Anhydrous liquid for low-dimensional material anhydrous wet transfer and application thereof
By using anhydrous liquid to adjust surface tension in an inert gas atmosphere, the problem of water and oxygen sensitivity of wet transfer methods was solved, realizing high-quality transfer and interface bonding of low-dimensional materials on a variety of substrates, and expanding their application in high-frequency and high-speed electronic devices and circuits.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NO 55 INST CHINA ELECTRONIC SCI & TECHNOLOGYGROUP CO LTD
- Filing Date
- 2024-04-07
- Publication Date
- 2026-07-21
AI Technical Summary
Existing wet transfer methods are limited by water and oxygen, making them unsuitable for materials that are easily soluble in or react with water. Furthermore, low-dimensional materials are sensitive to water and oxygen, which leads to impaired interfacial properties and limits their application in high-frequency and high-speed electronic devices and circuits.
Low-dimensional material transfer is performed using anhydrous liquids, including components such as tribromomethane, formamide, phenol, glycerol, methylpyrrolidone, or quinoline. The surface tension is adjusted and the transfer is carried out in an inert gas atmosphere to avoid contact with water and oxygen. The surface tension is used to achieve adhesion between the low-dimensional material and the target substrate.
This method broadens the applicability of wet transfer, improves interface quality, avoids the scattering of charge carriers by water and oxygen impurities, and enables the fabrication of high-mobility field-effect transistors and high-quality van der Waals heterojunction vertical diodes, laying the foundation for the development of high-frequency and high-speed electronic devices and circuits.
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Figure CN118343688B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a wet transfer method for low-dimensional materials, and more particularly to an anhydrous liquid for the anhydrous wet transfer of low-dimensional materials and its application. Background Technology
[0002] Low-dimensional materials such as graphene, boron nitride, and molybdenum disulfide possess excellent electrical properties and have enormous application potential in high-frequency, high-speed electronic devices and circuits. Their unique van der Waals bonding allows for the integration of low-dimensional materials (especially low-dimensional single-crystal materials) onto any substrate. Wet transfer technology is currently the mainstream method for large-area transfer of low-dimensional materials. The surface tension of water helps the adhesion between low-dimensional materials and the substrate, offering a significant advantage over dry transfer in terms of interface bonding. However, the presence of water greatly limits its applicability. For example, materials that are easily soluble in water or react with water (such as water-soluble substrates like strontium aluminate) cannot be used as target substrates. Furthermore, the presence of water prevents the use of common commercial glove boxes to avoid oxygen, thus also preventing the use of oxygen-reactive materials (such as metals like titanium and aluminum, and low-dimensional materials like black phosphorus) as target substrates. As research into low-dimensional systems deepens, it has been discovered that water and oxygen are major bottlenecks limiting the performance of low-dimensional materials. For some substrate materials with special surface modifications, the easy adsorption of water and oxygen makes it impossible to obtain high-quality heterostructures using this method. Furthermore, the electrical properties of low-dimensional materials are extremely sensitive to the surface; water and oxygen impurities at the interface will scatter charge carriers and generate interface states that affect the Fermi level. These problems significantly limit the realization and application of the superior performance of low-dimensional materials. Summary of the Invention
[0003] Purpose of the invention: The purpose of this invention is to provide an anhydrous liquid for the anhydrous wet transfer of low-dimensional materials in order to improve the transfer performance of low-dimensional materials and broaden the application scope of wet transfer of low-dimensional materials; another purpose of this invention is to provide the application of the above-mentioned anhydrous liquid in the transfer of low-dimensional materials.
[0004] Technical solution: The anhydrous liquid for anhydrous wet transfer of low-dimensional materials according to the present invention comprises 60%-100% component A and 0-40% component B by mass percentage; wherein component A comprises one or more of tribromomethane, formamide, phenol, glycerol, methylpyrrolidone, and quinoline; wherein component B comprises one or more of acetone, ethanol, isopropanol, anisole, chloroform, and toluene.
[0005] Furthermore, tribromomethane, formamide, phenol, glycerol, methylpyrrolidone, or quinoline liquids all have surface tension coefficients greater than 30 mN / m at room temperature. However, some components have poor fluidity, which is not conducive to the removal of residual liquid at the interface during the transfer process. Adding acetone, ethanol, isopropanol, anisole, chloroform, or toluene, which have low surface tension, balances surface tension and liquid phase fluidity. When the surface tension coefficient of the anhydrous liquid reaches 30 mN / m or higher, on the one hand, the surface tension can provide sufficient buoyancy for the low-dimensional material to float on the surface of the anhydrous liquid; on the other hand, the surface tension can improve the wetting angle between the anhydrous liquid and the target substrate, making it easier to remove rather than adhere to the target substrate surface.
[0006] Furthermore, the surface tension of the anhydrous liquid can be adjusted by regulating the temperature. The surface tension coefficient can be precisely controlled by the liquid temperature to achieve a better bonding effect.
[0007] The anhydrous wet transfer method for low-dimensional materials using the anhydrous liquid described in this invention includes the following steps:
[0008] (S1) A support layer is formed on the surface of a low-dimensional material on a substrate;
[0009] (S2) Separate the low-dimensional material and support layer as a whole from the substrate, and transfer the low-dimensional material and support layer as a whole into an anhydrous liquid protected by an inert gas atmosphere;
[0010] (S3) Using the target substrate, the low-dimensional material and the support layer are lifted out of the anhydrous liquid as a whole, and the residual anhydrous liquid between the low-dimensional material and the target substrate is removed to make the low-dimensional material adhere to the target substrate.
[0011] (S4) Remove the support layer to achieve wet transfer of low-dimensional materials from the initial substrate to the target substrate.
[0012] Furthermore, the wetting angle between the anhydrous liquid and the target substrate to be transferred is ≥90°, and the residual anhydrous liquid does not wet the target substrate. Under the action of surface tension, the residual anhydrous liquid is easy to move under the action of external force rather than adhere to the surface of the target substrate, which is beneficial to the bonding of low-dimensional materials with the target substrate and the removal of residual anhydrous liquid.
[0013] Furthermore, the support layer in step (S1) includes one or more combinations of metals and insulating dielectrics. The anhydrous liquid will not chemically react with the low-dimensional material to be transferred or the target substrate to be transferred, ensuring the non-destructive nature of the transfer. The anhydrous liquid has a certain solubility for organic matter, and the use of inorganic materials such as metals and insulating dielectrics as support layers is applicable to these anhydrous liquids, greatly expanding the range of selectable and controllable anhydrous liquids. The specific methods for separating the low-dimensional material and the support layer as a whole from the substrate include one or more of the following: wet etching of the substrate, surface modification, and mechanical peeling of the low-dimensional material from the substrate. Most desorption methods are applicable and can be optimized according to the bonding between the low-dimensional material and the substrate. When some support layers can be directly used as functional layers in the subsequent device fabrication process, they do not need to be completely removed. This enables high-mobility field-effect transistors and high-quality van der Waals heterojunction vertical diodes made of low-dimensional materials, laying the foundation for the development of high-frequency and high-speed electronic devices and circuits.
[0014] Furthermore, the inert gas atmosphere mentioned in step (S2) includes one or more of nitrogen, argon, and helium, which further removes trace amounts of water or oxygen introduced during the transfer process, avoids the formation of water and oxygen doping, and obtains a more intrinsic and high-quality heterogeneous interface. At the same time, the range of target substrates is expanded, including not only conventional single-crystal, polycrystalline, and amorphous substrates, but also composite substrates with attached functional structures, such as composite substrates with a water-soluble layer on the surface, vertical heterogeneous structure devices with easily oxidizable two-dimensional materials on the surface, and lateral devices with easily oxidizable metal bottom electrodes on the surface. Most liquids have a certain degree of solubility for air, water, and oxygen. In an air atmosphere, it is difficult to truly prevent water and oxygen from contacting the surface of the target substrate and its interface with low-dimensional materials by relying solely on anhydrous liquids. This method avoids direct contact between air and anhydrous liquid by bonding in an inert gas atmosphere. For trace amounts of water and oxygen that may be introduced into the inert gas atmosphere, the trace amounts of water and oxygen present in the gas components can be fully removed through inert gas purging, circulation purification, physical adsorption, and chemical reaction. The trace amounts of water and oxygen present in the liquid components can be fully removed through liquid homogeneous exchange diffusion, heterogeneous miscibility, static stratification based on density difference, phase change, physical adsorption, and chemical reaction, ultimately achieving an industrial-grade anhydrous and oxygen-free standard for water and oxygen content.
[0015] Further, step (S3) includes immersing the target substrate, low-dimensional material, and support layer as a whole into the auxiliary bonding liquid, and then removing the residual auxiliary bonding liquid by pressure expulsion or heating evaporation. During the process of retrieving the low-dimensional material and support layer from the anhydrous liquid using the target substrate, the residual anhydrous liquid does not wet the target substrate due to surface tension. The residual anhydrous liquid moves under external force, simultaneously causing the low-dimensional material to conformally adhere to the target substrate, and is removed by pressure expulsion, heating evaporation, or other methods. Alternatively, the target substrate, low-dimensional material, and support layer are placed entirely into the auxiliary bonding liquid, where partial liquid exchange reduces viscosity, and then the liquid is retrieved and the residual auxiliary bonding liquid is removed by pressure expulsion, heating evaporation, or other methods.
[0016] Furthermore, the auxiliary bonding liquid includes one or more of acetone, ethanol, anisole, and toluene. The auxiliary bonding liquid itself has insufficient surface tension coefficient to support the suspension of most low-dimensional materials and their supporting layers. For highly viscous and relatively difficult-to-remove anhydrous liquids, by immersing the target substrate, low-dimensional material, and supporting layer as a whole in the auxiliary bonding liquid and then retrieving them, the residual anhydrous liquid between the low-dimensional material and the target substrate can be replaced with the auxiliary bonding liquid through mutual dissolution and exchange. The residual auxiliary bonding liquid can then be more easily removed by pressure expulsion or heating to evaporate. Simultaneously, based on surface activity matching, it is expected to achieve interface modification for specific functions, such as controlling the carrier transport performance at the heterojunction interface, further expanding the design space of wet transfer methods.
[0017] This invention provides an application of anhydrous liquids in the anhydrous wet transfer process of low-dimensional materials. It is applicable to target substrates whose surfaces readily adsorb water, dissolve in water, react with water, readily adsorb oxygen, or are oxidized, or to surface films, functional microstructures, heterostructures, and bottom electrode devices composed of these materials. This overcomes the limitations of wet transfer on materials and functional structures sensitive to or easily reacting with water and oxygen, thus improving interfacial performance. Simultaneously, the substrate is unrestricted during the transfer process, eliminating the need to consider the adhesion between the low-dimensional material and the substrate, thus broadening its applicability. Low-dimensional materials include one or more of graphene, boron nitride, indium tin oxide, transition metal chalcogenides, oxides, nitrides, and carbon nanotubes, with a thickness of 0.3 nm to 500 nm. Specific methods for forming a support layer on the surface of the low-dimensional material include growth, deposition, spin coating, or droplet curing.
[0018] Beneficial Effects: Compared with existing technologies, this invention has the following significant advantages: 1. It broadens the applicability of wet transfer, with no restrictions on substrate materials, and is especially suitable for materials whose surfaces easily adsorb, dissolve, or react with water or oxygen, such as target substrates with a water-soluble layer on the surface. During the entire transfer process, the target substrate can avoid contact with water and oxygen. 2. It provides excellent interface bonding, offering an effective technical approach for the large-area construction of van der Waals heterojunctions, improving the interface quality after the transfer of low-dimensional materials, and avoiding the scattering of interface carriers by water or oxygen impurities, thus affecting interface performance. 3. By adjusting the surface tension of the anhydrous liquid through parameters such as solution ratio and temperature, the key role of surface tension in automatically driving away the liquid and smoothing the interface during bonding is fully utilized, achieving conformal bonding of low-dimensional materials on the target substrate surface. 4. It enables the fabrication of high-mobility field-effect transistors and high-quality van der Waals heterojunction vertical diodes from low-dimensional materials, laying the foundation for the development of high-frequency and high-speed electronic devices and circuits. 5. This modified transfer method is simple, easy to control, and the anhydrous liquid can be reused, resulting in low production costs and easy promotion. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the wet transfer process for low-dimensional materials according to the present invention;
[0020] Figure 2 This is a schematic diagram of the product structure for transferring hexagonal boron nitride to a diamond substrate using the aqueous solution method of Example 6 of the present invention;
[0021] Figure 3 This is a schematic diagram of the product structure of graphene transferred to a strontium aluminate / strontium titanate substrate using the aqueous solution method of Example 7 of the present invention;
[0022] Figure 4 This is a schematic diagram of the product structure of the molybdenum disulfide / graphene van der Waals heterojunction vertical diode directly realized by transfer using the aqueous solution of Example 8 according to the present invention. Detailed Implementation
[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings.
[0024] Examples 1-11
[0025] Anhydrous liquids with different components and ratios are prepared, as detailed in Table 1.
[0026] Table 1 Anhydrous liquids with different proportions
[0027] 1 60% Glycerol 20% ethanol and 20% isopropanol 2 60% Glycerol 40% ethanol 3 60% Glycerol 40% Isopropanol 4 80% Methylpyrrolidone 20% Anisole 5 70% Phenol 29% chloroform, 1% ethanol 6 100% Methylpyrrolidone - 7 Glycerol 67% 33% ethanol 8 67% Phenol 33% ethanol 9 90% quinoline 10% acetone 10 100% formamide - 11 75% tribromomethane 25% Toluene
[0028] The method for wet transfer of low-dimensional materials using the anhydrous liquid of the above embodiments includes the following steps:
[0029] (S1) A support layer 21 is formed on the surface of the low-dimensional material 20 on the substrate 10;
[0030] (S2) Separate the low-dimensional material 20 and the support layer 21 as a whole from the substrate 10, and transfer the low-dimensional material 20 and the support layer 21 as a whole into an anhydrous liquid protected by an inert gas atmosphere.
[0031] (S3) Using the target substrate 40, the low-dimensional material 20 and the support layer 21 are lifted out of the anhydrous liquid as a whole, and the residual anhydrous liquid between the low-dimensional material 20 and the target substrate 40 is removed so that the low-dimensional material 20 and the target substrate 40 are bonded together.
[0032] (S4) Remove the support layer 21 to realize the wet transfer of low-dimensional material 20 from the initial substrate 10 to the target substrate 40.
[0033] The specific transfer process of hexagonal boron nitride to a diamond substrate with hydrogen surface terminals using the aqueous solution of Example 6 is as follows:
[0034] (S1) A 5nm thick hexagonal boron nitride layer is grown on a 10mm*10mm copper substrate by chemical vapor deposition, and a 100nm gold layer is deposited on the surface as a support layer.
[0035] (S2) The copper substrate was etched with ammonium persulfate solution to separate the hexagonal boron nitride and gold support layer from the copper substrate. The hexagonal boron nitride and gold support layer were lifted from the ammonium persulfate solution using a sapphire temporary carrier and quickly placed into a glass bottle containing a temporary carrier liquid, methylpyrrolidone. The surface tension coefficient of the carrier liquid reached 41 mN / m at room temperature. As the temperature was further reduced to 5-10℃, the surface tension coefficient could be increased to more than 45 mN / m. Under the action of surface tension, the hexagonal boron nitride and gold support layer automatically floated up from the sapphire temporary carrier and suspended on the surface of the anhydrous liquid methylpyrrolidone. The glass bottle was placed in an argon atmosphere glove box (water and oxygen content less than 0.1 ppm) and left to stand for 2 hours. The water and oxygen circulation purification function of the glove box was used to remove any trace amounts of water and oxygen that might have been introduced by the temporary carrier liquid, further reducing the concentration of impurities in the anhydrous liquid.
[0036] (S3) In an argon atmosphere glove box, the temperature of anhydrous liquid methylpyrrolidone is reduced to 5°C using a semiconductor cooling thermostat platform to further increase its surface tension coefficient; hexagonal boron nitride and gold support layer are lifted from methylpyrrolidone using a diamond substrate with hydrogen surface terminals and an area of 10mm*10mm (methylpyrrolidone does not wet the diamond surface); the diamond substrate with hydrogen surface terminals covered with hexagonal boron nitride and gold support layer is placed on a heating stage at 130°C for baking, and the residual anhydrous liquid methylpyrrolidone on the diamond surface is removed by heating and evaporation, and the bonding of hexagonal boron nitride and diamond substrate with hydrogen surface terminals is achieved under the action of the surface tension of methylpyrrolidone;
[0037] (S4) The gold support layer is removed by iodine / potassium iodide solution to achieve wet transfer of hexagonal boron nitride from a copper substrate to a diamond substrate with hydrogen surface terminals; if the gold support layer is retained, it can be used as a gate electrode material for field-effect devices.
[0038] The obtained structure is as follows Figure 2 As shown in the figure, 20 represents hexagonal boron nitride, 40 represents diamond, and 41 represents the hydrogen surface terminal of diamond. The hydrogen surface terminal of diamond has a negative electron affinity, readily adsorbing water and oxygen from the air, which is difficult to remove, affecting its interfacial properties. Methylpyrrolidone was used as the transfer liquid, and bonding was performed in an anhydrous and oxygen-free argon inert atmosphere glove box. This ensured that the interface between hexagonal boron nitride and the hydrogen surface terminal of diamond was completely free from contact with water and oxygen during the bonding process, resulting in a more intrinsic heterogeneous interface. This avoided water and oxygen impurities doping and scattering, and reduced the carrier concentration to 1×10⁻⁶. 12 cm 2 With a migration rate of / Vs or less, the migration rate significantly increases to 200cm. 2 With a value of over / Vs, large-area fabrication of hexagonal boron nitride / hydrogen-terminated diamond heterojunctions was achieved, laying the foundation for the application of enhanced high-voltage devices.
[0039] The specific transfer process of graphene to a strontium aluminate / strontium titanate substrate was carried out using the aqueous solution from Example 7:
[0040] (S1) A single layer of graphene grown on a copper substrate by chemical vapor deposition is spin-coated with PMMA as a support layer.
[0041] (S2) The copper substrate was etched with ferric chloride solution to separate the graphene and PMMA support layer as a whole from the copper substrate. Using a silicon temporary carrier, the graphene and PMMA support layer were lifted from the ammonium persulfate solution and placed in a glycerol / ethanol mixed solution. Glycerol has a surface tension coefficient as high as 63.3 mN / m at room temperature, but its fluidity is slightly poor. Ethanol was added to improve the overall fluidity, and the temperature was controlled at 40℃. The surface tension of the mixed solution was approximately 30–40 mN / m. Under the influence of surface tension, the graphene and PMMA support layer… The graphene and PMMA support layer automatically floated up from the silicon temporary carrier and suspended on the surface of the glycerol / ethanol mixed solution. The container containing the glycerol / ethanol mixed solution was placed in a glove box under a nitrogen atmosphere (water and oxygen content less than 0.1 ppm) and left to stand for 3 hours. The glycerol and ethanol spontaneously separated into layers. The graphene and PMMA support layer floated at the interface between the glycerol and ethanol under the action of surface tension. Because the glycerol was close to its melting point, the trace amounts of dissolved water and oxygen spontaneously migrated to the upper layer of ethanol. The water and oxygen in the solution could be fully removed by adding and removing ethanol.
[0042] (S3) In a glove box under a nitrogen atmosphere, the glycerol / ethanol mixture is heated to 40°C. Using a strontium titanate substrate with a water-soluble strontium aluminate layer grown on its surface, the graphene and PMMA support layer are lifted from the anhydrous liquid glycerol / ethanol mixture (the mixture does not wet the treated strontium aluminate surface) and placed in an auxiliary bonding liquid isopropanol. Through liquid miscibility and exchange, the viscosity of the glycerol / ethanol mixture is reduced, and the residual glycerol / ethanol mixture is fully removed. The strontium aluminate / strontium titanate substrate coated with graphene and PMMA support layer is placed on the operating table, and the residual isopropanol on the surface of the strontium aluminate / strontium titanate substrate is removed by nitrogen blowing. Under the action of solution surface tension, the graphene and the strontium aluminate / strontium titanate substrate are bonded together.
[0043] (S4) The PMMA support layer is removed by acetone solution to realize the wet transfer of graphene from the copper substrate to the water-soluble strontium aluminate / titanate substrate.
[0044] The obtained structure is as follows Figure 3 As shown in Figure A, 20 represents graphene, 40 represents the strontium titanate substrate, and 41 represents the water-soluble strontium aluminate layer. Graphene devices fabricated on strontium aluminate / strontium titanate substrates can be completely peeled off from the substrate by dissolving the strontium aluminate in water (e.g.,...). Figure 3 As shown in B in the diagram, the electron beam can then be transferred to other substrates, for example, to overcome the problem of not being able to achieve fine patterning electron beam writing on flexible, insulating substrates, and to realize short-channel field-effect devices. In contrast, the traditional wet transfer method in aqueous solution cannot achieve this effect because the strontium aluminate layer is easily soluble in water.
[0045] Using the aqueous solution from Example 8 as an example of a van der Waals heterojunction longitudinal diode that is extremely sensitive to interfacial water and oxygen residues, the process of directly realizing a complete device through transfer is introduced:
[0046] (S1) A monolayer of molybdenum disulfide is prepared on a silicon oxide / silicon substrate by chemical vapor deposition or mechanical exfoliation, and a 50 nm platinum layer is deposited on the surface of the molybdenum disulfide as a support layer.
[0047] (S2) The silicon oxide layer is etched with potassium hydroxide solution to desorb the molybdenum disulfide and platinum support layer as a whole from the silicon oxide / silicon substrate. A special polytetrafluoroethylene carrier is used to scoop out part of the solution with floating molybdenum disulfide and platinum support layer, and place it in deionized water for 1 hour. Then, it is placed in fresh deionized water for 1 hour. This process is repeated 3 times to remove residual potassium hydroxide through liquid exchange diffusion. Using a polytetrafluoroethylene (PTFE) carrier, deionized water with a floating molybdenum disulfide and platinum support layer was scooped out and placed in phenol at 65°C to achieve water-phenol miscibility and diffusion. Then, using a specially designed PTFE carrier, a portion of the solution with the floating molybdenum disulfide and palladium support layer was scooped out again and placed in a glass bottle containing anhydrous phenol / ethanol solution at room temperature. The surface tension coefficient of phenol reaches 43.5 mN / m at room temperature, and the surface tension of its mixture with ethanol can reach 30–40 mN / m. The entire glass bottle was placed in a glove box under a nitrogen atmosphere (water and oxygen content less than 0.1 ppm) and left to stand for 2 hours. The water and oxygen circulation purification function of the glove box removed any remaining water and oxygen.
[0048] (S3) In a nitrogen atmosphere glove box, molybdenum disulfide and platinum support layer are lifted out of phenol / ethanol solution by using a silicon oxide / silicon substrate with graphene and bottom electrode on the surface (the mixed solution does not wet the surface of the treated silicon oxide / silicon substrate). The phenol / ethanol solution remaining between molybdenum disulfide and graphene on the substrate surface is removed by nitrogen blowing. Under the action of the surface tension of phenol / ethanol solution, molybdenum disulfide and graphene are bonded together.
[0049] (S4) The platinum support layer can be directly used as the electrode of molybdenum disulfide without complete removal, thereby realizing the fabrication of molybdenum disulfide / graphene van der Waals heterojunction longitudinal diode.
[0050] The obtained structure is as follows Figure 4As shown in the figure, 21 represents the platinum electrode, 20 represents molybdenum disulfide, 42 represents graphene, 41 represents the bottom electrode, and 40 represents the silicon oxide / silicon substrate. Thanks to the fact that the interface between molybdenum disulfide and graphene is completely free from water and oxygen during the bonding process, the fabricated vertical van der Waals heterojunction diode exhibits excellent heterojunction, achieving a rectification ratio on the order of 10⁴. If the substrate in step (S3) is replaced with a substrate containing easily oxidizable materials such as black phosphorus and a bottom electrode, the fabrication of a vertical van der Waals heterojunction diode can also be achieved. However, traditional methods cannot ensure that easily oxidizable materials such as black phosphorus at the interface are completely free from oxygen during the transfer process. Furthermore, this method can achieve ohmic contacts in n-type two-dimensional semiconductors: using dielectric materials such as hafnium oxide and boron nitride as supports, molybdenum ditelluride is transferred to a substrate containing easily oxidizable metal electrode materials such as titanium and aluminum, achieving ohmic contacts. In traditional wet transfer methods, the target substrate is inevitably exposed to air. Due to the rapid oxidation of the surface metal, only Schottky contacts can be obtained, and high-performance field-effect devices cannot be realized.
Claims
1. A method for anhydrous wet transfer of low-dimensional materials, characterized in that, The steps include the following: (S1) A support layer (21) is formed on the surface of a low-dimensional material (20) on a substrate (10). (S2) Separate the low-dimensional material (20) and the support layer (21) as a whole from the substrate (10), and transfer the low-dimensional material (20) and the support layer (21) as a whole into an anhydrous liquid protected by an inert gas atmosphere; (S3) Using the target substrate (40), the low-dimensional material (20) and the support layer (21) are lifted out of the anhydrous liquid as a whole. The anhydrous liquid remaining between the low-dimensional material (20) and the target substrate (40) is removed by inert gas blowing to make the low-dimensional material (20) and the target substrate (40) bond together. (S4) Remove the support layer (21) to realize the wet transfer of low-dimensional material (20) from the initial substrate (10) to the target substrate (40); The anhydrous liquid comprises 60%-100% component A and 10%-40% component B by mass percentage; component A includes one or more of glycerol, methylpyrrolidone, and quinoline; component B is anisole; the anhydrous liquid is applied in an inert atmosphere glove box to target substrates or surface films, functional microstructures, heterostructures, and bottom electrode devices that are prone to adsorbing water, dissolving in water, reacting with water, adsorbing oxygen, or being oxidized.
2. The method for anhydrous wet transfer of low-dimensional materials according to claim 1, characterized in that, The surface tension of the anhydrous liquid is adjusted by regulating the temperature.
3. The method for anhydrous wet transfer of low-dimensional materials according to claim 1, characterized in that, The wetting angle between the anhydrous liquid and the target substrate (40) to be transferred is ≥90°.
4. The method for anhydrous wet transfer of low-dimensional materials according to claim 1, characterized in that, The support layer (21) in step (S1) includes one or more combinations of metal and insulating medium.
5. The method for anhydrous wet transfer of low-dimensional materials according to claim 1, characterized in that, The inert gas atmosphere described in step (S2) includes one or more of nitrogen, argon and helium.
6. The method for anhydrous wet transfer of low-dimensional materials according to claim 1, characterized in that, Step (S3) includes immersing the target substrate (40), low-dimensional material (20) and support layer (21) into the auxiliary bonding liquid, and then removing the residual auxiliary bonding liquid after retrieval.
7. The method for anhydrous wet transfer of low-dimensional materials according to claim 6, characterized in that, The auxiliary bonding liquid includes one or more of acetone, ethanol, anisole, and toluene.
8. The method for anhydrous wet transfer of low-dimensional materials according to claim 6, characterized in that, The method for removing residual adhesive liquid is pressure expulsion.