Patterned film material transfer method based on soluble sacrificial layer

Abstract

The invention discloses a patterned film material transfer method based on a soluble sacrificial layer, and belongs to the technical field of transistor construction processes. The method provided by the invention is simple to operate, the aqueous solution is used as the etching solution of the soluble sacrificial layer to etch the sacrificial layer without damaging the finally required target thin film material, and meanwhile, after the soluble sacrificial layer is etched, the organic supporting layer bearing the patterned thin film material automatically floats to the water surface, so that the etching efficiency of the patterned thin film material is improved. Extra man-made stress does not need to be introduced, and the transfer success rate is high. According to the method, favorable conditions can be provided for transfer scale expansion by depositing the large-area uniform soluble sacrificial layer. In addition, the method is matched with a low-temperature thin film deposition method, patterning transfer of the thin film material can be carried out while the large scale is considered, and the problems that an existing large-scale patterned thin film material transfer technology is low in success rate and serious in damage, and large-scale transfer and patterning transfer cannot be met at the same time are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of transistor construction process, and in particular relates to a patterned thin film material transfer method based on a soluble sacrificial layer. Background Art

[0002] The carrier mobility of two-dimensional semiconductor materials exceeding that of silicon at sizes below 5nm brings new possibilities for miniaturization of transistors. The extremely thin thickness makes it show extraordinary tunability in external electric fields, and the excellent gate controllability makes it a candidate channel material that is expected to surpass bulk silicon in future field effect transistors.

[0003] However, in the construction process of two-dimensional transistors, the direct deposition of dielectric layers without dangling bonds on the surface of two-dimensional semiconductor materials leads to uneven, island-like or non-dense pinhole shapes, and the direct deposition of metal electrodes leads to Fermi level pinning, which seriously affects the electrical performance of field-effect transistors with two-dimensional semiconductor materials as channels. Existing transfer methods will introduce too much artificial stress during the transfer process, causing cracking and damage of thin film materials. In addition, these transfer methods still have problems such as low transfer success rate, insufficient transfer scale, and inability to transfer in a patterned manner, which are obviously incompatible with the construction process of large-scale transistor arrays. Therefore, it is urgent to develop a method with high success rate and low damage that can be used for large-scale transfer of patterned thin film materials. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a patterned thin film material transfer method based on a soluble sacrificial layer.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a method for transferring a patterned thin film material based on a soluble sacrificial layer, comprising the following steps:

[0007] (1) After cleaning the substrate, a soluble sacrificial layer material is deposited on the substrate to form a soluble sacrificial layer;

[0008] (2) spin coating an exposure glue on the surface of the soluble sacrificial layer described in step (1), and then patterning the exposure glue on the surface of the soluble sacrificial layer by exposure and development to form a patterned exposure glue layer;

[0009] (3) depositing a thin film material on the surface of the patterned exposed adhesive layer described in step (2), and then performing a debonding process to obtain a patterned thin film material;

[0010] (4) spin coating an organic support layer on the surface of the patterned thin film material obtained in step (3), and then placing the organic support layer in an etching aqueous solution to etch the soluble sacrificial layer to obtain an organic support layer carrying the patterned thin film material;

[0011] (5) The organic support layer carrying the patterned thin film material obtained in step (4) is accurately transferred to the target position to achieve large-scale transfer of the patterned thin film material.

[0012] Technical principle:

[0013] The method provided by the present invention is simple to operate, and uses an aqueous solution as an etching solution for the soluble sacrificial layer. While etching the sacrificial layer, it ensures that the target thin film material required in the end is not damaged. At the same time, after the soluble sacrificial layer is etched, the organic support layer carrying the patterned thin film material automatically floats to the water surface, and no additional artificial stress needs to be introduced, and the transfer success rate is high. The present invention can provide favorable conditions for the expansion of the transfer scale by depositing a large area of ​​uniform soluble sacrificial layer. In addition, the present invention cooperates with a low-temperature thin film deposition method, and can perform patterned transfer of thin film materials while taking into account large-scale, solving the problems of low success rate, serious damage, and inability to simultaneously meet large-scale transfer and patterned transfer in the current large-scale transfer of patterned thin film materials.

[0014] Preferably, in step (1), the cleaning process is ultrasonic cleaning with deionized water, acetone and isopropanol for 3 to 5 minutes each.

[0015] Preferably, in step (1), the substrate is selected from one of an insulating silicon substrate, a strontium titanate substrate, a sapphire substrate, a pure silicon substrate, a silicon oxide substrate, a gallium arsenide substrate, a silicon carbide substrate, a gallium nitride substrate, a magnesium oxide substrate, a glass substrate, a polycrystalline silicon substrate, an amorphous oxide substrate, a PET flexible substrate and a PI flexible substrate.

[0016] Preferably, in step (1), the soluble sacrificial layer material is selected from one or more of strontium aluminate, glucose, carboxymethyl cellulose, polyethylene glycol, polyvinyl alcohol, gelatin, alginate, and chitosan.

[0017] Preferably, in step (1), the thickness of the soluble sacrificial layer is 1-100 nm, and the surface roughness Ra of the soluble sacrificial layer is ≤0.8 nm.

[0018] Preferably, in step (3), the deposition temperature of the deposited thin film material is 25 to 400° C.; the thin film material is selected from a crystalline material or an amorphous material; the deposition thickness of the deposited thin film material is 5 to 100 nm, and the surface roughness of the thin film layer obtained by depositing the thin film material is Ra≤0.8 nm.

[0019] Preferably, in step (4), the material of the organic support layer is selected from one or more of PMMA, PPC, and PVA; the number of spin-coated layers is 1 to 4 layers, the baking temperature after spin coating is 80 to 150° C., and the single baking time is 1 to 3 minutes.

[0020] Preferably, in step (4), the etching aqueous solution is selected from one or more of deionized water, acidic aqueous solution, alkaline aqueous solution, and neutral aqueous solution; and the etching time is ≤60 min.

[0021] Preferably, the specific operation of step (5) is as follows:

[0022] S1. Using PDMS, the organic support layer carrying the patterned thin film material floating in the etching aqueous solution is fished out, and one side of the patterned thin film material is exposed to the air;

[0023] S2, using a precise transfer platform to position the organic support layer carrying the patterned thin film material in step S1 directly above the target device area;

[0024] S3, the PDMS is lowered until the organic support layer carrying the patterned thin film material contacts the target substrate, and the PDMS is lifted after heating at 50-130°C for 2-3 minutes to complete the transfer.

[0025] Preferably, the deposition method of the soluble sacrificial layer material in step (1) or the thin film material in step (3) is selected from magnetron sputtering, thermal evaporation, electron beam evaporation, atomic layer deposition, pulsed laser deposition, molecular beam epitaxy, sol-gel method, chemical vapor deposition, plasma enhanced chemical vapor deposition, and metal organic chemical vapor deposition.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] Existing methods for transferring thin film materials usually rely on artificial peeling of the support layer to transfer the target material, which inevitably introduces additional stress, causing the material to be damaged to varying degrees, and the transfer success rate is low. In addition, even if there are other sacrificial layers to assist in the transfer, it is impossible to achieve high-success-rate patterning and large-area transfer due to its own process limitations. The present invention addresses the problems of low success rate and inability to pattern on a large scale in the transfer process of thin film materials applied to two-dimensional materials. A soluble material is used as a sacrificial layer, which is used as a growth substrate for the thin film material and an auxiliary layer for transfer, and a low-temperature deposition method is used to achieve a high-success-rate, low-damage transfer of large-area patterned thin film materials. At the same time, the method is compatible with large-scale transistor construction processes at the wafer level.

[0028] The patterned thin film material transfer method provided by the present invention can realize continuous expansion of the transfer scale, reaching wafer-level or even larger area transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 It is a process flow chart of the patterned thin film material transfer method based on the soluble sacrificial layer in Examples 1 and 2 of the present invention;

[0031] Figure 2 The AFM surface morphology image (a) and thickness characterization image (b) of the SAO layer in step (2) of Example 1 of the present invention;

[0032] Figure 3 The optical microscope images are of the SAO layer deposited in step (2) of Example 1 of the present invention and then placed obliquely in water for partial etching, wherein Figure a is magnified 50 times, Figure b is magnified 100 times, and Figure c is magnified 200 times;

[0033] Figure 4 This is an optical microscopic image of the patterned hafnium oxide thin film material fished out of the PDMS in step (5) of Example 1 of the present invention;

[0034] Figure 5 The actual image (a) after the patterned hafnium oxide thin film material is transferred to the target area of ​​the transistor device in step (5) of Example 1 and the electrical performance of the transistor device before and after the patterned hafnium oxide thin film material is transferred (b);

[0035] Figure 6 The schematic diagram (a), optical micrograph (b) and electrical transfer curve diagram (c) of a dual-gate transistor device constructed using the van der Waals contact top gate dielectric layer obtained in step (5) of Example 1 are shown. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] An embodiment of the present invention provides a method for transferring a patterned thin film material based on a soluble sacrificial layer, comprising the following steps:

[0039] (1) After cleaning the substrate, a soluble sacrificial layer material is deposited on the substrate to form a soluble sacrificial layer;

[0040] (2) spin coating an exposure glue on the surface of the soluble sacrificial layer described in step (1), and then patterning the exposure glue on the surface of the soluble sacrificial layer by exposure and development to form a patterned exposure glue layer;

[0041] (3) depositing a thin film material on the surface of the patterned exposed adhesive layer described in step (2), and then performing a debonding process to obtain a patterned thin film material;

[0042] (4) spin coating an organic support layer on the surface of the patterned thin film material obtained in step (3), and then placing the organic support layer in an etching aqueous solution to etch the soluble sacrificial layer to obtain an organic support layer carrying the patterned thin film material;

[0043] (5) The organic support layer carrying the patterned thin film material obtained in step (4) is accurately transferred to the target position to achieve large-scale transfer of the patterned thin film material.

[0044] In a preferred embodiment, in step (1), the substrate includes but is not limited to one of an insulating silicon substrate, a strontium titanate substrate, a sapphire substrate, a pure silicon substrate, a silicon oxide substrate, a gallium arsenide substrate, a silicon carbide substrate, a gallium nitride substrate, a magnesium oxide substrate, a glass substrate, a polycrystalline silicon substrate, an amorphous oxide substrate, a PET flexible substrate and a PI flexible substrate; illustratively, the substrate is further preferably one of a silicon oxide substrate, a titanium oxide-terminated strontium titanate substrate, a sapphire substrate and a glass substrate.

[0045] In a preferred embodiment, in step (1), the cleaning process is to use deionized water, acetone and isopropanol for ultrasonic cleaning for 3 to 5 minutes each. The present invention removes silicon slag generated on the silicon wafer during the cutting process and impurities such as organic matter attached to the surface of the silicon wafer by cleaning to obtain a clean target substrate.

[0046] In a preferred embodiment, in step (1), the soluble sacrificial layer material includes, but is not limited to, one or more of strontium aluminate, glucose, carboxymethyl cellulose, polyethylene glycol, polyvinyl alcohol, gelatin, alginate, and chitosan. The above-mentioned soluble sacrificial layer materials have good solubility in aqueous solution, and can be removed by aqueous solution in the subsequent process. At the same time, the organic support layer carrying the patterned thin film material automatically floats to the water surface, so there is no need to introduce additional artificial stress, which improves the transfer success rate and avoids damage to the thin film material. At the same time, for two-dimensional materials without dangling bonds, the above-mentioned soluble sacrificial layer materials can provide favorable conditions for the deposition of thin film materials.

[0047] In a preferred embodiment, the strontium aluminate contains SrO and Al 2 O 3 The molar ratio is 3:1.

[0048] In a preferred embodiment, the soluble sacrificial layer materials can be combined in different proportions.

[0049] In a preferred embodiment, in step (1), the thickness of the soluble sacrificial layer is 1-100 nm, more preferably 30-100 nm; the surface roughness Ra of the soluble sacrificial layer is ≤ 0.8 nm. The good surface flatness of the soluble sacrificial layer is conducive to obtaining better surface properties of the next deposited thin film.

[0050] In a preferred embodiment, in step (1), the deposition method of the soluble sacrificial layer material includes but is not limited to one of magnetron sputtering, thermal evaporation, electron beam evaporation, atomic layer deposition, pulsed laser deposition, molecular beam epitaxy, sol-gel method, chemical vapor deposition, plasma enhanced chemical vapor deposition, and metal organic chemical vapor deposition. The present invention adopts the above deposition method to achieve large-area uniform growth of the soluble sacrificial layer material, and the formed soluble sacrificial layer has good crystallinity.

[0051] In a preferred embodiment, in step (1), the deposition conditions for depositing the soluble sacrificial layer material include: RF power 120 W, oxygen partial pressure 2 Pa, and temperature 750°C.

[0052] In a preferred embodiment, in step (2), the exposure glue includes but is not limited to positive glue or negative glue; illustratively, in a specific embodiment of the present invention, the exposure glue is PMMA glue.

[0053] In a preferred embodiment, in step (2), the rotation speed of the spin-coated exposure glue is ≥3000rpm / s, and the spin-coating time is 50-60s; after the spin-coating is completed, a baking step is also included; the baking is specifically: baking on a hot plate at 100-150°C for 1-2 minutes.

[0054] In a preferred embodiment, in step (2), the exposure method includes but is not limited to ultraviolet lithography or electron beam exposure.

[0055] In a preferred embodiment, in step (2), the development time is 30 to 40 seconds; after the development is completed, a fixing step is also included; the fixing agent used is isopropyl alcohol.

[0056] In a preferred embodiment, in step (3), the deposition temperature of the deposited thin film material is 25-400° C. The present invention deposits the thin film material at a relatively low temperature, which can, on the one hand, avoid the photoresist from falling off due to high temperature during the deposition process, and on the other hand, reduce the slight deformation caused by the melting of the patterned photoresist during the deposition process, which is beneficial to improving the shape retention of the design pattern.

[0057] In a preferred embodiment, in step (3), the thin film material includes but is not limited to a crystalline material or an amorphous material; further preferably, the thin film material includes Au, Ag, Cu, Al, Cr, Ni, Pt, Pd, Te, HfO 2 、Al 2 O 3 , Sb 2 O 3 、TeO 2 、MoS 2 , WS 2 ,WSe 2 、MoTe 2 、SrTiO 3 One of the above; the deposition thickness of the deposited thin film material is 5 to 100 nm, and the surface roughness of the thin film layer obtained by the deposition of the thin film material is Ra≤0.8 nm.

[0058] In a preferred embodiment, in step (3), the deposition method of the deposited thin film material includes but is not limited to magnetron sputtering, thermal evaporation, electron beam evaporation, atomic layer deposition, pulsed laser deposition, molecular beam epitaxy, sol-gel method, chemical vapor deposition, plasma enhanced chemical vapor deposition, metal organic chemical vapor deposition, and is further preferably one of atomic layer deposition, magnetron sputtering, thermal evaporation, electron beam evaporation, and pulsed laser deposition.

[0059] In a preferred embodiment, in step (3), the degumming comprises the following steps: soaking in hot acetone at 80-120° C. for 10-30 min, then washing with isopropanol, and drying with nitrogen.

[0060] In a preferred embodiment, in step (4), the material of the organic support layer includes but is not limited to one or more of PMMA, PPC, and PVA; the number of layers of the spin coating is 1 to 4 layers, the baking temperature after spin coating is 80 to 150° C., and the single baking time is 1 to 3 minutes.

[0061] In a preferred embodiment, in step (4), the etching aqueous solution includes but is not limited to one or more of deionized water, an acidic aqueous solution, an alkaline aqueous solution, and a neutral aqueous solution; the acidic aqueous solution includes but is not limited to a dilute HCl aqueous solution, a dilute HNO 3 One or two of aqueous solutions; the alkaline aqueous solution includes but is not limited to NaOH aqueous solution, NH 4 OH aqueous solution; the neutral aqueous solution includes but is not limited to NaCl aqueous solution, Na 2 SO 4 One or two of the aqueous solutions; the etching time is ≤60 min, more preferably 5 to 60 min; the etching method is immersion.

[0062] In a preferred embodiment, the specific operation of step (5) is as follows:

[0063] S1. Using PDMS, the organic support layer carrying the patterned thin film material floating in the etching aqueous solution is fished out, and one side of the patterned thin film material is exposed to the air;

[0064] S2, using a precise transfer platform to position the organic support layer carrying the patterned thin film material in step S1 directly above the target device area;

[0065] S3, the PDMS is lowered until the organic support layer carrying the patterned thin film material contacts the target substrate, and the PDMS is lifted after heating at 50-130°C for 2-3 minutes to complete the transfer.

[0066] In a preferred embodiment, in step S3, after the PDMS is lifted after heating at 50-130°C for 2-3 minutes, a secondary degumming step is also included, and the secondary degumming includes the following steps: soaking in hot acetone at 80-120°C for 10-30 minutes, then washing with isopropanol, and blowing dry with nitrogen.

[0067] The room temperature in the embodiments of the present invention refers to "25±2°C".

[0068] Unless otherwise specified, the raw materials in the examples of the present invention were purchased from commercial sources.

[0069] Example 1

[0070] A method for transferring patterned thin film materials based on a soluble sacrificial layer, the process flow is shown in Figure 1 , the specific steps are as follows:

[0071] (1) A silicon wafer with a 300 nm thick oxide layer on the surface was cut into pieces of 5 mm*5 mm in size and ultrasonically cleaned with deionized water, acetone, and isopropanol for 5 min each to obtain a clean target substrate.

[0072] (2) Deposition of SrO and Al on the target substrate using magnetron sputtering 2 O 3 The molar ratio of SAO (strontium aluminate) is 3:1, and the deposition conditions are: RF power 120W, oxygen partial pressure 2Pa, temperature 750°C, and the deposition thickness is controlled at 30nm to form a SAO layer.

[0073] (3) Two layers of PMMA were spin-coated on the surface of the SAO layer. The spin coating speed of each layer of PMMA was 3000 rpm / s, and the spin coating time was 60 s. After each spin coating, it was heated and baked on a hot plate at 100°C for 1 min, and then patterned exposure was performed using an electron beam. The exposed sample was placed in a developer for 30 s and then fixed with isopropyl alcohol to form a patterned exposure adhesive layer.

[0074] (4) Atomic layer deposition was used to deposit hafnium oxide on the surface of the patterned exposure layer. The deposition temperature was 90°C, and the deposition was repeated for 180 cycles. The deposition thickness of hafnium oxide was 25 nm. After the deposition was completed, the sample was immersed in 100°C hot acetone for 30 minutes to remove excess hafnium oxide outside the pattern, thereby obtaining a patterned thin film material.

[0075] (5) A layer of PMMA and a layer of PPC are sequentially spin-coated on the surface of the patterned thin film material. The baking temperature after each spin coating is 80°C, and the single baking time is 1 min to form an organic support layer. The sample is then immersed in deionized water for 5 min to etch the SAO layer. After etching, the organic support layer carrying the patterned thin film material (i.e., the patterned hafnium oxide thin film material) floats on the water surface. It is fished out with PDMS, and one side of the patterned thin film material is exposed to the air. It is transferred to the target area of ​​the transistor device using a precise transfer platform. The PDMS is lowered until the patterned hafnium oxide thin film material contacts the target substrate. After heating at 130°C for 2 min, the PDMS is lifted up, and then secondary degumming is performed at 90°C with acetone. After soaking for 20 min, the degumming is completed. After cleaning with isopropanol and drying with nitrogen, a van der Waals contact top gate dielectric layer is obtained, and the transfer of the patterned thin film material array is realized.

[0076] Figure 2 The AFM surface morphology image (a) and thickness characterization image (b) of the SAO layer in step (2) of Example 1. Figure 2 It can be seen that the surface roughness of the SAO layer deposited in step (2) of Example 1 is good, with Ra being only about 0.3 nm, which is conducive to the deposition of the dielectric layer material covering the surface thereof.

[0077] Half of the substrate on which the SAO layer was deposited in step (2) of Example 1 was placed in deionized water, and the other half was exposed to air. After etching for 1 min, the material was placed under a light microscope for observation. Figure 3 .

[0078] Figure 3 The optical microscope images of the SAO layer deposited in step (2) of Example 1 after being obliquely placed in water for partial etching, wherein Figure a is magnified 50 times, Figure b is magnified 100 times, and Figure c is magnified 200 times. In Figures ac, the left side is the part exposed to the air, and the right side is the part after being placed in water for etching. Figure 3It can be seen that the prepared SAO layer can be successfully dissolved by water. After the SAO on the right side of the figure is dissolved, the color of the substrate silicon wafer is exposed.

[0079] Figure 4 This is an optical microscopic image of the patterned hafnium oxide thin film material fished out of PDMS in step (5) of Example 1.

[0080] Figure 5 The actual image (a) after the patterned hafnium oxide thin film material is transferred to the target area of ​​the transistor device in step (5) of Example 1 and the electrical performance of the transistor device before and after the patterned hafnium oxide thin film material is transferred (b). Figure 5 It can be seen from (b) that the electrical performance of the transistor device is almost unchanged before and after the transfer of the patterned hafnium oxide thin film material, which proves that the transfer method provided by the present invention is non-destructive to the transistor device.

[0081] A top gate gold electrode is deposited on the surface of the van der Waals contact top gate dielectric layer obtained in step (5) of Example 1 to construct a dual-gate transistor device. The schematic diagram of the structure of the dual-gate transistor device is shown in FIG. Figure 6 In (a), the optical microscope image of the dual-gate transistor device is shown in Figure 6 In (b), the electrical transfer curve of the dual-gate transistor device is shown in Figure 6 Middle (c).

[0082] Figure 6 The schematic diagram (a), optical microscope diagram (b) and electrical transfer curve diagram (c) of the double-gate transistor device constructed using the van der Waals contact top gate dielectric layer obtained in step (5) of Example 1, wherein in Figure a, S represents the source electrode, G represents the gate electrode, D represents the drain electrode, HfO 2 Represents patterned hafnium oxide thin film materials, Si, STO and MoS 2 The substrate that forms the target area. Figure 6 In (c), we can see that the fixed top gate voltage is -4V to 4V, the drain bias voltage is 1V, and the transfer curve of the test drain current Ids with the change of the bottom gate voltage shows that as the top gate voltage changes from negative to positive, the threshold voltage of the transistor gradually shifts to the negative direction, which is consistent with the theoretical inference. As the top gate voltage becomes more and more positive, the top gate will accumulate more and more electrons in the channel region in advance, so that the back gate can turn on the transistor under more and more negative back gate voltage. At the same time, the switching ratio of the transistor is 10 8 As the top gate voltage increases in the positive direction, the saturation current gradually increases. The above all prove that the patterned hafnium oxide thin film material obtained by the method provided by the present invention has excellent dielectric properties and can be applied to the construction of different types of electronic devices such as top gate transistors and dual gate transistors.

[0083] Example 2

[0084] A method for transferring patterned thin film materials based on a soluble sacrificial layer, the process flow is shown in Figure 1 , the specific steps are as follows:

[0085] (1) The titanium oxide-terminated STO (strontium titanate substrate) was cut into 5 mm*5 mm sizes and ultrasonically cleaned with deionized water, acetone, and isopropanol for 5 min each to obtain a clean target substrate.

[0086] (2) SAO was deposited on the target substrate by magnetron sputtering. The deposition conditions were: RF power 120 W, oxygen partial pressure 2 Pa, temperature 750° C., and the deposition thickness was controlled at 30 nm to form a SAO layer.

[0087] (3) Two layers of PMMA were spin-coated on the surface of the SAO layer. The spin coating speed of each layer of PMMA was 3000 rpm / s, and the spin coating time was 60 s. After each spin coating, it was heated and baked on a hot plate at 150°C for 1 min, and then patterned exposure was performed using an electron beam. The exposed sample was placed in a developer for 30 s and then fixed with isopropyl alcohol to form a patterned exposure adhesive layer.

[0088] (4) A 30 nm thick amorphous STO dielectric layer was deposited on the surface of the patterned exposure glue layer by magnetron sputtering. The magnetron sputtering parameters were: sputtering power 120 W, chamber temperature at room temperature, and oxygen partial pressure 2 Pa. After the deposition, the sample was immersed in 100 °C hot acetone for 30 min to remove the excess STO dielectric layer outside the pattern, thereby obtaining a patterned thin film material.

[0089] (5) A layer of PMMA and a layer of PPC were sequentially spin-coated on the surface of the patterned thin film material. The baking temperature after each spin coating was 80°C, and the single baking time was 1 min to form an organic support layer. The sample was then immersed in deionized water for 5 min to etch the SAO layer. After etching, the organic support layer carrying the patterned thin film material floated on the water surface. It was fished out with PDMS, and one side of the patterned thin film material was exposed to the air. It was transferred to the target area of ​​the transistor device using a precise transfer platform. The PDMS was lowered until the patterned thin film material was in contact with the target substrate. After heating at 130°C for 2 min, the PDMS was lifted up, and then secondary degumming was performed at 90°C with acetone. After soaking for 25 min, the degumming was completed. The sample was cleaned with isopropanol and dried with nitrogen to obtain a van der Waals contact top gate dielectric layer, thus realizing the transfer of large-scale patterned thin film materials.

[0090] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for transferring a patterned thin film material based on a soluble sacrificial layer, characterized in that: The following steps are involved: (1) After cleaning the substrate, a soluble sacrificial layer material is deposited on the substrate to form a soluble sacrificial layer; (2) spin coating an exposure glue on the surface of the soluble sacrificial layer described in step (1), and then patterning the exposure glue on the surface of the soluble sacrificial layer by exposure and development to form a patterned exposure glue layer; (3) depositing a thin film material on the surface of the patterned exposed adhesive layer described in step (2), and then performing a debonding process to obtain a patterned thin film material; (4) spin coating an organic support layer on the surface of the patterned thin film material obtained in step (3), and then placing the organic support layer in an etching aqueous solution to etch the soluble sacrificial layer to obtain an organic support layer carrying the patterned thin film material; (5) The organic support layer carrying the patterned thin film material obtained in step (4) is accurately transferred to the target position to achieve large-scale transfer of the patterned thin film material.

2. The method for transferring a patterned thin film material based on a soluble sacrificial layer according to claim 1, characterized in that: In step (1), the cleaning process is to use deionized water, acetone and isopropanol for ultrasonic cleaning for 3 to 5 minutes each.

3. The method for transferring a patterned thin film material based on a soluble sacrificial layer according to claim 1, characterized in that: In step (1), the substrate is selected from one of an insulating silicon substrate, a strontium titanate substrate, a sapphire substrate, a pure silicon substrate, a silicon oxide substrate, a gallium arsenide substrate, a silicon carbide substrate, a gallium nitride substrate, a magnesium oxide substrate, a glass substrate, a polycrystalline silicon substrate, an amorphous oxide substrate, a PET flexible substrate and a PI flexible substrate.

4. The method for transferring a patterned thin film material based on a soluble sacrificial layer according to claim 1, characterized in that: In step (1), the soluble sacrificial layer material is selected from one or more of strontium aluminate, glucose, carboxymethyl cellulose, polyethylene glycol, polyvinyl alcohol, gelatin, alginate, and chitosan.

5. The method for transferring a patterned thin film material based on a soluble sacrificial layer according to claim 1, characterized in that: In step (1), the thickness of the soluble sacrificial layer is 1-100 nm, and the surface roughness Ra of the soluble sacrificial layer is ≤0.8 nm.

6. The method for transferring a patterned thin film material based on a soluble sacrificial layer according to claim 1, characterized in that: In step (3), the deposition temperature of the deposited thin film material is 25 to 400° C.; the thin film material is selected from crystalline material or amorphous material; the deposition thickness of the deposited thin film material is 5 to 100 nm, and the surface roughness Ra of the thin film layer obtained by depositing the thin film material is ≤0.8 nm.

7. The method for transferring a patterned thin film material based on a soluble sacrificial layer according to claim 1, characterized in that: In step (4), the material of the organic support layer is selected from one or more of PMMA, PPC, and PVA; the number of layers of the spin coating is 1 to 4 layers, the baking temperature after spin coating is 80 to 150° C., and the single baking time is 1 to 3 minutes.

8. The method for transferring a patterned thin film material based on a soluble sacrificial layer according to claim 1, characterized in that: In step (4), the etching aqueous solution is selected from one or more of deionized water, acidic aqueous solution, alkaline aqueous solution, and neutral aqueous solution; and the etching time is ≤60 min.

9. The method for transferring a patterned thin film material based on a soluble sacrificial layer according to claim 1, characterized in that: The specific operation of step (5) is as follows: S1. Using PDMS, the organic support layer carrying the patterned thin film material floating in the etching aqueous solution is fished out, and one side of the patterned thin film material is exposed to the air; S2, using a precise transfer platform to position the organic support layer carrying the patterned thin film material in step S1 directly above the target device area; S3, the PDMS is lowered until the organic support layer carrying the patterned thin film material contacts the target substrate, and the PDMS is lifted after heating at 50-130°C for 2-3 minutes to complete the transfer.

10. The method for transferring a patterned thin film material based on a soluble sacrificial layer according to claim 1, characterized in that: The deposition method of the soluble sacrificial layer material in step (1) or the thin film material in step (3) is selected from magnetron sputtering, thermal evaporation, electron beam evaporation, atomic layer deposition, pulsed laser deposition, molecular beam epitaxy, sol-gel method, chemical vapor deposition, plasma enhanced chemical vapor deposition, and metal organic chemical vapor deposition.

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