Preparation method of thin-layer two-dimensional material island
By etching and processing the two-dimensional material samples and using the adhesive effect of the tape, the problem of uneven surface of the two-dimensional material fine sheet in the prior art is solved, and high-quality preparation of two-dimensional material fine sheets is achieved, which improves the application Value and reduce costs.
Patent Information
- Application Number
- CN202411535154.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-02-11
AI Technical Summary
It is difficult to prepare two-dimensional material fine sheets with large areas with flat surfaces and no defects in the prior art, resulting in the limitation of the actual application value of the material.
By etching the main surface of the two-dimensional material sample and using the dual viscosity of the first and second tapes, sample thin sheets with a thickness less than or equal to the thickness of the sample sheet are gradually peeled off to ensure the surface flatness between the material layers and Low friction performance.
It is easy to peel off large areas of high-quality two-dimensional material fine sheets, maintain the surface flatness and low friction properties of the material, improve the practical application value of the material, and reduce the preparation cost.
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Figure CN119409185A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present application relate to the field of two-dimensional material technology, and in particular, to a method for preparing thin-layer two-dimensional material islands. Background Art
[0002] Two-dimensional materials such as graphite and molybdenum disulfide, whose electrons can only move freely (planar motion) in two dimensions at the non-nanoscale (1-100nm), have attracted widespread attention in both basic research and applications because of their many unique physical and chemical properties, such as high conductivity, high strength, low friction coefficient and heat resistance.
[0003] Take graphite as an example. In order to obtain sufficiently thin graphite flakes, in the existing process, laser or chemical reagents are often used to directly peel off graphite flakes from graphite of a certain thickness. However, the graphite flakes peeled off in this way are far from the ideal thinness. At the same time, the surface of the graphite flakes is prone to be damaged and roughened, which greatly reduces the actual application value of the graphite flakes due to the thickness and roughness. Summary of the invention
[0004] The embodiments of the present application provide a method for preparing thin-layer two-dimensional material islands, which is used to easily peel off large-area two-dimensional material flakes with smooth surfaces and no defects, thereby improving the practical application value of the material flakes with high quality.
[0005] A first aspect of an embodiment of the present application provides a method for preparing a thin layer of two-dimensional material island, comprising:
[0006] Etching one of the main surfaces of the two-dimensional material sample so that the main surface is clean and has a concave-convex structure; the main surface is parallel to the stacking direction of each material layer in the two-dimensional material sample;
[0007] After adhering a first adhesive tape to the main surface, peeling off the first adhesive tape to cleave out a sample thin slice peeled off by the first adhesive tape; the thickness of the sample thin slice is less than the thickness of the two-dimensional material sample;
[0008] Transferring the sample slice attached with the first adhesive tape and adhering it to a second adhesive tape to cleave out sample flakes having a thickness less than or equal to the thickness of the sample slice;
[0009] The sample flakes attached to the second tape are transferred to a base sheet, and the second tape is peeled off to obtain sample flakes released onto the base sheet; wherein the surface of the base sheet is flat and clean, and the sample flakes are used to prepare at least one two-dimensional material island.
[0010] Optionally, etching one of the main surfaces of the two-dimensional material sample comprises:
[0011] The two-dimensional material sample is placed in a reactive ion etching (RIE) device to perform an etching treatment for a preset time on one of the main surfaces of the two-dimensional material sample.
[0012] Optionally, when the RIE equipment uses oxygen plasma for etching, the preset time length includes 1 to 3 minutes.
[0013] Optionally, at least one of the first tape and the second tape is a heat release tape.
[0014] Optionally, when the second adhesive tape is a thermal release adhesive tape, the process of peeling off the second adhesive tape includes:
[0015] The thermal release tape is heated so that the thermal release tape is peeled off due to reduced viscosity; the heating temperature is 100 to 200 degrees Celsius.
[0016] Optionally, the two-dimensional material sample uses highly oriented pyrolytic graphite HOPG.
[0017] Optionally, after obtaining the sample flakes released onto the substrate sheet, the method further comprises:
[0018] The sample flakes released onto the substrate are micro-processed by photoresist and mask to obtain two-dimensional material islands arranged in a desired pattern.
[0019] Optionally, the micromachining process comprises:
[0020] The sample flakes on the substrate are coated with glue, exposed and developed so that the upper surface of the sample flakes shows a desired pattern not covered by the photoresist layer;
[0021] Coating a film on the photoresist layer and the expected pattern, and using a lift-off process to peel off the photoresist layer to obtain a mask directly deposited on the upper surface and forming the expected pattern;
[0022] The sample slices are etched according to the deposition positions of the mask to obtain two-dimensional material islands arranged in the expected pattern.
[0023] Optionally, the micromachining process comprises:
[0024] Plating the sample flakes on the substrate to obtain a mask layer;
[0025] The mask layer is subjected to a process of coating, exposing and developing, so that a desired pattern covered by the photoresist layer appears above the sample slice;
[0026] According to a preset etching selectivity, the developed photoresist layer and the mask layer are dry-etched to obtain two-dimensional material islands arranged according to the expected pattern; the etching selectivity refers to the etching rate ratio between the photoresist exposed above the sample slice and the coating material under the same etching conditions.
[0027] Optionally, the thickness of the two-dimensional material sample is greater than 200 microns; the thickness of the sample slice is between 5 microns and 100 microns; the thickness of the sample flake is between 100 nanometers and 10 microns.
[0028] It can be seen from the above technical solutions that the embodiments of the present application have at least the following advantages:
[0029] The embodiment of the present application performs etching treatment on the main surface of the two-dimensional material sample, which can enhance the adsorption force between the two-dimensional material sample and the first tape, so that at least the material layer on the main surface can be peeled off by the first tape, thereby easily obtaining a thinned sample slice. In addition, the effective adsorption of the sample slice by the second tape can be combined with the viscosity of the first tape to help the sample slice to be peeled off from the middle layer area through the dual effects of the upper and lower layers, so that the sample flakes left after further peeling can well maintain the original surface flatness and low friction performance between the material layers, that is, the material cross-section produced by peeling is complete and smooth, avoiding material fragmentation and surface roughness that affect its actual application value; at the same time, it helps to reduce the preparation cost of the two-dimensional material island. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.
[0031] It should be noted that, although the steps in the process diagrams (if any) involved in the embodiments are drawn in sequence as indicated by the arrows, unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a portion of the steps or stages in other steps.
[0032] Figure 1 A schematic diagram of a process for preparing a thin layer of two-dimensional material island according to an embodiment of the present application;
[0033] Figure 2 Schematic diagram of the wet etching process of a thin layer of two-dimensional material island in an embodiment of the present application;
[0034] Figure 3 Schematic diagram of the dry etching process of the thin layer two-dimensional material island in the embodiment of the present application. DETAILED DESCRIPTION
[0035] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. The described embodiments should not be regarded as limiting the present application. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.
[0036] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims and drawings of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0037] In the following description, similar expressions such as "a specific implementation" or "a specific example" are involved, which describe a subset of all possible embodiments, but it can be understood that "a specific implementation" or "a specific example" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict. In the following description, the term multiple refers to at least two. In some specific examples, the numerical value mentioned in this application reaches the threshold value (if any), which may include the case where the former is greater than the latter of the threshold value; if similar expressions such as "any" or "at least one" are mentioned, it can specifically refer to any one of the listed examples or any combination of these examples.
[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.
[0039] The method of the present application will be described in further detail below.
[0040] See also Figure 1In a first aspect, the present application provides a specific embodiment of a method for preparing a thin layer of two-dimensional material island, which comprises the following steps:
[0041] Step S11, etching one of the main surfaces of the two-dimensional material sample so that the main surface is clean and has a concave-convex structure;
[0042] In practical applications, the above-mentioned two-dimensional material samples can specifically be two-dimensional materials such as graphite or molybdenum disulfide. For the convenience of explanation and understanding, the embodiments of the present application mainly use highly oriented pyrolytic graphite (HOPG) as a two-dimensional material sample for illustrative explanation. Therefore, the method for preparing thin-layer two-dimensional material islands in the embodiments of the present application can be further referred to as a method for cleaving ultra-thin HOPG and preparing graphite islands.
[0043] For example, one of the main surfaces of a complete HOPG sample with a size of 1.2mm*1.2mm*(thickness)1mm can be etched to make the main surface clean and have a concave-convex structure. In other words, the etching process can form a clean and pollution-free microporous rough surface on the main surface of the HOPG sample. The above-mentioned main surface is parallel to the stacking direction of each material layer in the two-dimensional material sample. For example, the HOPG sample is generally stacked up flat by each layer of graphite layers, so the exposed surface of the uppermost and lowermost graphite layers can be called the main surface of the HOPG sample. For ease of explanation, the embodiment of the present application mainly uses the exposed surface of the uppermost graphite layer as the main surface to be etched.
[0044] Compared with the smooth surface, the above-mentioned concave-convex structure can utilize the micropore gaps to enhance the adhesion between the tape and the graphite layer, making it easier to peel off the flat sample slices from between the layers through the adhesion of the tape.
[0045] Step S12, after adhering the first adhesive tape to the main surface, peeling off the first adhesive tape to cleave out the sample slice peeled off by the first adhesive tape;
[0046] A polymer fiber tape (such as 3M brand tape) can be selected as the first tape and adhered to the main surface with a concave-convex structure. By pressing and then peeling off the first tape, the sample slice peeled off by the first tape can be cleaved out; the thickness of the sample slice is smaller than the thickness of the two-dimensional material sample. After many experiments, it is concluded that the thickness of the sample slice at this time can be between a few microns and tens of microns.
[0047] As explained above, due to the presence of the concave-convex structure, the stickiness of the tape allows the graphite layer on the bonding surface to be peeled off along with the tape, which is equivalent to causing interlayer separation inside the HOPG sample. The peeled-off thin slice section can still maintain the original flatness and integrity between the layers, that is, the graphite layer is torn off in one piece without any defects.
[0048] Step S13, transferring the sample slice attached with the first adhesive tape and adhering it to the second adhesive tape, so as to cleave out sample flakes having a thickness less than or equal to the thickness of the sample slice;
[0049] The first tape and the second tape can be of the same or different types. For example, at least one of the first tape and the second tape is a thermal release tape. After being heated, the thermal release tape will be easily separated from the adhesive due to reduced viscosity. For ease of description and understanding, the embodiments of this application are mainly described by exemplifying 3M brand tape as the first tape and thermal release tape as the second tape. Of course, other tapes can be used as substitutes in actual situations.
[0050] Specifically, a second tape can be adhered to the other main surface of the sample slice that is not adhered to the first tape, so that the upper and lower surfaces of the sample slice are adhered with tape. By virtue of the relative force between the upper and lower surfaces, by peeling off the first tape, a further thinned sample slice can be obtained attached to the second tape. At this time, it can be considered that the required ultra-thin layer of HOPG has been obtained, and the thickness of this sample slice can be reduced to between several hundred nanometers and several microns.
[0051] In some specific examples, the above steps S12 and / or S13 may be repeated at least once, that is, the two-dimensional material may be repeatedly cleaved by the first tape and / or the second tape multiple times, so that the thickness of the two-dimensional material is gradually reduced to the desired thickness.
[0052] Step S14, transferring the sample flakes attached to the second adhesive tape to the base sheet, and peeling off the second adhesive tape to obtain the sample flakes released onto the base sheet.
[0053] The above-mentioned substrate sheet can be a substrate such as a silicon (Si) sheet, a sapphire sheet or a glass sheet. This substrate generally requires a flat and clean surface and can have good van der Waals force with the two-dimensional material. Taking the Si sheet as an example, the ultra-thin layer of HOPG on the second tape (such as a thermal release tape) can be transferred to the Si sheet, and the thermal release tape is heated to reduce the viscosity of the thermal release tape to obtain an ultra-thin layer of HOPG released to the substrate sheet. The ultra-thin layer of HOPG cleaved and transferred to the substrate sheet in this way can be used to prepare at least one two-dimensional material island. The specific preparation process of this two-dimensional material island can be seen below.
[0054] In summary, the embodiment of the present application performs etching treatment on the main surface of the two-dimensional material sample, which can enhance the adsorption force between the two-dimensional material sample and the first tape, so that at least the material layer on the main surface can be peeled off by the first tape, thereby easily obtaining a thinned sample slice. In addition, the effective adsorption of the sample slice by the second tape can be combined with the viscosity of the first tape to help the sample slice to be peeled off from the middle layer area through the dual effects of the upper and lower layers, so that the sample flakes left after further peeling can well maintain the original surface flatness and low friction performance between the material layers, that is, the material cross-section produced by peeling is complete and smooth, avoiding material fragmentation and surface roughness that affect its actual application value; at the same time, it helps to reduce the preparation cost of the two-dimensional material island.
[0055] Based on the above example descriptions, some specific possible implementation examples will be provided below. In actual applications, the implementation contents between these examples can be combined or implemented separately as needed according to the corresponding functional principles and application logic. If implemented in combination, the execution order between the combined examples can be determined according to their respective processing logics, which can be determined by the actual scenario.
[0056] See also Figure 2 In some specific examples, the specific operation process of step S11 may include: placing the two-dimensional material sample into an etching device to perform an etching treatment for a preset time on one main surface of the two-dimensional material sample.
[0057] The etching equipment can be one of reactive ion etching (RIE) equipment, chemical mechanical polishing (CMP) equipment, laser etching equipment, and electron beam etching equipment. Among them, chemical mechanical polishing (CMP) equipment: although CMP is mainly used to flatten the surface, in some cases, it can also be regarded as an "etching" technology because it removes specific parts of the material surface through the combined action of chemistry and mechanics; laser etching equipment: using the high energy density and precise controllability of the laser beam to locally heat and evaporate the material, thereby achieving high-precision etching; electron beam etching equipment: similar to laser etching, but using electron beam as the etching source, with higher resolution and smaller feature size.
[0058] In some specific examples, if the above-mentioned etching equipment is a RIE equipment, and the RIE equipment uses oxygen plasma (O2plasma) for etching, the preset etching time includes 1 to 3 minutes, so that the main surface of the HOPG sample can be bombarded with a concave-convex structure, that is, the surface of the HOPG is roughened. Of course, in actual situations, the preset etching time can be determined comprehensively according to the specific material of the sample (such as graphite or molybdenum disulfide), the actual thickness of the surface layer, the gas type (oxygen or argon) to which the plasma belongs, etc., which is only an example here and is not specifically limited.
[0059] In some specific examples, when the second tape is a heat release tape, the process of peeling off the second tape in step S14 includes: heating the heat release tape serving as the second tape so that the heat release tape is peeled off due to reduced viscosity; the heating temperature can be 100 to 200 degrees Celsius, specifically 150 degrees Celsius; the heating time can be determined according to actual conditions, generally as long as the viscosity of the second tape can be reduced or lost, it is convenient to peel off the second tape.
[0060] In some specific examples, after step S14, the method of the embodiment of the present application may further include (preparing two-dimensional material islands): micro-processing the sample slices released onto the substrate sheet through photoresist and mask to obtain two-dimensional material islands arranged in a desired pattern.
[0061] In practical applications, the etching process in this micro-machining process can be implemented in different ways such as wet etching or dry etching. The wet etching process can refer to a lift-off process, which mainly uses the chemical reaction of the solution to strip (or etch) the photoresist layer; while the dry etching process refers to a waterless stripping process that does not use a solution to strip the photoresist layer. In addition, what is different is that for the coating process (such as metal film) in micro-machining, the coating process is executed after the glue coating when the lift-off process is used, and before the glue coating when the dry etching process is used; for this reason, the same HOPG sample is processed through the lift-off process or the dry etching process, and the position and size of the graphite islands finally formed on the substrate are different relative to the HOPG sample as a whole. For details, please see the following text description, Figure 2 , Figure 3 .
[0062] 1. Lift-off process is used to remove the photoresist layer in micromachining
[0063] As a possible implementation mode, the above-mentioned micro-machining process may specifically include: coating, exposing and developing the sample flakes on the substrate so that the upper surface of the sample flakes shows the expected pattern not covered by the photoresist layer; coating the photoresist layer and the expected pattern, and using a lift-off process to peel off the photoresist layer to obtain a mask directly deposited on the upper surface and forming the expected pattern; etching the sample flakes according to the deposition position of the mask to obtain two-dimensional material islands arranged in the expected pattern.
[0064] Specifically, Figure 2As shown, the HOPG flakes on the silicon wafer can be coated with glue (such as photoresist), exposed, and developed to obtain a photoresist pattern not covered by the photoresist layer; then, a metal film can be plated on the surface of the photoresist layer and the upper surface of the exposed HOPG flakes through electron beam evaporation or magnetron sputtering, and then the unnecessary photoresist can be dissolved away using a remover of the lift-off process to retain the required metal pattern mask; finally, the HOPG flakes can be etched using oxygen plasma with reference to the distribution position of the metal pattern mask to form pieces of graphite islands.
[0065] 2. Dry etching process is used to strip the photoresist layer in micromachining
[0066] As another possible implementation, the above-mentioned micro-machining process may specifically include: coating the sample flakes on the substrate to obtain a mask layer; coating, exposing and developing the mask layer so that the expected pattern covered by the photoresist layer appears above the sample flakes; dry etching the developed photoresist layer and the mask layer according to a preset etching selectivity to obtain two-dimensional material islands arranged according to the expected pattern; the etching selectivity refers to the etching rate ratio between the photoresist exposed above the sample flakes and the coating material under the same etching conditions.
[0067] Specifically, Figure 3 As shown, the HOPG flakes attached to the substrate can be coated (such as (metal film or other dielectric film), and the coating process can be specifically electron beam evaporation or magnetron sputtering process; then, the HOPG flakes can be coated, exposed, and developed to design the expected pattern covered by the photoresist layer, that is, surface patterning design is performed; using gas plasma such as oxygen or argon, the developed HOPG flakes are dry-etched to dissolve the top layer of material (because etching is from top to bottom), such as dissolving all the photoresist and the exposed part of the metal film on the top, and retaining the metal film originally covered and protected by the photoresist. Of course, in order to achieve such an ideal product effect with both deletion and retention, it is necessary to control the etching selectivity between the photoresist and the metal film, which is crucial for accurately controlling the size and shape of the graphite island forming pattern; the remaining metal film can be used as the graphite island cover, and finally, the metal island cover mask can be etched away to complete the preparation of the graphite island.
[0068] Exemplarily, the calculation formula of the above etching selectivity ratio can be recorded as: etching selectivity ratio = etching rate of masking layer material (such as photoresist) / etching rate of etched material (such as metal), such as Figure 3As shown, selecting a low selectivity (i.e., the denominator is greater than the numerator) here means that during the etching process, the photoresist on the metal film is as small as possible, and the metal layer that is not covered and protected by the photoresist (i.e., exposed) is etched away as much as possible. Because etching is generally from top to bottom, the selectivity is small or even non-existent, so the etching selectivity in this formula can be between 1:5 and 1:10. Of course, in practical applications, the value of the above etching selectivity can be comprehensively determined according to the thickness, distribution size, etc. of the covered photoresist and metal film, and is not specifically limited.
[0069] It should be noted that, in some specific examples, the thickness of the above-mentioned two-dimensional material sample can be more than 200 microns; the thickness of the sample slice prepared by the above method of the embodiment of the present application can be between 5 microns and 100 microns, and the thickness of the sample thin slice can be between 100 nanometers and 10 microns.
[0070] In summary, the embodiment of the present application can use 3M tape and thermal release tape to perform ultra-thin layer cleavage of HOPG and transfer it to a silicon wafer to prepare graphite islands. The flat area and friction performance of the cleaved HOPG flakes are highly similar to those of the original whole piece of HOPG, so that the utilization rate of HOPG is improved by an order of magnitude, greatly reducing the material cost. The above method of the embodiment of the present application has good repeatability and simple operation. It is one of the important paths to the low-cost batch preparation of super-sliding blocks. It can be used for mass production of super-slip product projects, so that the product cost can be reduced by dozens of times compared with the previous technical path.
[0071] Compared to Figure 1 The examples shown illustrate that the above-mentioned additional or detailed example contents or possible implementation methods do not necessarily have to be executed during the specific implementation. If more than two examples or possible implementation methods are added, these examples or possible implementation methods can be implemented in combination or separately. If implemented in combination, the execution order between the combined examples can be determined according to their respective processing logic, which can be determined according to the actual scenario.
[0072] The above embodiments are only used to illustrate the technical solution of the present application, but not to limit it.
Claims
1. A method for preparing a thin layer of two-dimensional material island, characterized in that: include: Performing an etching process on one of the main surfaces of the two-dimensional material sample so that the main surface is clean and has a concave-convex structure; The main surface is parallel to the stacking direction of each material layer in the two-dimensional material sample; After adhering a first adhesive tape to the main surface, peeling off the first adhesive tape to cleave out a sample thin slice peeled off by the first adhesive tape; the thickness of the sample thin slice is less than the thickness of the two-dimensional material sample; Transferring the sample slice attached with the first adhesive tape and adhering it to a second adhesive tape to cleave out sample flakes having a thickness less than or equal to the thickness of the sample slice; The sample flakes attached to the second tape are transferred to a base sheet, and the second tape is peeled off to obtain sample flakes released onto the base sheet; wherein the surface of the base sheet is flat and clean, and the sample flakes are used to prepare at least one two-dimensional material island.
2. The method for preparing a thin layer of two-dimensional material island according to claim 1, characterized in that: The etching process on one of the main surfaces of the two-dimensional material sample comprises: The two-dimensional material sample is placed in a reactive ion etching (RIE) device to perform an etching treatment for a preset time on one of the main surfaces of the two-dimensional material sample.
3. The method for preparing a thin layer of two-dimensional material island according to claim 2, characterized in that: When the RIE equipment uses oxygen plasma for etching, the preset duration ranges from 1 to 3 minutes.
4. The method for preparing a thin layer of two-dimensional material island according to claim 1, characterized in that: At least one of the first tape and the second tape is a heat release tape.
5. The method for preparing a thin layer of two-dimensional material island according to claim 1, characterized in that: When the second adhesive tape is a thermal release adhesive tape, the process of peeling off the second adhesive tape includes: The thermal release tape is heated so that the thermal release tape is peeled off due to reduced viscosity; the heating temperature is 100 to 200 degrees Celsius.
6. The method for preparing a thin layer of two-dimensional material island according to claim 1, characterized in that: The two-dimensional material sample adopts highly oriented pyrolytic graphite HOPG.
7. The method for preparing a thin layer of two-dimensional material island according to any one of claims 1 to 6, characterized in that: After obtaining the sample flakes released onto the substrate sheet, the method further comprises: The sample flakes released onto the substrate are micro-processed by photoresist and mask to obtain two-dimensional material islands arranged in a desired pattern.
8. The method for preparing a thin layer of two-dimensional material island according to claim 7, characterized in that: The micromachining process includes: The sample flakes on the substrate are coated with glue, exposed and developed so that the upper surface of the sample flakes shows a desired pattern not covered by the photoresist layer; Coating a film on the photoresist layer and the expected pattern, and using a lift-off process to peel off the photoresist layer to obtain a mask directly deposited on the upper surface and forming the expected pattern; The sample slices are etched according to the deposition positions of the mask to obtain two-dimensional material islands arranged in the expected pattern.
9. The method for preparing a thin layer of two-dimensional material island according to claim 7, characterized in that: The micromachining process includes: Plating the sample flakes on the substrate to obtain a mask layer; The mask layer is subjected to a process of coating, exposing and developing, so that a desired pattern covered by the photoresist layer appears above the sample slice; According to a preset etching selectivity, the developed photoresist layer and the mask layer are dry-etched to obtain two-dimensional material islands arranged according to the expected pattern; the etching selectivity refers to the etching rate ratio between the photoresist exposed above the sample slice and the coating material under the same etching conditions.
10. The method for preparing a thin layer of two-dimensional material island according to any one of claims 1 to 6, characterized in that: The thickness of the two-dimensional material sample is more than 200 microns; the thickness of the sample slice is between 5 microns and 100 microns; the thickness of the sample flake is between 100 nanometers and 10 microns.