A method for selenium-assisted dry transfer of wafer-sized two-dimensional semiconductor films

Abstract

The present invention relates to a method for selenium-assisted dry transfer of wafer-sized two-dimensional semiconductor thin films, belonging to the field of semiconductor technology. The method comprises the following steps: sequentially preparing a Se nanolayer, a support layer, and a water-soluble adhesive layer on a two-dimensional semiconductor thin film wafer containing a growth substrate; utilizing the water-soluble adhesive layer to peel the two-dimensional semiconductor thin film, the Se nanolayer, and the support layer from the growth substrate, and then laminating the two-dimensional semiconductor thin film to a target substrate using the two-dimensional semiconductor thin film as a laminating surface; subsequently, soaking the film in water to remove the water-soluble adhesive layer; then, removing the support layer by reactive ion etching, and finally, annealing in an inert gas atmosphere to remove the Se nanolayer, thereby obtaining a two-dimensional semiconductor thin film on the target substrate and completing the transfer of the two-dimensional semiconductor thin film from the growth substrate to the target substrate. The present invention can effectively achieve high-quality, complete, and clean transfer of wafer-sized two-dimensional semiconductor thin films without wrinkles, residue, or pollution.

Description

Technical Field

[0001] The present 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 process. 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 technologies 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] To date, the most widely used 2D semiconductor thin film transfer strategy in scientific research is primarily based on a wet transfer technique assisted by polymethyl methacrylate (PMMA). However, this wet transfer technique, which relies on organic polymers, requires first immersing the material in an alkaline etchant (such as potassium hydroxide) to detach it from the original substrate. The polymer support layer on the surface of the material is then 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. This leads to incomplete 2D semiconductor films and reduced electrical quality, making them unable to meet industrial requirements.

[0004] To develop mass-produced thin-film transfer technologies suitable for two-dimensional semiconductor integrated circuit applications, researchers have recently developed a series of dry-process transfer techniques for two-dimensional semiconductor thin films using polymers, including polydimethylsiloxane (PDMS), polycarbonate (PPC), and thermal release tape (TRT), or metals, including gold (Au), silver (Ag), and bismuth (Bi), as adhesion transfer media. Because these materials can form strong van der Waals interactions with two-dimensional semiconductor films, these dry-process transfer techniques have shown great potential for maintaining the integrity of large-area two-dimensional semiconductor films. However, dry-process transfer techniques using polymers or metals as transfer media also require additional steps (such as organic solvent sols, acidic liquid etching, and electrochemical separation) to remove the corresponding supporting layer from the surface of the two-dimensional semiconductor film after the transfer is completed. This inevitably causes residual contamination on the film surface and damages its integrity, making it difficult to achieve the expected electrical properties of the transferred two-dimensional semiconductor.

[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 damage to its integrity.

[0007] The technical solutions of the present invention are 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 support 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 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 adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate in water to remove the water-soluble adhesive layer, thereby obtaining the support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate;

[0014] Removing the support layer from the support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate by reactive ion etching to obtain the Se nanolayer / two-dimensional semiconductor thin 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 time is 5-8 hours and the temperature is 250-300°C.

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

[0026] (1) A new dry transfer method for 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 flows, 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 where 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 in 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] Figure 9 This is the selected electron area diffraction pattern of the single-layer MoS2 film in the MoS2 / target substrate of Example 1.

[0038] Figure 10 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 the carrier transmission channel is 3μm in length and 15μm in width.

[0039] Figure 11 Graph showing the electrical performance of a FET device fabricated using the MoS2 / target substrate obtained using the method of Example 1.

[0040] Figure 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] Figure 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] Figure 14 Optical microscope image of a single-layer MoS2 film in the PMMA-assisted wet-transferred MoS2 / target substrate of Comparative Example 1.

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

[0044] Figure 16 This is a diagram of the electrical performance 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 dry-process transfer of wafer-sized two-dimensional semiconductor thin films assisted by selenium. To clarify the objectives, technical solutions, and effects of the present invention, the present invention is described in further detail below. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0046] An embodiment of the present invention provides a method for selenium-assisted dry transfer of a wafer-sized two-dimensional semiconductor thin film, comprising 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 support 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 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 adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate in water to remove the water-soluble adhesive layer, thereby obtaining the support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate;

[0052] Removing the support layer from the support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate by reactive ion etching to obtain the Se nanolayer / two-dimensional semiconductor thin 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 wafer-sized two-dimensional semiconductor films (also referred to as two-dimensional semiconductor film wafers), firstly, a Se nanolayer is deposited on the two-dimensional semiconductor film / growth substrate of the two-dimensional semiconductor film, 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 adhered 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 adhered to the target substrate; then, after soaking 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 treatment is performed in an inert atmosphere to remove the Se nanolayer, thereby obtaining a two-dimensional semiconductor film / target substrate, 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 embodiment, the growth substrate may be a sapphire substrate, or other required growth substrates, such as a quartz substrate, a mica substrate, etc.

[0056] In one embodiment, the growth substrate may be a growth substrate of any wafer size. 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. The wafer size may also be a small piece size after cutting, such as 1×1 cm 2 , and adjust according to actual needs. The wafer size in this article refers to the wafer diameter.

[0057] In one embodiment, the two-dimensional semiconductor film may be, but is not limited to, a MoS2 film, a MoSe2 film, a WS2 film, or a WSe2 film. The selenium-assisted dry transfer method for wafer-scale two-dimensional semiconductor films provided in the embodiments of the present invention is also applicable to the transfer of other two-dimensional material films, such as graphene films or boron nitride films. The two-dimensional semiconductor film may be a single layer or a multilayer, preferably a single layer, and more preferably a single layer of 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 2Preferably, the wafer size of the two-dimensional semiconductor thin 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), but is not limited thereto. The support layer may be prepared by a coating method, such as spin coating. 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 damage to the Se nanolayer.

[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 a hydrosol, wherein the water-soluble adhesive tape can also be replaced by a heat-release adhesive tape. The water-soluble adhesive layer mainly serves 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, the tape is simply bonded to the support layer. When the water-soluble adhesive layer is a hydrosol, the hydrosol is brushed or spin-coated onto the support layer and then allowed to cure. During bonding, the water-soluble adhesive layer faces outward, and the two-dimensional semiconductor film serves as the bonding surface, tightly bonding to the target substrate.

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

[0066] In one embodiment, the annealing treatment lasts 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 through 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 on a sapphire substrate (denoted as MoS2 / sapphire substrate) is provided, wherein the sapphire substrate is 2 inches in size and the MoS2 film is 2 inches in size. A Se nanolayer with a thickness of 100 nm is uniformly deposited on the MoS2 film on the sapphire substrate using physical vapor deposition. Specifically, Se particles are first used as an evaporation source. The MoS2 / sapphire substrate (with the MoS2 film facing upward) is placed at a fixed distance of approximately 30 cm from the evaporation source. The heating temperature of the Se particles is set to 270°C, and the evaporation time is continued for approximately 40 minutes. The sample obtained in this step is denoted 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 were peeled off from the sapphire substrate together by using water-soluble tape, as shown in 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 culture dish filled with deionized water and soaked for about 5 minutes 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 treatment 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 this embodiment obtains a large area of ​​clean and undamaged single-layer MoS2 film.

[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 0.19 nm, 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 The high-resolution transmission electron microscopy image of the single-layer MoS2 film after step (6) of Example 1 is shown in FIG. Figure 8 It can be seen that no atomic defects are observed in the transferred MoS2 film.

[0081] Figure 9 The selected electron area diffraction pattern of the single-layer MoS2 film after step (6) of Example 1 is shown in FIG. Figure 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] Figure 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 mainly consists of MoS2 / target substrate, source (S), drain (D) and gate (Gate), and the gate can be Ti / Au / Ti. Figure 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. Figure 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 assisted by 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 was prepared on the MoS2 thin film on the 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 onto 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] Figure 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] Figure 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] Figure 14 Optical microscope image of a single-layer MoS2 film in the PMMA-assisted wet-transferred MoS2 / target substrate of Comparative Example 1.

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

[0095] from Figure 12 、 13 It can be clearly seen that the single-layer MoS2 film transferred by PMMA-assisted wet method in this comparative example has obvious wrinkles, damage and residual glue, which can be further seen from the Figure 14 and Figure 15 This is further confirmed by Figure 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 significantly inferior to that of MoS2 transferred by Se-assisted dry method ( Figure 5 ).from Figure 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 PMMA polymer-assisted wet transfer technology will cause residual contamination on the surface of the two-dimensional semiconductor film, damage to its integrity, etc., which will cause the electrical performance of the FET device prepared by the MoS2 / target substrate obtained by the method of Comparative Example 1 (the same as the FET device of Example 1) to be reduced. Figure 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 those skilled in the art, 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 support 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 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 adhesive layer / support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate in water to remove the water-soluble adhesive layer, thereby obtaining the support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate; Removing the support layer from the support layer / Se nanolayer / two-dimensional semiconductor thin film / target substrate by reactive ion etching to obtain the Se nanolayer / two-dimensional semiconductor thin 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 of claim 1, wherein the selenium-assisted dry transfer method for wafer-sized two-dimensional semiconductor thin films is 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 of claim 1, wherein the selenium-assisted dry transfer method for wafer-sized two-dimensional semiconductor thin films is 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 of claim 1, wherein the selenium-assisted dry transfer method for wafer-sized two-dimensional semiconductor thin films is characterized in that: The supporting layer is made of polypropylene carbonate.

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

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

9. The method of claim 1, wherein the selenium-assisted dry transfer method for wafer-sized two-dimensional semiconductor thin films is 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 time is 5-8 hours and the temperature is 250-300°C.

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