the 90% area is immersed in the corrosion solution, and there is no need to immerse the entire target stripping area in the corrosion solution; wherein, the present invention does not make specific limitations on the target stripping area, for example, the volume accounts for more than 90% of the entire semiconductor wafer.

[0013] After the etching solution of the present invention utilizes the capillary effect to climb and peel off the semiconductor wafer, the semiconductor wafer is directly immersed in water (deionized water or high-purity water) to directly obtain a semiconductor thin film.

[0014] Preferably, the volume of the semiconductor wafer below the liquid surface of the corrosive solution accounts for 0-10% of the volume of the entire semiconductor wafer, for example, it can be 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] When the volume of the semiconductor wafer below the liquid surface of the etching solution accounts for 0% of the volume of the entire semiconductor wafer, the semiconductor wafer is in contact with the liquid surface of the etching solution.

[0016] In order to avoid the problem of damage to the semiconductor film caused by direct contact between the etching solution and the semiconductor wafer to the greatest extent, the present invention preferably allows the volume of the semiconductor wafer below the etching solution surface to account for 0-10% of the volume of the entire semiconductor wafer. If the proportion of the semiconductor wafer below the etching solution surface is too high, the quality of the obtained semiconductor film will decrease.

[0017] Preferably, the diameter of the semiconductor wafer is 50 mm, 75 mm or 100 mm.

[0018] Preferably, the semiconductor wafer below the liquid level of the etching solution is 0-5 mm away from the liquid level, for example, 0 mm, 1 mm, 2 mm, 3 mm, 4 mm or 5 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] When the semiconductor wafer below the liquid surface of the etching solution is 0 mm away from the liquid surface, the semiconductor wafer is in contact with the liquid surface of the etching solution.

[0020] The semiconductor wafer below the liquid surface of the etching solution of the present invention is 0-5 mm away from the liquid surface, which refers to the straight-line distance perpendicular to the liquid surface from the farthest end of the semiconductor wafer below the liquid surface.

[0021] Preferably, the semiconductor wafer comprises a substrate, a semiconductor material conducting layer, a semiconductor material isolating layer, a semiconductor material sacrificial layer and a semiconductor material target layer which are stacked in sequence;

[0022] The doping concentration of the semiconductor material sacrificial layer is greater than the doping concentration of the semiconductor material conductive layer.

[0023] The semiconductor wafer described in the present invention includes a specific layered structure, wherein the semiconductor material target layer is the semiconductor film finally obtained by peeling off, and the semiconductor material sacrificial layer will be corroded during electrochemical corrosion stripping, so that the semiconductor material target layer can be stripped off; the semiconductor material conductive layer is used to make the voltage evenly distributed during the electrochemical corrosion stripping process and will not be corroded and stripped off; the semiconductor material isolation layer is to prevent the semiconductor material conductive layer from being corroded.

[0024] When performing electrochemical corrosion stripping, the voltage of the electrochemical corrosion stripping will be selective to the doping concentration of each layer in the semiconductor wafer. The present invention ensures that the doping concentration of the sacrificial layer of the semiconductor material is greater than the doping concentration of the conductive layer of the semiconductor material, so that the doping concentration of the sacrificial layer of the semiconductor material is the highest, ensuring that only the sacrificial layer of the semiconductor material is corroded without corroding other layers.

[0025] Preferably, the semiconductor material target layer is a non-doped semiconductor material layer, and the doping concentration of the semiconductor material sacrificial layer is 1×10 19 cm-3 above (for example, it can be 1×10 19 cm -3 , 5×10 19 cm -3 or 1×10 20 cm -3 ), the doping concentration of the semiconductor material conductive layer is 1×10 18 cm -3 above (for example, it can be 1×10 18 cm -3 , 5×10 18 cm -3 or 1×10 19 cm -3 ), but it is necessary to ensure that the doping concentration of the semiconductor material sacrificial layer is greater than the doping concentration of the semiconductor material conductive layer. Preferably, the doping concentration of the semiconductor material sacrificial layer is more than 5 times the doping concentration of the semiconductor material conductive layer, but not too close, for example, it can be 5 times, 10 times, 15 times or 20 times; wherein, the doping elements of the semiconductor material sacrificial layer and the semiconductor material conductive layer can exemplarily be silicon.

[0026] Preferably, the semiconductor wafer further includes a buffer layer, and the buffer layer is located between the substrate and the semiconductor material conductive layer.

[0027] Preferably, the semiconductor material in the semiconductor wafer includes any one of GaN, AlGaN, AlN or ZnO, or a combination of at least two of them.

[0028] The preparation method of the present invention can be used with a variety of semiconductor materials, such as GaN, AlGaN, AlN or ZnO, and can even be used to peel off already manufactured devices, and can be applied in the field of flexible devices.

[0029] Preferably, the voltage of the electrochemical corrosion stripping is above 16V, for example, it can be 16V, 18V, 20V, 22V, 24V, 26V, 28V or 30V, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] The voltage applied during the electrochemical corrosion stripping of the present invention is preferably above 16V, which promotes the corrosion solution to climb above the semiconductor wafer.

[0031] Preferably, the temperature of the electrochemical corrosion stripping is 15-25°C, for example, 15°C, 20°C or 25°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0032] The present invention does not specifically limit the time of the electrochemical corrosion stripping. Those skilled in the art can adjust it adaptively according to the needs. Exemplarily, it can be 50-80 minutes, such as 50 minutes, 60 minutes, 70 minutes or 80 minutes, but it is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0033] Preferably, the etching solution comprises any one of HF, KOH, oxalic acid or nitric acid, or a combination of at least two thereof.

[0034] Preferably, the concentration of the corrosive solution is 0.1-1.5 mol / L, for example, it can be 0.1 mol / L, 0.3 mol / L, 0.5 mol / L, 0.7 mol / L, 0.9 mol / L, 1.1 mol / L, 1.3 mol / L or 1.5 mol / L, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] Preferably, the cathode comprises a platinum electrode.

[0036] In a second aspect, the present invention provides a semiconductor thin film, which is prepared by the preparation method described in the first aspect.

[0037] In a third aspect, the present invention provides an application of the semiconductor film as described in the second aspect, wherein the application includes using the semiconductor film in an optoelectronic device.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The present invention brings the semiconductor wafer into contact with the liquid surface of a corrosive solution, or immerses a portion of the semiconductor wafer in a corrosive solution for electrochemical corrosion stripping, and utilizes a capillary effect to cause the corrosive solution to climb onto the semiconductor wafer that is not in contact with the corrosive solution, thereby avoiding the problem that when the semiconductor wafer is completely immersed in the corrosive solution, the semiconductor film is affected by the corrosive solution, resulting in a small area of ​​the semiconductor film, poor regularity, and more surface damage. As a result, a semiconductor film with a large area, high regularity, and substantially no surface damage can be stripped at the wafer level. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a flow chart of the preparation method described in Example 1 of the present invention.

[0041] Figure 2 This is a schematic diagram of the structure of the electrochemical corrosion device described in Example 1 of the present invention.

[0042] Among them, 1-gallium nitride wafer, 2-electrode clamp, 3-platinum electrode, 4-corrosion solution. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0044] Example 1

[0045] This embodiment provides a method for preparing a semiconductor thin film. The flowchart of the method is as follows: Figure 1 As shown, the preparation method comprises the following steps:

[0046] (1) According to Figure 2 The electrochemical etching device is constructed as shown, wherein the gallium nitride wafer 1 is partially immersed in the etching solution, the gallium nitride wafer 1 is the anode, and one side of the gallium nitride wafer 1 ( Figure 2 The area above the horizontal line of the silicon nitride wafer 1, which accounts for 10% of the wafer volume, and the area below the horizontal line, which accounts for 90% of the wafer volume, is silver-plated as the target stripping area, and then an electrode clamp 2 is set to connect to a power supply, the platinum electrode 3 is an anode connected to the power supply, and the corrosion solution 4 is an electrolyte.

[0047] The gallium nitride wafer 1 comprises a sapphire substrate, a gallium nitride buffer layer, a gallium nitride conductive layer, a gallium nitride isolation layer, a gallium nitride sacrificial layer and a gallium nitride target layer which are stacked in sequence; the gallium nitride buffer layer is a gallium nitride layer with a thickness of 1 μm; the gallium nitride conductive layer is a gallium nitride layer with a doping concentration of 10 18 cm -3 The doped gallium nitride layer is 500 nm thick; the gallium nitride isolation layer is a non-doped gallium nitride layer with a thickness of 500 nm; the gallium nitride sacrificial layer is a doping concentration of 10 19 cm -3 The doped gallium nitride layer has a thickness of 1.25 μm; the gallium nitride target layer is a non-doped gallium nitride layer with a thickness of 300 nm.

[0048] The corrosion solution is a dilute nitric acid solution with a concentration of 1 mol / L.

[0049] (2) The gallium nitride wafer is a 2-inch wafer with a radius of 50 mm, which is partially immersed in the etching solution. The volume of the semiconductor wafer below the etching solution liquid level accounts for 3% of the volume of the entire semiconductor wafer. At 20°C, a voltage of 20 V is applied for 1.5 hours. The etching solution 4 will flow along Figure 2 As shown by the arrow in the figure, the gallium nitride wafer 1 climbs up. After the electrochemical corrosion stripping is completed, the gallium nitride wafer 1 is immersed in deionized water, and the gallium nitride film is automatically stripped to obtain the semiconductor film.

[0050] Example 2

[0051] This embodiment provides a method for preparing a semiconductor thin film, the method comprising the following steps:

[0052] (1) Building an electrochemical corrosion device, wherein a gallium nitride wafer is partially immersed in a corrosion solution, the gallium nitride wafer is an anode, one side of the gallium nitride wafer is silver-plated, and then an electrode clamp is set to connect to a power supply, the platinum electrode is an anode connected to the power supply, and the corrosion solution is an electrolyte.

[0053] The gallium nitride wafer comprises a sapphire substrate, a gallium nitride buffer layer, a gallium nitride conductive layer, a gallium nitride isolation layer, a gallium nitride sacrificial layer and a gallium nitride target layer which are stacked in sequence; the gallium nitride buffer layer is a gallium nitride layer with a thickness of 1 μm; the gallium nitride conductive layer is a gallium nitride layer with a doping concentration of 10 18 cm -3 The doped gallium nitride layer is 500 nm thick; the gallium nitride isolation layer is a non-doped gallium nitride layer with a thickness of 500 nm; the gallium nitride sacrificial layer is a doping concentration of 10 19 cm -3 The doped gallium nitride layer has a thickness of 1.25 μm; the gallium nitride target layer is a non-doped gallium nitride layer with a thickness of 300 nm.

[0054] The corrosion solution is a dilute nitric acid solution with a concentration of 1.5 mol / L.

[0055] (2) The gallium nitride wafer is a 2-inch wafer with a radius of 50 mm. The area accounting for 90% of the wafer volume is the target stripping area. The gallium nitride wafer portion in the target area is immersed in a corrosion solution. The volume of the semiconductor wafer below the liquid surface of the corrosion solution accounts for 6% of the volume of the entire semiconductor wafer. At 25°C, a voltage of 25 V is applied for 2 hours. The corrosion solution will climb onto the gallium nitride wafer. After the electrochemical corrosion stripping is completed, the gallium nitride wafer is immersed in deionized water. The gallium nitride film is automatically stripped to obtain the semiconductor film.

[0056] Example 3

[0057] This embodiment provides a method for preparing a semiconductor thin film, the method comprising the following steps:

[0058] (1) Building an electrochemical corrosion device, wherein a gallium nitride wafer is partially immersed in a corrosion solution, the gallium nitride wafer is an anode, one side of the gallium nitride wafer is silver-plated, and then an electrode clamp is set to connect to a power supply, the platinum electrode is an anode connected to the power supply, and the corrosion solution is an electrolyte.

[0059] The gallium nitride wafer comprises a sapphire substrate, a gallium nitride buffer layer, a gallium nitride conductive layer, a gallium nitride isolation layer, a gallium nitride sacrificial layer and a gallium nitride target layer which are stacked in sequence; the gallium nitride buffer layer is a gallium nitride layer with a thickness of 1 μm; the gallium nitride conductive layer is a gallium nitride layer with a doping concentration of 10 19 cm -3 The doped gallium nitride layer is 500 nm thick; the gallium nitride isolation layer is a non-doped gallium nitride layer with a thickness of 500 nm; the gallium nitride sacrificial layer is a doping concentration of 10 20 cm -3 The doped gallium nitride layer has a thickness of 1.25 μm; the gallium nitride target layer is a non-doped gallium nitride layer with a thickness of 300 nm.

[0060] The corrosion solution is a dilute nitric acid solution with a concentration of 0.5 mol / L.

[0061] (2) The gallium nitride wafer is a 2-inch wafer with a radius of 50 mm. The area accounting for 90% of the wafer volume is the target stripping area. The gallium nitride wafer portion in the target area is immersed in a corrosion solution. The volume of the semiconductor wafer below the liquid surface of the corrosion solution accounts for 9% of the volume of the entire semiconductor wafer. At 15°C, a voltage of 16 V is applied for 2.5 hours. The corrosion solution will climb onto the gallium nitride wafer. After the electrochemical corrosion stripping is completed, the gallium nitride wafer is immersed in deionized water. The gallium nitride film is automatically stripped to obtain the semiconductor film.

[0062] Example 4

[0063] This embodiment provides a method for preparing a semiconductor thin film, the method comprising the following steps:

[0064] (1) Building an electrochemical corrosion device, wherein the gallium nitride wafer is in contact with the liquid surface of the corrosion solution, the gallium nitride wafer is an anode, one side of the gallium nitride wafer is silver-plated, and then an electrode clamp is set to connect to a power supply, the platinum electrode is an anode connected to the power supply, and the corrosion solution is an electrolyte.

[0065] The gallium nitride wafer comprises a sapphire substrate, a gallium nitride buffer layer, a gallium nitride conductive layer, a gallium nitride isolation layer, a gallium nitride sacrificial layer and a gallium nitride target layer which are stacked in sequence; the gallium nitride buffer layer is a gallium nitride layer with a thickness of 1 μm; the gallium nitride conductive layer is a gallium nitride layer with a doping concentration of 10 18 cm -3 The doped gallium nitride layer is 500 nm thick; the gallium nitride isolation layer is a non-doped gallium nitride layer with a thickness of 500 nm; the gallium nitride sacrificial layer is a doping concentration of 10 19 cm -3 The doped gallium nitride layer has a thickness of 1.25 μm; the gallium nitride target layer is a non-doped gallium nitride layer with a thickness of 300 nm.

[0066] The corrosion solution is a dilute nitric acid solution with a concentration of 1.5 mol / L.

[0067] (2) The gallium nitride wafer is a 2-inch wafer with a radius of 50 mm. It is in contact with a corrosion solution. At 25°C, a voltage of 20 V is applied for 2 hours. The corrosion solution will climb onto the gallium nitride wafer. After the electrochemical corrosion stripping is completed, the gallium nitride wafer is immersed in deionized water. The gallium nitride film is automatically stripped to obtain the semiconductor film.

[0068] Example 5

[0069] This embodiment provides a method for preparing a semiconductor thin film. The preparation method is the same as that of Embodiment 2 except that an aluminum nitride wafer is used instead of a gallium nitride wafer, and an aluminum nitride thin film is obtained by peeling.

[0070] Example 6

[0071] This embodiment provides a method for preparing a semiconductor thin film, which is the same as that of Embodiment 1 except that the volume of the semiconductor wafer below the liquid surface of the etching solution accounts for 50% of the volume of the entire semiconductor wafer.

[0072] Example 7

[0073] This embodiment provides a method for preparing a semiconductor thin film, which is the same as that of Embodiment 1 except that the volume of the semiconductor wafer below the liquid surface of the etching solution accounts for 75% of the volume of the entire semiconductor wafer.

[0074] Comparative Example 1

[0075] This comparative example provides a method for preparing a semiconductor thin film, which is the same as Example 1 except that the gallium nitride wafer in the target stripping area is completely immersed in the etching solution, that is, the volume of the semiconductor wafer below the liquid surface of the etching solution accounts for 90% of the volume of the entire semiconductor wafer.

[0076] The integrity and surface area of ​​the semiconductor films obtained in the above embodiments and comparative examples are shown in Table 1; wherein the integrity is calculated as follows: the surface area of ​​the actual peeled complete film / the surface area of ​​the wafer. The diameter of a 2-inch wafer is 5 cm, and the surface area is approximately 19.6 cm 2 .

[0077] Table 1

[0078]

[0079] From Table 1 we can see that:

[0080] It can be seen from Examples 1-7 and Comparative Example 1 that the present invention contacts the semiconductor wafer with the liquid surface of the corrosive solution, or partially immerses it in the corrosive solution for electrochemical corrosion stripping, so as to obtain a semiconductor film with a large area, high regularity and basically no surface damage; it can be seen from Examples 1-3 and Example 4 that the present invention can also achieve semiconductor film stripping by only contacting the semiconductor wafer with the liquid surface of the corrosive solution; it can be seen from Example 1 and Example 5 that the preparation method of the present invention is applicable to wafers of various semiconductor materials; it can be seen from Examples 1 and Examples 6-7 that the present invention does not immerse too many semiconductor wafers in the corrosive solution, so as to avoid the corrosive solution causing damage to the semiconductor film, thereby reducing the integrity of the semiconductor film.

[0081] In summary, the present invention provides a semiconductor film and a preparation method and application thereof. The preparation method only requires that the semiconductor wafer be in contact with or partially immersed in a corrosion solution, so that the corrosion solution climbs above the wafer using a capillary effect. Since most areas of the semiconductor wafer are not in direct contact with the corrosion solution, the semiconductor film will not be affected by the corrosion and force of the solution during the corrosion process, thereby being able to peel off a large-area, high-regularity, and essentially surface-damaged semiconductor film at the wafer level.

[0082] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a semiconductor thin film, characterized in that: The preparation method comprises the following steps: The semiconductor wafer is brought into contact with the liquid surface of the etching solution, or the semiconductor wafer portion of the target stripping area is partially immersed in the etching solution for electrochemical etching stripping, the etching solution climbs up the semiconductor wafer, and then the semiconductor wafer is immersed in water to obtain the semiconductor thin film; The electrochemical corrosion stripping system includes an anode, a cathode and an electrolyte, the semiconductor wafer serves as the anode, and the corrosion solution serves as the electrolyte.

2. The method for preparing a semiconductor thin film according to claim 1, characterized in that: The volume of the semiconductor wafer below the liquid surface of the corrosive solution accounts for 0-10% of the volume of the entire semiconductor wafer. When the volume of the semiconductor wafer below the liquid surface of the corrosive solution accounts for 0% of the volume of the entire semiconductor wafer, the semiconductor wafer is in contact with the liquid surface of the corrosive solution.

3. The method for preparing a semiconductor thin film according to claim 1, characterized in that: The diameter of the semiconductor wafer is 50 mm, 75 mm or 100 mm; And / or, the semiconductor wafer below the liquid surface of the corrosive solution is 0-5 mm away from the liquid surface; when the semiconductor wafer below the liquid surface of the corrosive solution is 0 mm away from the liquid surface, the semiconductor wafer is in contact with the liquid surface of the corrosive solution.

4. The method for preparing a semiconductor thin film according to any one of claims 1 to 3, characterized in that: The semiconductor wafer comprises a substrate, a semiconductor material conducting layer, a semiconductor material isolating layer, a semiconductor material sacrificial layer and a semiconductor material target layer which are stacked in sequence; The doping concentration of the semiconductor material sacrificial layer is greater than the doping concentration of the semiconductor material conductive layer.

5. The method for preparing a semiconductor thin film according to claim 4, characterized in that: The semiconductor wafer also includes a buffer layer, which is located between the substrate and the semiconductor material conductive layer.

6. The method for preparing a semiconductor thin film according to any one of claims 1 to 3, characterized in that: The semiconductor material in the semiconductor wafer includes any one of GaN, AlGaN, AlN or ZnO or a combination of at least two of them.

7. The method for preparing a semiconductor thin film according to any one of claims 1 to 3, characterized in that: The voltage of the electrochemical corrosion stripping is above 16V; And / or, the temperature of the electrochemical corrosion stripping is 15-25°C.

8. The method for preparing a semiconductor thin film according to any one of claims 1 to 3, characterized in that: The corrosion solution includes any one of HF, KOH, oxalic acid or nitric acid, or a combination of at least two thereof; And / or, the concentration of the corrosive solution is 0.1-1.5 mol / L; And / or, the cathode comprises a platinum electrode.

9. A semiconductor thin film, characterized in that: The semiconductor thin film is prepared by the preparation method according to any one of claims 1 to 8.

10. An application of the semiconductor film as claimed in claim 9, characterized in that: The applications include the use of semiconductor thin films in optoelectronic devices.

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