Transfer method and heterogeneous integration method of two-dimensional bismuth oxide selenide film

Abstract

The invention provides a transfer method and a heterogeneous integration method of a two-dimensional bismuth selenide film, and relates to the technical field of semiconductor materials. According to the transfer method of the two-dimensional bismuth selenide thin film, lossless and clean transfer of the bismuth selenide thin film is achieved through a composite transfer medium of the TRT layer / the supporting layer / the stress layer / the oxide layer, the oxide layer serves as a contact layer in the transfer process, it can be guaranteed that bismuth selenide is prevented from being damaged in the transfer process, the excellent electrical property of the bismuth selenide is guaranteed, and the transfer efficiency of the two-dimensional bismuth selenide thin film is improved. The stress layer provides tensile stress, dry-method lossless stripping of wafer-level bismuth selenide can be achieved, the supporting layer can avoid cracking of the film in the stripping process, lossless and clean transfer of the bismuth selenide film is achieved, the transferred bismuth selenide film is complete and continuous, the surface is smooth, the surface roughness is smaller than 0.65 nm, and the film uniformity is good.

Description

Technical Field

[0001] This invention relates to the field of semiconductor materials technology, and in particular to a method for transferring two-dimensional bismuth selenide oxide thin films and a method for heterogeneous integration thereof. Background Technology

[0002] Two-dimensional bismuth selenide oxide (BSE) is a novel air-stable, high-mobility two-dimensional semiconductor material. It has a tetragonal crystal phase and consists of layered, positively charged [Bi₂O₂] atoms. n 2n+ And the negatively charged [Se] n 2n- It is formed by alternating stacking. The unique crystal structure and band structure of two-dimensional bismuth selenide oxide endow it with excellent properties, such as ultra-high carrier mobility, suitable band gap, and small effective mass. Notably, two-dimensional bismuth selenide oxide possesses native high... κ Bismuth selenite gate oxide has an atomically smooth interface comparable to SiO2 / Si. Therefore, two-dimensional bismuth selenite oxide has attracted widespread attention from industry and academia, demonstrating its potential practical value in electronic devices, optoelectronic devices, flexible devices, and memory devices.

[0003] Currently, high-quality bismuth selenide oxide nanosheets and thin films can be obtained on substrates such as mica, strontium titanate, and lanthanum aluminate using methods such as chemical vapor deposition (CVD), molecular beam epitaxy (MBE), pulsed laser deposition (PLD), and metal-organic chemical vapor deposition (MOCVD). It is worth noting that to achieve heterogeneous integration of bismuth selenide oxide with silicon substrates and construct multifunctional optoelectronic devices, it is necessary to develop reliable wafer-level bismuth selenide oxide thin film transfer methods to transfer it non-destructively and cleanly from the growth substrate surface for heterogeneous integration with the target functional substrate. However, existing transfer methods use polymethyl methacrylate (PMMA) as the transfer medium and hydrofluoric acid (HF) wet etching of the substrate, which damages the crystal quality of bismuth selenide oxide and severely affects its properties. Furthermore, these methods can only transfer nanosheets of the micrometer size, resulting in low transfer efficiency. Therefore, developing a non-destructive, clean, wafer-level bismuth selenide oxide thin film transfer method will contribute to the development of bismuth selenide oxide in electronics and optoelectronics.

[0004] Prior art CN116053338A discloses a method based on MoO 3-xA method for fabricating a near-infrared photoelectric sensor with heterogeneous integration of Bi₂O₂Se is disclosed, which involves transferring layered Bi₂O₂Se nanosheets from a mica substrate to a SiO₂ / Si wafer. PMMA is used as the transfer medium, and the substrate is removed by hydrofluoric acid etching to achieve the transfer of Bi₂O₂Se nanosheets. It is evident that existing methods for transferring two-dimensional bismuth selenide oxide thin films do not solve the problem of damage to the crystal quality of bismuth selenide oxide, nor can they improve the transfer efficiency of two-dimensional bismuth selenide oxide thin films. Summary of the Invention

[0005] This invention addresses the shortcomings of current wafer-level bismuth selenide oxide film transfer methods, which suffer from crystal quality damage that severely affects the properties of bismuth selenide oxide and low transfer efficiency. It provides a two-dimensional bismuth selenide oxide film transfer method that achieves non-destructive and clean transfer of wafer-level bismuth selenide oxide films through a specific transfer medium, and improves the transfer efficiency of two-dimensional bismuth selenide oxide films.

[0006] Another object of the present invention is to provide a heterogeneous integration method for two-dimensional bismuth selenide oxide thin films.

[0007] In a first aspect, the present invention provides a method for transferring a two-dimensional bismuth selenide oxide thin film, comprising the following steps: S1. An oxide layer, a stress layer, a support layer and a TRT layer are sequentially formed on the surface of a two-dimensional bismuth selenide oxide film to obtain a composite structure of TRT layer / support layer / stress layer / oxide layer / two-dimensional bismuth selenide oxide / growth substrate; S2. Peel the TRT / support layer / stress layer / oxide layer / two-dimensional bismuth selenide oxide from the surface of the growth substrate, and then transfer the two-dimensional bismuth selenide oxide to the target substrate.

[0008] According to the method for transferring a two-dimensional bismuth selenide oxide thin film provided by the present invention, preferably, the composite structure satisfies at least one of the following conditions: (1) The thickness of the oxide layer is 2~20 nm; (2) The thickness of the stress layer is 300~2000nm; (3) The thickness of the support layer is 1000~3000nm.

[0009] According to the present invention, a method for transferring a two-dimensional bismuth selenide oxide thin film is provided. Preferably, the oxide of the oxide layer in S1 includes hafnium oxide and / or aluminum oxide, and / or, and / or, the stress layer in S1 is any one of Cr layer, Mo layer, Pt layer and Ni layer, and the support layer is Au layer, Ag layer or Cu layer.

[0010] According to the method for transferring a two-dimensional bismuth selenide oxide thin film provided by the present invention, preferably, the oxide layer in S1 is formed in any of the following ways: (1) Atomic layer deposition, the deposition source material for atomic layer deposition is tetra(dimethylamino)hafnium, trimethylaluminum and water, and the growth temperature is 100~250℃; (2) Electron beam evaporation, with a deposition rate of 0.1~5 Å / s.

[0011] According to the present invention, a method for transferring a two-dimensional bismuth selenide oxide thin film is provided. Preferably, the specific operation of transferring the two-dimensional bismuth selenide oxide to the target substrate in step S2 is as follows: After peeling off the surface of the growth substrate, a PPC layer and a PDMS layer are sequentially formed on the surface of the two-dimensional bismuth selenide oxide to obtain a TRT layer / support layer / stress layer / oxide layer / two-dimensional bismuth selenide oxide / PPC / PDMS structure. Then, the TRT layer and the support layer / stress layer are removed, and the PDMS layer is attached to the target substrate. After that, the PDMS layer and the PPC layer are removed, and the two-dimensional bismuth selenide oxide is transferred to the target substrate.

[0012] According to the present invention, a method for transferring a two-dimensional bismuth selenide oxide thin film is provided, wherein preferably, the support layer / stress layer is removed by etching with a ferric chloride solution.

[0013] According to the present invention, a method for transferring a two-dimensional bismuth selenide oxide thin film is provided, wherein the etching concentration of the ferric chloride solution is 0.5~2 mol / L and the etching time is 1~5 min.

[0014] According to the present invention, a method for transferring a two-dimensional bismuth selenide oxide thin film is preferably provided in that the PPC layer on the surface of the two-dimensional bismuth selenide oxide is formed as follows: A PPC layer was formed by spin-coating a PPC solution onto a two-dimensional bismuth selenide oxide surface at a spin-coating speed of 1000~10000 rpm and a baking temperature of 50~120℃.

[0015] Secondly, the present invention also provides a heterogeneous integration method for two-dimensional bismuth selenide oxide, wherein the two-dimensional bismuth selenide oxide is transferred to a target substrate using the two-dimensional bismuth selenide oxide thin film transfer method provided by the present invention, thereby realizing the heterogeneous integration of two-dimensional bismuth selenide oxide.

[0016] According to the heterogeneous integration method of two-dimensional bismuth selenide oxide provided by the present invention, preferably, the target substrate includes any one of silicon wafer, silicon oxide wafer, quartz, and polyethylene terephthalate substrate.

[0017] Beneficial effects: The two-dimensional bismuth selenide oxide thin film transfer method provided by this invention achieves non-destructive and clean transfer of bismuth selenide oxide thin films through a composite transfer medium of TRT layer / support layer / stress layer / oxide layer. During the transfer process, the oxide layer acts as a contact layer to ensure that the bismuth selenide oxide is not damaged during the transfer process, thus ensuring its excellent electrical properties. The stress layer provides tensile stress, enabling dry non-destructive peeling of wafer-level bismuth selenide oxide. The support layer can prevent the film from cracking during the peeling process, thus achieving non-destructive and clean transfer of bismuth selenide oxide thin films.

[0018] The bismuth selenide oxide film transferred using the transfer method of the present invention is complete and continuous, with a smooth surface and a surface roughness of less than 0.65 nm. The film has good uniformity, and the growth substrate after dry peeling can be used to repeatedly grow bismuth selenide oxide films. Repeated peeling enables the reuse of the growth substrate. Attached Figure Description

[0019] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0020] Figure 1 This is a schematic diagram of the two-dimensional bismuth selenide oxide wafer transfer method of the present invention.

[0021] Figure 2 The images show the morphology of two-dimensional bismuth selenide oxide after peeling and transfer, and their optical microscope images, where a is the morphology of two-dimensional bismuth selenide oxide after peeling, b is the morphology of two-dimensional bismuth selenide oxide after transfer, and c is the optical microscope image of the two-dimensional bismuth selenide oxide wafer after transfer.

[0022] Figure 3 The image shows the surface roughness statistics of the bismuth selenide oxide film after transfer in Example 1. The inset image is an atomic force microscope image of the surface of the two-dimensional bismuth selenide oxide film after transfer.

[0023] Figure 4 The image shows the Raman spectrum of the bismuth selenide oxide film after transfer in Example 1.

[0024] Figure 5 The image shows a typical field-effect transistor performance curve of the bismuth selenide oxide thin film after transfer in Example 1.

[0025] Figure 6 Optical images of repeated growth and peeling in Example 2.

[0026] Figure 7 The images show the morphology of the two-dimensional bismuth selenide oxide film after peeling and transfer in Example 3, and their optical microscope images. In the image, a is the morphology of the two-dimensional bismuth selenide oxide film after peeling, b is the morphology of the two-dimensional bismuth selenide oxide film after transfer, and c is the optical microscope image of the two-dimensional bismuth selenide oxide wafer after transfer.

[0027] Figure 8 The images shown are comparative example 1, which includes two-dimensional bismuth selenide oxide morphology images after exfoliation and transfer, and their optical microscope images. In example a, the two-dimensional bismuth selenide oxide morphology image after exfoliation is shown; in example b, the two-dimensional bismuth selenide oxide morphology image after transfer is shown; and in example c, the two-dimensional bismuth selenide oxide wafer optical microscope image after transfer is shown.

[0028] Figure 9 Comparative Example 2 shows the morphology of the two-dimensional bismuth selenide oxide film after peeling and transfer, and their optical microscope images. In the image, a is the morphology of the two-dimensional bismuth selenide oxide film after peeling, b is the morphology of the two-dimensional bismuth selenide oxide film after transfer, and c is the optical microscope image of the two-dimensional bismuth selenide oxide wafer after transfer. Detailed Implementation

[0029] The following examples are for illustrative purposes only and are not intended to limit the scope of the invention. Where specific techniques or conditions are not specified in the examples, they should be performed according to the techniques or conditions described in the literature in this field, or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased from legitimate channels.

[0030] Abbreviation: TRT: Heat Release Tape; PPC: Polypropylene carbonate; PDMS: Polydimethylsiloxane membrane.

[0031] In a specific embodiment, the present invention provides a method for transferring a two-dimensional bismuth selenide oxide thin film, comprising the following steps: S1. An oxide layer, a stress layer, a support layer and a TRT layer are sequentially formed on the surface of a two-dimensional bismuth selenide oxide film to obtain a composite structure of TRT layer / support layer / stress layer / oxide layer / two-dimensional bismuth selenide oxide / growth substrate; S2. Peel the TRT / support layer / stress layer / oxide layer / two-dimensional bismuth selenide oxide from the surface of the growth substrate, and then transfer the two-dimensional bismuth selenide oxide to the target substrate.

[0032] It should be noted that: In the two-dimensional bismuth selenide oxide thin film transfer method provided by the present invention, a composite transfer medium consisting of a TRT layer, a support layer, a stress layer, and an oxide layer is formed on the surface of the two-dimensional bismuth selenide oxide thin film. The oxide layer in the composite transfer medium acts as a contact layer to ensure that the bismuth selenide oxide is not damaged during the transfer process and to guarantee its excellent electrical properties. The stress layer provides tensile stress, enabling dry non-destructive peeling of wafer-level bismuth selenide oxide. The support layer increases the toughness of the stress layer and prevents cracks from forming in the support layer / stress layer during the peeling process. The TRT layer acts as a self-supporting layer to facilitate the transfer operation. Through the action of the TRT layer, the support layer / stress layer / oxide layer / two-dimensional bismuth selenide oxide as a whole can be peeled off from the growth substrate surface without damage and cleanly. Then, combined with the bonding medium, it is transferred to a new target substrate.

[0033] The two-dimensional bismuth selenide oxide film mentioned in this invention is preferably a wafer-level two-dimensional bismuth selenide oxide film, which can achieve non-destructive and clean transfer of large-size wafer-level two-dimensional bismuth selenide oxide films of two inches or more.

[0034] In specific embodiments, the oxide layer mentioned in this invention is an oxide resistant to corrosion by oxidizing acidic solutions such as ferric chloride. To better protect the oxide layer's resistance to corrosion by oxidizing acidic solutions such as ferric chloride and prevent ferric chloride from penetrating the oxide layer and damaging bismuth selenide oxide, the thickness of the oxide layer in the composite structure mentioned in this invention is preferably 2~20 nm, more preferably 3~10 nm, for example, it can be a value of 2 nm, 4 nm, 5 nm, 6 nm, 8 nm, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm or 20 nm or any range thereof. Meanwhile, if the oxide layer thickness is too thick, it will increase the rigidity of the oxide / bismuth selenide oxide, which is not conducive to conformal bonding to the target substrate and is prone to breakage. Therefore, the thickness is preferably no more than 20 nm.

[0035] In a specific embodiment, the growth temperature of the oxide layer is preferably 100~250℃, more preferably 100~150℃.

[0036] In order to provide sufficient strain energy to peel off the bismuth selenide oxide film without increasing the time for depositing the metal film, the thickness of the stress layer in the composite structure mentioned in this invention is preferably 300~2000nm, more preferably 500~1000nm, for example, it can be a point value of 300nm, 500nm, 800nm, 1000nm, 1200nm, 1500nm, 1800nm ​​or 2000nm or any range thereof.

[0037] Similarly, to avoid cracking during the peeling of the bismuth selenium oxide film without increasing the coating time, the thickness of the support layer in the composite structure mentioned in this invention is preferably 1000~3000nm, more preferably 1500~2000nm, for example, it can be a point value of 1000nm, 1200nm, 1500nm, 1800nm, 2000nm, 2200nm, 2500nm, 2800nm ​​or 3000nm or any range thereof.

[0038] In the composite structure mentioned in this invention, the thickness of the oxide layer, the thickness of the stress layer, and the thickness of the support layer can be individually optimized or jointly optimized. A more preferred embodiment is to simultaneously and synergistically optimize the thickness of the oxide layer, the thickness of the stress layer, and the thickness of the support layer.

[0039] In a specific embodiment, the oxide layer of the present invention serves as a contact layer, which ensures that bismuth selenide oxide is protected from damage during the transfer process and guarantees its excellent electrical properties. Any oxide in the art that can achieve this function can be used as the material of the oxide layer of the present invention, such as hafnium oxide and / or aluminum oxide.

[0040] In specific embodiments, the stress layer provided by this invention serves to provide tensile stress, enabling dry, non-destructive peeling of wafer-level bismuth selenide oxide. The support layer provided by this invention serves to prevent cracking of the film during the peeling process. Similarly, any material in the art capable of achieving the corresponding functions can be used to prepare the stress layer and support layer of this invention. For example, the stress layer in S1 is any one of a Cr layer, a Mo layer, a Pt layer, and a Ni layer, and the support layer is an Au layer, an Ag layer, or a Cu layer.

[0041] In specific implementations, for example, a nickel layer can be preferred as the stress layer and a copper layer as the support layer.

[0042] The materials of the stress layer and the support layer mentioned in this invention can be selected individually or in combination, and a more preferred embodiment is to select them simultaneously and synergistically.

[0043] For example, in a specific embodiment, the stress layer is preferably a nickel layer with a thickness of 500 nm, and the support layer is a copper layer with a thickness of 1500 nm. The stress layer and the support layer can be formed by magnetron sputtering deposition.

[0044] In specific embodiments, the method of forming the oxide layer in S1 of the present invention is not specifically limited, and the oxide layer can be formed in any manner achievable in the art. For example, any of the following formation methods can be used: (1) Atomic layer deposition, the deposition source material for atomic layer deposition is tetra(dimethylamino)hafnium, trimethylaluminum and water, and the growth temperature is 100~250℃; (2) Electron beam evaporation, with a deposition rate of 0.1~5 Å / s.

[0045] In a specific embodiment, the preferred oxide is hafnium oxide, which is formed by atomic layer deposition with a thickness of 5 nm.

[0046] In a specific embodiment, the present invention also provides a specific operation method for transferring two-dimensional bismuth selenide oxide to the target substrate as described in S2: After peeling off the surface of the growth substrate, a PPC layer and a PDMS layer are sequentially formed on the surface of the two-dimensional bismuth selenide oxide to obtain a TRT layer / support layer / stress layer / oxide layer / two-dimensional bismuth selenide oxide / PPC / PDMS structure. Then, the TRT layer and the support layer / stress layer are removed, and the PDMS layer is attached to the target substrate. After that, the PDMS layer and the PPC layer are removed, and the two-dimensional bismuth selenide oxide is transferred to the target substrate.

[0047] In some specific implementations, the transfer of two-dimensional bismuth selenide oxide to the target substrate more preferably includes the following steps: S1. An oxide layer is coated on the surface of a two-dimensional bismuth selenide oxide film, followed by the deposition of a stress layer and a support layer, and then thermal release tape (TRT) is applied to obtain a composite structure of "TRT / stress layer / support layer / oxide / two-dimensional bismuth selenide oxide / growth substrate". S2. Dryly peel off TRT / stress layer / support layer / oxide / two-dimensional bismuth selenide oxide from the growth substrate surface, and then spin-coat a layer of polypropylene carbonate (PPC) on the surface of two-dimensional bismuth selenide oxide to obtain the composite structure II of "TRT / metal / oxide / two-dimensional bismuth selenide oxide / PPC"; Polydimethylsiloxane (PDMS) film was bonded to the surface of PPC in composite structure two. The TRT was released by heating. Then, the metal was etched with ferric chloride solution to remove the stress layer / support layer. After cleaning and drying, composite structure three of "PDMS / PPC / two-dimensional bismuth selenide oxide / oxide" was obtained. The composite structure was bonded to the target substrate, heated to release PDMS, and then PPC was removed using an organic solvent after baking.

[0048] In a specific embodiment, the two-dimensional bismuth selenide oxide film mentioned in S1 of the present invention is preferably a two-dimensional bismuth selenide oxide film with a thickness of 3-15 nm grown on a substrate such as sapphire or strontium titanate by chemical vapor deposition, and the film size is preferably 2 inches or more. More preferably, the thickness of the bismuth selenide oxide film is 10 nm, and the growth substrate is sapphire.

[0049] In a specific embodiment, the dry peeling method mentioned in S2 of the present invention is preferably dry mechanical peeling, with TRT serving as a self-supporting layer to apply external stress, so that the two-dimensional bismuth selenide oxide film is completely separated from the growth substrate.

[0050] This invention does not impose specific limitations on the removal method of the TRT layer and the support / stress layer. Any removal method that ensures the two-dimensional bismuth selenide oxide film is acceptable. In some specific embodiments, the support / stress layer mentioned in this invention can be removed by etching with ferric chloride solution.

[0051] In other specific embodiments, in order to more thoroughly etch the metal of the support layer / stress layer without damaging the two-dimensional bismuth selenide oxide film, the present invention further preferably uses a ferric chloride solution with an etching concentration of 0.5~2 mol / L for etching the support layer / stress layer, and the etching time is preferably 1~5 min. For example, the etching concentration can be a point value of 0.5 mol / L, 0.8 mol / L, 1.0 mol / L, 1.5 mol / L, 1.8 mol / L, 2 mol / L or any range thereof, and the etching time can be a point value of 1 min, 2 min, 3 min, 4 min, 5 min or any range thereof.

[0052] In some specific embodiments, the preferred etching concentration of ferric chloride solution is 1 mol / L, and the etching time is 5 min.

[0053] In some specific embodiments, after the stress layer / support layer is removed by etching with ferric chloride solution, the cleaning and drying process is preferably repeated 3 to 5 times, with each cleaning session lasting 15 minutes.

[0054] In some specific embodiments, the two-dimensional bismuth selenide oxide surface PPC layer mentioned in this invention is formed in the following ways: A PPC layer is formed by spin-coating a PPC solution onto a two-dimensional bismuth selenide oxide surface. The spin-coating speed is 1000~10000 rpm, preferably 2000~6000 rpm, and the baking temperature for solidifying the adhesive is 50~120℃, preferably 60~80℃.

[0055] The spin coating speed can be, for example, a point value such as 1000rpm, 3000rpm, 5000rpm, 8000rpm, 10000rpm, or any range thereof, and the baking temperature can be, for example, a point value such as 50℃, 80℃, 100℃, 120℃, or any range thereof.

[0056] In a specific embodiment, the solvent of the PPC solution mentioned in S2 of the present invention can be anisole or the like, and the concentration of the PPC solution can be 2 to 6 wt%, for example, it can be a point value of 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, or any range of values.

[0057] In a specific implementation, the preferred process parameters for spin-coated PPC are as follows: The PPC solution uses anisole as the solvent, with a concentration of 4 wt%, spin coating speed of 2000 pm, and baking temperature of 80℃.

[0058] In a specific embodiment, the PDMS layer mentioned in S2 of the present invention can preferably be formed by roll bonding.

[0059] In a specific embodiment, the heating temperature for releasing PDMS mentioned in S2 of the present invention is 160~200℃, for example, it can be a point value such as 160℃, 170℃, 180℃, 190℃, 200℃ or any range of values.

[0060] In a specific embodiment, the heating temperature mentioned in S2 of the present invention to release the TRT is 90~150℃, preferably 100~120℃, for example, it can be a point value or any range value composed of 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, etc.

[0061] In a specific embodiment, the organic solvent used to remove PPC after baking mentioned in S2 of the present invention can be, for example, UP grade or HPLC purity acetone or N-methylpyrrolidone. The baking temperature is preferably 150°C and the baking time is 15 min.

[0062] The two-dimensional bismuth selenide oxide film transferred using the method of the present invention is complete and continuous with a surface roughness of 0.63 nm. A two-inch non-destructive and clean bismuth selenide oxide wafer can be obtained, and a large-area transfer of two-dimensional bismuth selenide oxide film can be achieved in one go with higher transfer efficiency.

[0063] In a specific embodiment, the present invention also provides a heterogeneous integration method for two-dimensional bismuth selenide oxide, which uses the two-dimensional bismuth selenide oxide thin film transfer method provided by the present invention to transfer two-dimensional bismuth selenide oxide to a target substrate, thereby realizing the heterogeneous integration of two-dimensional bismuth selenide oxide.

[0064] In specific embodiments, the heterogeneous integration method of the present invention for two-dimensional bismuth selenide oxide is applicable to transferring two-dimensional bismuth selenide oxide thin films to a variety of different target substrates, and can also realize heterogeneous integration of a variety of different substrates with two-dimensional bismuth selenide oxide, such as any one of silicon wafers, silicon oxide wafers, quartz, sapphire, and polyethylene terephthalate substrates.

[0065] Example 1 A method for transferring two-dimensional bismuth oxide thin films, such as... Figure 1 As shown, it includes the following steps: S1. Using atomic layer deposition, a 5nm hafnium oxide layer was grown on the surface of a two-inch two-dimensional bismuth selenide / sapphire wafer with tetra(dimethylamino)hafnium and water as raw materials at a growth temperature of 100℃. Then, magnetron sputtering was used to sequentially sputter a 500 nm stress layer of nickel and a 1500 nm support layer of copper onto the surface of the hafnium oxide layer; Then, a roller press is used to bond the heat release tape TRT layer to the copper surface of the support layer to obtain a "TRT / copper / nickel / hafnium oxide / two-dimensional bismuth selenide oxide / sapphire" composite structure; S2. The "TRT / copper / nickel / hafnium oxide / two-dimensional bismuth selenide oxide" composite structure was separated from the sapphire using a mechanical dry stripping method (the morphology of the separated two-dimensional bismuth selenide oxide is as follows). Figure 2 (as shown) Commercially available polypropylene carbonate (weight average molecular weight 200,000-300,000) was dissolved in anisole at a mass fraction of 4 wt%. The PPC was then uniformly spin-coated onto the surface of two-dimensional bismuth selenide oxide using a spin coater at a speed of 2000 rpm and cured by baking on a hot plate at 80°C for 3 minutes. PDMS was bonded to the PPC surface using a roller press, and then TRT was released on a hot stage at 120°C. The metal (copper / nickel layer) was then completely etched using a 1 mol / L ferric chloride solution, and the surface was rinsed with deionized water 5 times for 10 min each time. Finally, a roll press was used to bond the "PDMS / PPC / 2D bismuth selenide oxide / hafnium oxide" to the surface of a silicon oxide / silicon substrate. PDMS was released on a hot stage at 180°C, followed by removal of PPC using acetone, yielding 2D bismuth selenide oxide / hafnium oxide / silicon oxide / silicon. The morphology of the transferred 2D bismuth selenide oxide is as follows. Figure 2 As shown.

[0066] Transferred two-dimensional bismuth oxide thin film Figure 3 As shown, its surface is flat, clean and uniform, and the surface roughness statistics show that the surface roughness is less than 0.65nm. Figure 4 The image shows the Raman spectrum of the transferred bismuth selenide oxide film. The Raman spectrum indicates that the film has good uniformity after transfer.

[0067] The electrical properties of the transferred two-dimensional bismuth selenide oxide film are as follows: Figure 5 As shown, field-effect transistors (FETs) were fabricated using standard micro / nano fabrication processes such as electron beam lithography. Figure 5 (Inset image), the results show that the transferred two-dimensional bismuth selenide oxide film has excellent electrical properties, with an electron mobility of up to 150 cm⁻¹. 2 V -1 s -1 .

[0068] Example 2 A method for transferring two-dimensional bismuth oxide thin films, such as... Figure 1 As shown, it includes the following steps: S1. Using atomic layer deposition, a 5nm hafnium oxide layer was grown on the surface of a two-inch two-dimensional bismuth selenide / sapphire wafer (the thickness of the two-dimensional bismuth selenide film was 10nm) using tetra(dimethylamino)hafnium and water as raw materials at a growth temperature of 100℃. Then, magnetron sputtering was used to sequentially sputter a 500 nm stress layer of nickel and a 1500 nm support layer of copper onto the surface of the hafnium oxide layer; Then, a roller press is used to bond the heat release tape TRT layer to the copper surface of the support layer to obtain a "TRT / copper / nickel / hafnium oxide / two-dimensional bismuth selenide oxide / sapphire" composite structure; S2. Using a mechanical dry stripping method, the "TRT / copper / nickel / hafnium oxide / two-dimensional bismuth selenide oxide" composite structure is separated from the sapphire, and the two-dimensional bismuth selenide oxide / hafnium oxide / silicon oxide / silicon is obtained by transferring it according to the steps of Example 1; The stripped sapphire is reused to grow two-dimensional bismuth selenide oxide, and stripped again using the same process. Then, following the steps in Example 1, a two-dimensional bismuth selenide oxide / hafnium oxide / silicon oxide / silicon is obtained. This method allows for at least three repeated growth and stripping processes. Figure 6 It can be seen that the surface remains flat, clean and uniform even after multiple growth and peeling processes.

[0069] Example 3 A method for transferring two-dimensional bismuth oxide thin films, such as... Figure 1 As shown, it includes the following steps: S1. Using atomic layer deposition, a 10 nm hafnium oxide layer was grown on the surface of a two-inch two-dimensional bismuth selenide / sapphire wafer (with a two-dimensional bismuth selenide thin film thickness of 8 nm) using tetra(dimethylamino)hafnium and water as raw materials at a growth temperature of 100 °C. Then, magnetron sputtering was used to sequentially sputter a 1000 nm stress layer of nickel and a 1000 nm support layer of copper onto the surface of the hafnium oxide layer; Then, a roller press is used to bond the heat release tape TRT layer to the copper surface of the support layer to obtain a "TRT / copper / nickel / hafnium oxide / two-dimensional bismuth selenide oxide / sapphire" composite structure; S2. Using a mechanical dry stripping method, the "TRT / copper / nickel / hafnium oxide / two-dimensional bismuth selenide oxide" composite structure is separated from the sapphire, and the two-dimensional bismuth selenide oxide / hafnium oxide / silicon oxide / silicon is obtained by transferring it according to the steps of Example 1.

[0070] like Figure 7 As shown, the transferred two-dimensional bismuth selenide oxide film is continuous, intact, and clean, demonstrating the reliability of this method.

[0071] Comparative Example 1 A method for transferring a two-dimensional bismuth selenide oxide thin film includes the following steps: S1. A 300nm nickel layer was sputtered onto a 2-inch two-dimensional bismuth selenide / sapphire wafer (10nm bismuth selenide film thickness) using magnetron sputtering. Then, a heat-release tape (TRT) was applied to the nickel surface using a roll press, and the "TRT / nickel / two-dimensional bismuth selenide" composite structure was separated from the sapphire using a dry mechanical peeling method. Figure 8 As shown; Commercially available polypropylene carbonate (weight average molecular weight 200,000-300,000) was dissolved in anisole at a mass fraction of 4 wt%. The PPC was then uniformly spin-coated onto a two-dimensional bismuth selenide oxide surface using a spin coater at 2000 rpm and cured on a hot plate at 80°C for 3 minutes. PDMS was then bonded to the PPC surface using a roller press. TRT was then released on a hot plate at 120°C. The metal was then completely etched using a 1 mol / L ferric chloride solution and washed five times with deionized water for 10 minutes each time. Finally, the "PDMS / PPC / two-dimensional bismuth selenide oxide" was bonded to a silicon oxide / silicon substrate using a roller press. PDMS was released on a hot plate at 180°C. The PPC was then removed using acetone, yielding a two-dimensional bismuth selenide oxide / silicon oxide / silicon substrate. Figure 8 As shown.

[0072] from Figure 8 It can be seen that the surface of the two-dimensional bismuth selenide oxide film after peeling in the transfer method has cracks and the etching solution is damaged in some areas after transfer. It is impossible to obtain a two-dimensional bismuth selenide oxide film with a smooth, clean and uniform surface. The quality of the two-dimensional bismuth selenide oxide film is damaged, which seriously affects its electrical properties.

[0073] Comparative Example 2 A method for transferring two-dimensional bismuth oxide thin films, such as... Figure 1 As shown, it includes the following steps: S1. Using atomic layer deposition, a 25 nm hafnium oxide layer was grown on the surface of a two-inch two-dimensional bismuth selenide / sapphire wafer (the thickness of the two-dimensional bismuth selenide film was 10 nm) using tetra(dimethylamino)hafnium and water as raw materials at a growth temperature of 100 °C. Then, magnetron sputtering was used to sequentially sputter an 800 nm stress layer of nickel and a 2000 nm support layer of copper onto the surface of the hafnium oxide layer; Then, a roller press is used to bond the heat release tape TRT layer to the copper surface of the support layer to obtain a "TRT / copper / nickel / hafnium oxide / two-dimensional bismuth selenide oxide / sapphire" composite structure; S2. Using a mechanical dry stripping method, the "TRT / copper / nickel / hafnium oxide / two-dimensional bismuth selenide oxide" composite structure is separated from the sapphire, and the two-dimensional bismuth selenide oxide / hafnium oxide / silicon oxide / silicon is obtained by transferring it according to the steps of Example 1.

[0074] like Figure 9As shown, the 800nm ​​stress layer and the 2000nm support layer can achieve non-destructive peeling of two-dimensional bismuth selenide oxide. However, the transferred two-dimensional bismuth selenide oxide has macroscopic damage and a large number of microscopic cracks. This is because the 25nm thick hafnium oxide increases the rigidity of the composite film, and the two-dimensional bismuth selenide oxide cannot conformally adhere to the target substrate, thus leading to damage.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for transferring a two-dimensional bismuth selenide oxide thin film, characterized in that, Includes the following steps: S1. An oxide layer, a stress layer, a support layer and a TRT layer are sequentially formed on the surface of a two-dimensional bismuth selenide oxide film to obtain a composite structure of TRT layer / support layer / stress layer / oxide layer / two-dimensional bismuth selenide oxide / growth substrate; S2. Peel the TRT / support layer / stress layer / oxide layer / two-dimensional bismuth selenide oxide from the surface of the growth substrate, and then transfer the two-dimensional bismuth selenide oxide to the target substrate.

2. The method for transferring a two-dimensional bismuth selenide oxide thin film according to claim 1, characterized in that, The composite structure must satisfy at least one of the following conditions: (1) The thickness of the oxide layer is 2~20 nm; (2) The thickness of the stress layer is 300~2000nm; (3) The thickness of the support layer is 1000~3000nm.

3. The method for transferring a two-dimensional bismuth selenide oxide thin film according to claim 1, characterized in that, The oxide layer in S1 includes hafnium oxide and / or aluminum oxide, and / or the stress layer in S1 is any one of Cr layer, Mo layer, Pt layer and Ni layer, and the support layer is Au layer, Ag layer or Cu layer.

4. The method for transferring a two-dimensional bismuth selenide oxide thin film according to claim 1, characterized in that, The oxide layer described in S1 is formed in any of the following ways: (1) Atomic layer deposition, the deposition source material for atomic layer deposition is tetra(dimethylamino)hafnium, trimethylaluminum and water, and the growth temperature is 100~250℃; (2) Electron beam evaporation, with a deposition rate of 0.1~5 Å / s.

5. The method for transferring the two-dimensional bismuth selenide oxide thin film according to any one of claims 1 to 4, characterized in that, The specific operation for transferring two-dimensional bismuth selenide oxide to the target substrate as described in S2 is as follows: After peeling off the surface of the growth substrate, a PPC layer and a PDMS layer are sequentially formed on the surface of the two-dimensional bismuth selenide oxide to obtain a TRT layer / support layer / stress layer / oxide layer / two-dimensional bismuth selenide oxide / PPC / PDMS structure. Then, the TRT layer and the support layer / stress layer are removed, and the PDMS layer is attached to the target substrate. After that, the PDMS layer and the PPC layer are removed, and the two-dimensional bismuth selenide oxide is transferred to the target substrate.

6. The method for transferring a two-dimensional bismuth selenide oxide thin film according to claim 5, characterized in that, The support layer / stress layer is removed by etching with ferric chloride solution.

7. The method for transferring a two-dimensional bismuth selenide oxide thin film according to claim 6, characterized in that, The etching concentration of the ferric chloride solution is 0.5~2 mol / L, and the etching time is 1~5 min.

8. The method for transferring a two-dimensional bismuth selenide oxide thin film according to claim 5, characterized in that, The PPC layer on the surface of the two-dimensional bismuth selenium oxide is formed as follows: A PPC layer was formed by spin-coating a PPC solution onto a two-dimensional bismuth selenide oxide surface at a spin-coating speed of 1000~10000 rpm and a baking temperature of 50~120℃.

9. A method for heterogeneous integration of two-dimensional bismuth selenide oxide, characterized in that, The two-dimensional bismuth selenide film is transferred to the target substrate using the transfer method of any one of claims 1 to 8, thereby achieving heterogeneous integration of two-dimensional bismuth selenide.

10. The heterogeneous integration method for two-dimensional bismuth selenide oxide according to claim 9, characterized in that, The target substrate includes any one of silicon wafers, silicon oxide wafers, quartz, and polyethylene terephthalate substrates.

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