Method for transferring wafer-size two-dimensional semiconductor film by selenium-assisted dry method

Abstract

The invention relates to a method for transferring a wafer-size two-dimensional semiconductor film through a selenium-assisted dry method, and belongs to the technical field of semiconductors. The method comprises the following steps: sequentially preparing a Se nano layer, a supporting layer and a water-soluble glue layer on a two-dimensional semiconductor film wafer containing a growth substrate; stripping the two-dimensional semiconductor film, the Se nano layer and the supporting layer from the growth substrate together by using a water-soluble glue layer, and then adhering the two-dimensional semiconductor film to a target substrate by taking the two-dimensional semiconductor film as an adhering surface; soaking in water to remove the water-soluble adhesive layer; and removing the support layer through reactive ion etching, and finally performing annealing treatment in an inert gas atmosphere to remove the Se nano layer, thereby obtaining the two-dimensional semiconductor film on the target substrate, and completing the transfer of the two-dimensional semiconductor film from the growth substrate to the target substrate. According to the invention, the wrinkle-free, residue-free and pollution-free high-quality complete cleaning transfer of the wafer-size two-dimensional semiconductor film can be effectively realized.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, and in particular to a method for transferring a wafer-sized two-dimensional semiconductor film by a selenium-assisted dry method. Background Art

[0002] In the post-Moore's Law era, two-dimensional semiconductors provide an important channel material system for the development of a new generation of integrated electronic technology due to their unique atomic layer thickness, suitable energy band gap, excellent mechanical flexibility, and controllable and adjustable carrier concentration. At present, researchers have achieved large-area epitaxial preparation of wafer-sized two-dimensional semiconductor films represented by molybdenum disulfide (MoS2) through methods such as chemical vapor deposition. However, due to the limitations of lattice matching conditions and thermodynamic factors, current high-quality two-dimensional semiconductor films are mainly epitaxially grown on special substrates such as sapphire. Therefore, transferring the two-dimensional semiconductor film from the original growth substrate to the target substrate with a dielectric oxide layer is one of the key steps that cannot be skipped in the device manufacturing process.

[0003] So far, the two-dimensional semiconductor film transfer strategy widely used in scientific research is mainly based on the wet transfer technology assisted by polymethyl methacrylate (PMMA). However, this wet transfer technology relying on organic polymers requires that the material be first immersed in an alkaline etchant (such as potassium hydroxide, etc.) to separate it from the original substrate, and then the polymer support layer on the surface of the material is removed through a sol-gel process using an organic solvent (such as acetone). This makes the transferred film prone to cracks, wrinkles, breakage, organic residues, and chemical corrosion, resulting in incomplete two-dimensional semiconductor films and reduced electrical quality, which cannot meet industrial requirements.

[0004] In order to develop batch thin film transfer technology suitable for two-dimensional semiconductor integrated circuit applications, researchers have developed a series of two-dimensional semiconductor thin film dry transfer technologies in recent years using polymers including polydimethylsiloxane (PDMS), polycarbonate (PPC), thermal release tape (TRT) or metals including gold (Au), silver (Ag) and bismuth (Bi) as adhesion transfer media. Because they can form strong van der Waals interactions with two-dimensional semiconductor films, this type of dry transfer technology has shown great application potential in maintaining the integrity of large areas of two-dimensional semiconductor films. However, dry transfer technology using polymers or metals as transfer media also requires additional steps (such as organic solvent sol, acidic liquid etching, electrochemical separation, etc.) to remove the corresponding supporting layer from the surface of the two-dimensional semiconductor film after the transfer is completed, which will inevitably cause residual contamination on the film surface and damage to the integrity, making it difficult for the transferred two-dimensional semiconductor electrical properties to reach the expected goals.

[0005] Therefore, in order to promote the rapid integration of two-dimensional semiconductors and the new generation of micro-nano semiconductor industry technologies, the field urgently needs to develop a simple and reliable strategy to achieve complete transfer of two-dimensional semiconductor films without wrinkles, residues, and clean surfaces. Summary of the invention

[0006] Based on the above-mentioned bottlenecks in two-dimensional semiconductor thin film transfer technology, the present invention provides a method for selenium-assisted dry transfer of two-dimensional semiconductor thin films, aiming to solve the problem that the existing dry transfer technology using polymers or metals as transfer media still causes residual contamination on the surface of the two-dimensional semiconductor film and damages its integrity.

[0007] The technical solution of the present invention is as follows:

[0008] A method for selenium-assisted dry transfer of wafer-sized two-dimensional semiconductor thin films, comprising the following steps:

[0009] Providing a wafer-sized two-dimensional semiconductor film containing a growth substrate, denoted as two-dimensional semiconductor film / growth substrate;

[0010] Sequentially preparing a Se nanolayer, a supporting layer and a water-soluble adhesive layer on the two-dimensional semiconductor film of the two-dimensional semiconductor film / growth substrate to obtain a water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film / growth substrate;

[0011] Using a water-soluble adhesive layer to peel off the water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film from the growth substrate to obtain a water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film;

[0012] Laminating the water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film onto a target substrate with the two-dimensional semiconductor film as a laminating surface to obtain a water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film / target substrate;

[0013] Soaking the water-soluble glue layer / support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate in water to remove the water-soluble glue layer, thereby obtaining the support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate;

[0014] Removing the support layer in the support layer / Se nanolayer / two-dimensional semiconductor film / target substrate by reactive ion etching to obtain the Se nanolayer / two-dimensional semiconductor film / target substrate;

[0015] The Se nanolayer / two-dimensional semiconductor film / target substrate is annealed in an inert gas atmosphere to completely evaporate the Se nanolayer to obtain a two-dimensional semiconductor film / target substrate, thereby completing the transfer of the two-dimensional semiconductor film from the growth substrate to the target substrate.

[0016] Optionally, the two-dimensional semiconductor film is a MoS2 film, a MoSe2 film, a WS2 film or a WSe2 film, but is not limited thereto.

[0017] Optionally, the wafer size of the two-dimensional semiconductor film is 2-12 inches.

[0018] Optionally, the Se nanolayer is prepared by physical vapor deposition, electron beam thermal evaporation or resistance thermal evaporation.

[0019] Optionally, the Se nanolayer has a thickness of 80-150 nm.

[0020] Optionally, the support layer is made of polypropylene carbonate.

[0021] Optionally, the support layer is prepared by a coating method.

[0022] Optionally, the growth substrate is a sapphire substrate, a quartz substrate, a mica substrate, or the like.

[0023] Optionally, the target substrate is a substrate with a dielectric oxide layer (such as Al2O3, HfO2, etc.).

[0024] Optionally, the annealing treatment is performed for 5-8 hours at a temperature of 250-300°C.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) A new method for dry transfer of two-dimensional semiconductor thin films from a growth substrate to a target substrate using Se nanolayers is provided, which has the advantages of simple operation and lossless transfer.

[0027] (2) The two-dimensional semiconductor thin film transfer method proposed in the present invention can achieve large-area, efficient and complete transfer of wafer-sized two-dimensional semiconductor thin films without wrinkles, pollution or residue.

[0028] (3) The method provided by the present invention has the advantage of being compatible with standard semiconductor process flow, and can provide a potential solution to the problem of large-area thin film transfer in the future large-scale manufacturing of high-performance two-dimensional semiconductor integrated electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the preparation method of Example 1.

[0030] Figure 2 This is a physical picture of Example 1 in which PPC / Se / MoS2 is peeled off from a sapphire substrate using a water-soluble tape. The left picture is a physical picture of PPC / Se / MoS2 adhered to the water-soluble tape, and the right picture is a physical picture of the sapphire substrate after peeling.

[0031] Figure 3 This is a real picture of PPC / Se / MoS2 after being bonded to the target substrate in Example 1.

[0032] Figure 4 This is a physical picture of a single-layer MoS2 film in the MoS2 / target substrate of Example 1.

[0033] Figure 5 This is an optical microscope image of a single-layer MoS2 film in the MoS2 / target substrate of Example 1.

[0034] Figure 6 This is an atomic force microscope image of a single-layer MoS2 film in the MoS2 / target substrate of Example 1.

[0035] Figure 7 This is a comparison chart of the Raman spectra of the MoS2 / sapphire substrate, Se / MoS2 / sapphire substrate and MoS2 / target substrate of Example 1.

[0036] Figure 8 This is a high-resolution transmission electron microscopy image of a single-layer MoS2 film in the MoS2 / target substrate of Example 1.

[0037] Fig. 9 This is the selected electron area diffraction pattern of the single-layer MoS2 film in the MoS2 / target substrate of Example 1.

[0038] Fig.10 This is a schematic diagram of the FET device structure prepared using the MoS2 / target substrate obtained by the method of Example 1, wherein the channel size of MoS2 as a carrier transmission channel is 3 μm in length and 15 μm in width.

[0039] Fig.11 This is a diagram of the electrical performance of a FET device prepared using the MoS2 / target substrate obtained by the method of Example 1.

[0040] Fig.12 This is a physical picture of the single-layer MoS2 film in PMMA / MoS2 before removing the PMMA glue in Comparative Example 1.

[0041] Fig.13 This is a physical picture of the single-layer MoS2 film in the MoS2 / target substrate after removing the PMMA glue in Comparative Example 1.

[0042] Fig.14 Optical microscope image of a single-layer MoS2 film in the PMMA-assisted wet-transferred MoS2 / target substrate of Comparative Example 1.

[0043] Fig.15AFM image of a single-layer MoS2 film in the PMMA-assisted wet-transferred MoS2 / target substrate of Comparative Example 1.

[0044] Fig.16 This is the electrical performance diagram of the FET device prepared by using PMMA-assisted wet transfer of MoS2 thin film in Comparative Example 1. DETAILED DESCRIPTION

[0045] The present invention provides a method for transferring wafer-sized two-dimensional semiconductor thin films by selenium-assisted dry method. In order to make the purpose, technical scheme and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0046] The embodiment of the present invention provides a method for selenium-assisted dry transfer of a wafer-sized two-dimensional semiconductor film, which includes the following steps:

[0047] Providing a wafer-sized two-dimensional semiconductor film containing a growth substrate, denoted as two-dimensional semiconductor film / growth substrate;

[0048] Sequentially preparing a Se nanolayer, a supporting layer and a water-soluble adhesive layer on the two-dimensional semiconductor film of the two-dimensional semiconductor film / growth substrate to obtain a water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film / growth substrate;

[0049] Using a water-soluble adhesive layer to peel off the water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film from the growth substrate to obtain a water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film;

[0050] Laminating the water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film onto a target substrate with the two-dimensional semiconductor film as a laminating surface to obtain a water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film / target substrate;

[0051] Soaking the water-soluble glue layer / support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate in water to remove the water-soluble glue layer, thereby obtaining the support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate;

[0052] Removing the support layer in the support layer / Se nanolayer / two-dimensional semiconductor film / target substrate by reactive ion etching to obtain the Se nanolayer / two-dimensional semiconductor film / target substrate;

[0053] The Se nanolayer / two-dimensional semiconductor film / target substrate is annealed in an inert gas atmosphere to completely evaporate the Se nanolayer to obtain a two-dimensional semiconductor film / target substrate, thereby completing the transfer of the two-dimensional semiconductor film from the growth substrate to the target substrate.

[0054] An embodiment of the present invention provides a method for selenium-assisted dry transfer of a wafer-sized two-dimensional semiconductor film (also referred to as a two-dimensional semiconductor film wafer), wherein a Se nanolayer is first deposited on the two-dimensional semiconductor film / a two-dimensional semiconductor film of a growth substrate, and then a support layer is deposited on the Se nanolayer to prevent damage to the Se nanolayer, and then a water-soluble adhesive layer is tightly attached to the support layer, and with the assistance of the water-soluble adhesive layer, the water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film is peeled off from the growth substrate (it can be machine-peeled or manually-peeled off) and tightly attached to a target substrate; then, after being immersed in water to remove the water-soluble adhesive layer on the surface, reactive ion etching is used to remove trace residual adhesive and the support layer on the surface, and then, annealing is performed in an inert atmosphere to remove the Se nanolayer, thereby obtaining a two-dimensional semiconductor film / target substrate, and completing the dry transfer process of transferring the two-dimensional semiconductor film from the growth substrate to the target substrate. The embodiment of the present invention adopts a selenium (a semi-metal)-assisted method to transfer a wafer-sized two-dimensional semiconductor film from a growth substrate to a target substrate, thereby achieving a high-quality, complete and clean transfer of the wafer-sized two-dimensional semiconductor film without wrinkles, residues or pollution.

[0055] In one implementation, the growth substrate may be a sapphire substrate, or may be other required growth substrates, such as a quartz substrate, a mica substrate, and the like.

[0056] In one embodiment, the growth substrate may be a growth substrate of any wafer size, and the wafer size of the growth substrate may be 2-12 inches, such as 2 inches, 4 inches, 6 inches, 8 inches, 10 inches, 12 inches, etc., but is not limited to the above sizes, and may also be a small piece area size after cutting, such as 1×1 cm 2 , and can be adjusted according to actual needs. The wafer size in this article refers to the wafer diameter.

[0057] In one embodiment, the two-dimensional semiconductor film can be a MoS2 film, a MoSe2 film, a WS2 film, a WSe2 film, etc., but is not limited thereto. The method for transferring a wafer-sized two-dimensional semiconductor film by selenium-assisted dry method provided in the embodiment of the present invention is also applicable to the transfer of other two-dimensional material films, such as a graphene film or a boron nitride film. Among them, the two-dimensional semiconductor film can be a single layer or a multi-layer, preferably a single-layer two-dimensional semiconductor film, and more preferably a single-layer MoS2 film.

[0058] In one embodiment, the wafer size of the two-dimensional semiconductor film can be 2-12 inches, such as 2 inches, 4 inches, 6 inches, 8 inches, 10 inches, 12 inches, etc., but is not limited to the above sizes. It can also be a small piece area size after cutting, such as 1×1 cm 2, specifically adjusted according to actual needs. Preferably, the wafer size of the two-dimensional semiconductor film is consistent with the wafer size of the growth substrate.

[0059] In one embodiment, the Se nanolayer is prepared by physical vapor deposition, electron beam thermal evaporation or resistance thermal evaporation.

[0060] In one embodiment, the thickness of the Se nanolayer is 80-150 nm, such as 80 nm, 100 nm, 120 nm, 150 nm, etc.

[0061] In one embodiment, the support layer may be a polypropylene carbonate layer (PPC layer) or the like, but is not limited thereto, and the method for preparing the support layer may be a coating method, such as spin coating, etc. The support layer in the embodiment of the present invention is relatively thin and has a certain mechanical strength, and its function is to prevent the Se nanolayer from being damaged.

[0062] In one embodiment, the thickness of the support layer may be 100 nm-1 μm, such as 200 nm, 300 nm, 500 nm, etc.

[0063] In one embodiment, the water-soluble adhesive layer is a water-soluble adhesive tape or a water-soluble adhesive layer made of hydrosol, wherein the water-soluble adhesive tape can also be replaced by a thermal release adhesive tape. The water-soluble adhesive layer is mainly used as a peeling medium and can provide stronger adhesion.

[0064] It should be noted that when the water-soluble adhesive layer is a water-soluble tape, it is only necessary to adhere the water-soluble tape to the support layer; when the water-soluble adhesive layer is a hydrosol, it is necessary to brush or spin-coat the hydrosol onto the support layer and then wait for it to solidify. During the bonding, the water-soluble adhesive layer faces outward, and the two-dimensional semiconductor film is closely bonded to the target substrate as the bonding surface.

[0065] In one embodiment, the target substrate is a substrate (such as a SiO2 / Si substrate, a mica substrate or a quartz substrate) with a dielectric oxide layer (such as a SiO2 layer, an Al2O3 layer, a HfO2 layer, etc.). The thickness of the dielectric oxide layer can be 3-50nm, such as 5nm, 20nm, etc. The target substrate is preferably a SiO2 / Si substrate with an Al2O3 dielectric oxide layer.

[0066] In one embodiment, the annealing treatment is performed for 5-8 hours at a temperature of 250-300° C. The purpose of annealing is to remove the Se nanolayer on the surface, thereby obtaining a large-area, complete and clean two-dimensional semiconductor film.

[0067] The present invention will be further described below by means of specific examples.

[0068] Example 1

[0069] This embodiment adopts a method of transferring wafer-sized two-dimensional semiconductor thin films by selenium-assisted dry method, combined with Figure 1 As shown, the specific steps include:

[0070] (1) A pre-prepared wafer-sized MoS2 film containing a sapphire substrate (referred to as MoS2 / sapphire substrate) is provided, wherein the size of the sapphire substrate is 2 inches, the size of the MoS2 film is 2 inches, and a Se nanolayer with a thickness of 100 nm is uniformly prepared on the MoS2 film on the sapphire substrate by physical vapor deposition. Specifically, Se particles are first used as an evaporation source, and the MoS2 / sapphire substrate (MoS2 film facing upward) is placed at a fixed distance of about 30 cm from the evaporation source, the heating temperature of the Se particles is set to 270°C, and the evaporation time lasts for about 40 minutes. The sample obtained in this step is recorded as Se / MoS2 / sapphire substrate.

[0071] (2) A 5 wt % polypropylene carbonate (PPC) solution was spin-coated at 6000 rpm for 60 s on the Se nanolayer of the Se / MoS2 / sapphire substrate in step (1), and then baked at 50°C to evaporate the solvent to obtain a PPC support layer on the Se nanolayer. The purpose of preparing the support layer is to prevent damage to the Se nanolayer. The sample obtained in this step is recorded as PPC / Se / MoS2 / sapphire substrate.

[0072] (3) The water-soluble tape was tightly attached to the PPC support layer of the PPC / Se / MoS2 / sapphire substrate.

[0073] (4) PPC / Se / MoS2 was peeled off from the sapphire substrate together by using a water-soluble tape, e.g. Figure 2 As shown, the left picture is a physical picture of PPC / Se / MoS2 adhered to the water-soluble tape, and the right picture is a physical picture of the sapphire substrate after peeling; then the obtained PPC / Se / MoS2 adhered to the water-soluble tape is tightly adhered to the target substrate; wherein, the target substrate is a 3-inch SiO2 / Si substrate with an Al2O3 dielectric oxide layer (thickness is 20nm).

[0074] (5) The sample prepared in step (4) was placed in a petri dish filled with deionized water and soaked for about 5 min until the water-soluble tape was naturally separated from the PPC / Se / MoS2 surface. Figure 3 As shown, from Figure 3 It can be seen that PPC / Se / MoS2 was completely transferred to the target substrate; the sample was fished out from deionized water after removing the water-soluble tape and then dried naturally.

[0075] (6) Then, the PPC support layer on the sample surface was removed by reactive ion etching, and then annealing was performed in an argon atmosphere (temperature of 280°C, time of 5 h) to completely evaporate the Se nanolayer on the surface of the MoS2 film to obtain MoS2 / target substrate; the results are shown in FIG. Figure 4 As shown, from Figure 4 It can be seen that a large area of ​​clean and undamaged single-layer MoS2 film was obtained in this embodiment.

[0076] The samples obtained in the above examples were subjected to relevant material characterization, device preparation and testing.

[0077] The optical microscope photo of the single-layer MoS2 film obtained in step (6) is as follows: Figure 5 As shown, from Figure 5 It can be seen that the surface of the transferred MoS2 film is clean without wrinkles, damage, or residue.

[0078] The atomic force microscope (AFM) image of the single-layer MoS2 film obtained in step (6) is as follows: Figure 6 As shown, from Figure 6 It can be seen that the surface roughness (RMS) of the transferred MoS2 film is about 0.19nm, retaining a high atomic-level flatness.

[0079] Figure 7 The Raman spectra of the MoS2 / sapphire substrate before step (1) in Example 1, the Se / MoS2 / sapphire substrate obtained after step (1), and the MoS2 / target substrate obtained after step (6) are compared. Figure 7 It can be seen that there is no characteristic peak of Se in the MoS2 film transferred by this method, indicating that there is no Se residue in the sample.

[0080] Figure 8 is a high-resolution transmission electron microscopic image of the single-layer MoS2 film after step (6) of Example 1, from Figure 8 It can be seen that no atomic defects are observed in the transferred MoS2 film.

[0081] Fig. 9 is the selected electron area diffraction pattern of the single-layer MoS2 film after step (6) of Example 1, from Fig. 9 It can be seen that the transferred MoS2 film still retains the single crystal characteristics.

[0082] In summary, the method of the present invention can effectively achieve high-quality, complete and clean transfer of wafer-sized two-dimensional semiconductor films without wrinkles, residues or pollution.

[0083] Fig.10 , 11The schematic diagram and electrical performance diagram of the FET device prepared by the MoS2 / target substrate obtained by the method of Example 1 are respectively shown. The FET device is mainly composed of MoS2 / target substrate, source (S), drain (D) and gate (Gate), and the gate can be Ti / Au / Ti. Fig.10 As shown in the figure, the length of the MoS2 carrier transport channel in the FET device is 3μm, the width is 15μm, and the contact metal is Au / Ti / Au. Fig.11 It can be seen that the MoS2 thin film transferred by this method has relatively high electrical properties.

[0084] Comparative Example 1

[0085] This comparative example adopts a method for wet transfer of wafer-sized two-dimensional semiconductor thin films based on polymer PMMA, which specifically includes the following steps:

[0086] (1) providing a pre-prepared wafer-sized MoS2 film containing a sapphire substrate (denoted as MoS2 / sapphire substrate), wherein the size of the sapphire substrate is 2 inches, and the size of the MoS2 film is 2 inches;

[0087] (2) First, a PMMA support layer is prepared on a MoS2 thin film on a sapphire growth substrate to obtain a PMMA / MoS2 / sapphire substrate.

[0088] (3) The PMMA / MoS2 / sapphire substrate is then immersed in a potassium hydroxide solution for etching and subsequently transferred to deionized water, so that the PMMA / MoS2 is detached from the sapphire substrate and floats on the liquid surface, thereby obtaining a PMMA / MoS2 thin film.

[0089] (4) PMMA / MoS2 was then transferred to a 3-inch SiO2 / Si substrate (i.e., the target substrate) with an Al2O3 dielectric oxide layer (thickness of 20 nm), and finally the PMMA support layer was removed by immersion in acetone to obtain the MoS2 / target substrate.

[0090] The specific results are as follows:

[0091] Fig.12 This is a physical picture of the single-layer MoS2 film in PMMA / MoS2 before removing the PMMA glue in comparative example 1.

[0092] Fig.13 This is a physical picture of the single-layer MoS2 film in the MoS2 / target substrate after removing the PMMA glue in Comparative Example 1.

[0093] Fig.14 Optical microscope image of a single-layer MoS2 film in the PMMA-assisted wet-transferred MoS2 / target substrate of Comparative Example 1.

[0094] Fig.15 AFM image of a single-layer MoS2 film in the PMMA-assisted wet-transferred MoS2 / target substrate of Comparative Example 1.

[0095] from Fig.12 , 13 It can be clearly seen that the single-layer MoS2 film in this comparative example using PMMA-assisted wet transfer has obvious wrinkles, damage and residual glue, which can be further seen from Fig.14 and Fig.15 This is further confirmed by Fig.14 It can be seen from the optical microscope photos that the MoS2 film after PMMA-assisted transfer has surface damage and organic residues, and its quality is obviously inferior to that of MoS2 transferred by Se-assisted dry method ( Figure 5 ).from Fig.15 It can be seen that the surface roughness (RMS) of the transferred MoS2 film is about 0.65 nm, and the flatness is relatively low.

[0096] Therefore, the wet transfer technology assisted by PMMA polymer will cause residual contamination on the surface of the two-dimensional semiconductor film, damage to the integrity, etc., so that the electrical performance of the FET device prepared by MoS2 / target substrate obtained by the method of Comparative Example 1 (the same as the FET device of Example 1) is ( Fig.16 )It is difficult to achieve the expected goals.

[0097] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for selenium-assisted dry transfer of wafer-sized two-dimensional semiconductor thin films, characterized in that: The steps include: Providing a wafer-sized two-dimensional semiconductor film containing a growth substrate, denoted as two-dimensional semiconductor film / growth substrate; Sequentially preparing a Se nanolayer, a supporting layer and a water-soluble adhesive layer on the two-dimensional semiconductor film of the two-dimensional semiconductor film / growth substrate to obtain a water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film / growth substrate; Using a water-soluble adhesive layer to peel off the water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film from the growth substrate to obtain a water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film; Laminating the water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film onto a target substrate with the two-dimensional semiconductor film as a laminating surface to obtain a water-soluble adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor film / target substrate; Soaking the water-soluble glue layer / support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate in water to remove the water-soluble glue layer, thereby obtaining the support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate; Removing the support layer in the support layer / Se nanolayer / two-dimensional semiconductor film / target substrate by reactive ion etching to obtain the Se nanolayer / two-dimensional semiconductor film / target substrate; The Se nanolayer / two-dimensional semiconductor film / target substrate is annealed in an inert gas atmosphere to completely evaporate the Se nanolayer to obtain a two-dimensional semiconductor film / target substrate, thereby completing the transfer of the two-dimensional semiconductor film from the growth substrate to the target substrate.

2. The method for selenium-assisted dry transfer of wafer-sized two-dimensional semiconductor thin films according to claim 1, characterized in that: The two-dimensional semiconductor film is a MoS2 film, a MoSe2 film, a WS2 film or a WSe2 film.

3. The method for selenium-assisted dry transfer of wafer-sized two-dimensional semiconductor thin films according to claim 1, characterized in that: The wafer size of the two-dimensional semiconductor film is 2-12 inches.

4. The method for selenium-assisted dry transfer of wafer-sized two-dimensional semiconductor thin films according to claim 1, characterized in that: The Se nanolayer is prepared by physical vapor deposition, electron beam thermal evaporation or resistance thermal evaporation.

5. The method for selenium-assisted dry transfer of wafer-sized two-dimensional semiconductor thin films according to claim 1 or 4, characterized in that: The thickness of the Se nanolayer is 80-150 nm.

6. The method for selenium-assisted dry transfer of wafer-sized two-dimensional semiconductor thin films according to claim 1, characterized in that: The support layer is made of polypropylene carbonate.

7. A method for selenium-assisted dry transfer of wafer-sized two-dimensional semiconductor thin films according to claim 1 or 6, characterized in that: The support layer is prepared by a coating method.

8. The method for selenium-assisted dry transfer of wafer-sized two-dimensional semiconductor thin films according to claim 1, characterized in that: The growth substrate is a sapphire substrate, a quartz substrate or a mica substrate.

9. The method for selenium-assisted dry transfer of wafer-sized two-dimensional semiconductor thin films according to claim 1, characterized in that: The target substrate is a substrate with a dielectric oxide layer.

10. The method for selenium-assisted dry transfer of wafer-sized two-dimensional semiconductor thin films according to claim 1, characterized in that: The annealing treatment is performed for 5-8 hours at a temperature of 250-300°C.

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