阅读说明：本技术 一种大尺度超滑器件的制备方法 (Preparation method of large-scale ultra-smooth device ) 是由 郑泉水 邓杨 于 2020-05-29 设计创作，主要内容包括：本发明涉及一种大尺度超滑器件的制备方法,包括提供具有原子级光滑平整的表面的第一基底；提供第二基底,利用化学气相沉积技术在第二基底上生长大尺度石墨烯薄膜,并将该大尺度石墨烯薄膜转移至第一基底原子级光滑平整的表面上；利用压力使该大尺度石墨烯薄膜与第一基底原子级平整的表面紧密贴合,由此制备得到大尺度超滑器件。该方法具有工艺简单、经济高效以及可重复性好等优点,利用该方法制备出的大尺度超滑器件具有大面积、摩擦系数低以及耐磨性好等优点,能够解决目前结构超滑仅限于微纳尺度难以在实际机械运动部件上应用的问题,具有巨大的工程应用价值。(The invention relates to a preparation method of a large-scale ultra-smooth device, which comprises the steps of providing a first substrate with an atomic-scale smooth and flat surface; providing a second substrate, growing a large-scale graphene film on the second substrate by using a chemical vapor deposition technology, and transferring the large-scale graphene film onto the atomic-level smooth and flat surface of the first substrate; and (3) tightly attaching the large-scale graphene film to the atomically flat surface of the first substrate by using pressure, thereby preparing the large-scale ultra-smooth device. The method has the advantages of simple process, economy, high efficiency, good repeatability and the like, the large-scale super-slip device prepared by the method has the advantages of large area, low friction coefficient, good wear resistance and the like, can solve the problem that the current structure super-slip is limited to micro-nano scale and is difficult to apply to actual mechanical moving parts, and has great engineering application value.)

1. A method of fabricating a large-scale ultra-smooth device, comprising:

step 1: providing a first substrate having an atomically flat surface;

step 2: providing a second substrate, and growing a multilayer two-dimensional material film on the second substrate, wherein the multilayer two-dimensional material film is provided with a first surface and a second surface;

and step 3: transferring the multilayer two-dimensional material thin film onto an atomically flat surface of the first substrate;

and 4, step 4: carrying out drying treatment on the first substrate with the multilayer two-dimensional material film;

the method is characterized in that:

further comprising the step 5: and tightly covering the first surface of the multilayer two-dimensional material film on the atomically flat surface of the first substrate by applying tension and/or pressure to the multilayer two-dimensional material film, so that the second surface of the multilayer two-dimensional material film is a super-smooth surface.

2. The method of fabricating a large-scale ultra-smooth device according to claim 1, wherein: the size of the first substrate is 10-500 um; the first substrate material is silicon, germanium, boron nitride, quartz, heat-resistant glass, GaAs, AlTiC, Si3N4, metal, polymer and other materials, and the first substrate material is preferably silicon, and more preferably a monocrystalline silicon wafer.

3. The method of fabricating a large-scale ultra-smooth device according to claim 1, wherein: the whole surface of the first substrate is an atomic-level flat surface; or the surface of the first substrate is provided with bulges arranged in a certain shape, the bulges are provided with atomically flat surfaces, and the shape is a circle, a polygon or an irregular shape, preferably a polygon shape such as a square, a rectangle, a hexagon and the like, and more preferably a hexagon.

4. A method of fabricating a large scale ultra-smooth device as claimed in claim 3, characterized in that: the bulges are cylinders or polygonal cylinders, preferably cylinders; the convex cross sectional area is 1-50um, the convex height is 10nm-10um, and the distance between adjacent bulges is less than 1-10 um.

5. The method of fabricating a large-scale ultra-smooth device according to claim 1, wherein: growing a large-scale multilayer two-dimensional material film on the second substrate by a chemical vapor deposition method, preferably, the multilayer two-dimensional material film is a multilayer graphene film, the second substrate material is copper or nickel or an alloy thereof, the size of the second substrate is 10-500um, and preferably, the step 2 further comprises forming a protective layer on the multilayer two-dimensional material film; the protective layer includes at least one material selected from the group consisting of a high molecular polymer, a Photoresist (PR), an Electron Resist (ER), silicon oxide (SiOx), and aluminum oxide (AlOx) formed by spin coating; the high molecular polymer is selected from one or more of polymethyl methacrylate (PMMA), polycarbonate, polystyrene, polyethylene and polypropylene.

6. The method of fabricating a large-scale ultra-smooth device according to claim 1, wherein: the transfer process of the step 3 comprises the following steps:

putting the second substrate with the multilayer two-dimensional material film into a solution to etch the second substrate;

putting the first substrate into a solution, depositing the first surface of the multilayer two-dimensional material film on the surface of the first substrate, and fishing out the multilayer two-dimensional material film from the solution by using the first substrate;

preferably, the solution is selected from the group consisting of acid solutions, hydrogen fluoride solutions, buffered oxide etching solutions, FeCl₃Solution and Fe (NO)₃)₃At least one of the group consisting of solutions; more preferably, the solution is an acid solution comprising sulfuric acid, hydrochloric acid, nitric acid, n-butanol, and acetic acidOne or more of phosphoric acid and acetic acid.

7. The method of fabricating a large-scale ultra-smooth device according to claim 1, wherein: the pulling force in the step 5 is applied to the first substrate and the multilayer two-dimensional material film through a suction force generated by a capillary force, and the pressure is applied through compressed air.

8. The method of fabricating a large-scale ultra-smooth device according to claim 7, wherein: the applying pressure comprises the steps of:

applying a pressure of 10-150MPa and maintaining for 10-30min to enable the first surface of the multilayer two-dimensional material film to closely cover the surface of the first substrate, wherein after the first surface of the multilayer two-dimensional material film is closely attached to the surface of the first substrate, the second surface of the multilayer two-dimensional material film presents an atomically flat surface, and the second surface of the multilayer two-dimensional material film presents a super-smooth surface, so that a large-scale super-smooth device is prepared, preferably, the multilayer two-dimensional material film is a graphene film.

9. The method of fabricating a large-scale ultra-smooth device according to claim 1, wherein: the method further comprises a detection step, wherein the detection step is used for detecting whether the second surface of the multilayer two-dimensional material film is a super-smooth surface.

10. A large-scale ultra-slip device obtained by the method of manufacturing a large-scale ultra-slip device according to any one of claims 1 to 9.

Technical Field

The invention relates to the field of solid structure ultra-smoothness, in particular to a preparation method of a large-scale ultra-smooth device.

Background

For mechanically moving parts, friction and wear are the main forms of energy dissipation, which also results in unnecessary loss of material. For a long time, friction and wear problems, not only closely related to manufacturing, but also directly related to energy, environment and health, have shown that nearly 1/3 disposable energy sources are used to overcome friction and more than 50% of the vicious incidents of mechanical equipment result from lubrication failure and excessive wear. Reducing the frictional wear of mechanical moving parts is regarded as one of the ways to effectively improve the reliability and stability of the operation of a mechanical system and prolong the working life of the mechanical system, while the lubricating material technology is the most effective means for reducing the friction, reducing or avoiding the wear, prolonging the service life of equipment and improving the working efficiency, so that designing a mechanical system with ultra-low friction coefficient and wear and establishing an ultra-smooth system have great economic and social significance for saving energy to the maximum extent and reducing the emission of harmful substances in the mechanical system to the atmospheric environment. For a contact interface with relative motion under the actual working condition, structural ultra-smoothness is one of ideal schemes for solving the problems of energy dissipation and mechanical damage caused by frictional wear, and the structural ultra-smoothness is a phenomenon that the friction and the wear between two atomic-level smooth and non-metric contact Van der Waals solid surfaces are almost zero. In 2004, the netherlands scientist j.frenken's research group measured the friction of a few nm-sized (total of about 100 carbon atoms) graphite sheet stuck on a probe when the crystal face of Highly Oriented Pyrolytic Graphite (HOPG) slides by experimental design, and the first experiment confirmed the existence of nano-scale super lubrication. Later, the ultra-smooth structure draws wide attention of people and makes good progress, in 2012, Liu and Zheng spring water and the like firstly realize the ultra-smooth structure with micron scale, and the experiment of designing the self-retraction motion of the graphite island by utilizing HOPG proves that the friction force in the micron-scale graphite island obviously has the basic characteristic of the ultra-smooth structure. At present, the ultra-smooth structure is mainly focused on micro-nano scale, and is difficult to be applied to actual mechanical moving parts, and the ultra-smooth structure has engineering application value, and the ultra-smooth structure with large scale must be realized, namely, the ultra-smooth device with large scale must be prepared, so how to prepare the ultra-smooth device with large scale to realize the ultra-smooth structure with large scale and further realize the surface macro ultra-smooth is a difficult problem to be solved by researchers in the fields of international tribology, advanced manufacturing, energy, physics, chemistry, materials and the like.

The ultra-smooth material with potential application value can be graphene, molybdenum disulfide or other two-dimensional materials. Preferably, the graphene is a novel two-dimensional carbon material, has excellent mechanical properties, lubricating properties and structural stability, and has the characteristic of the same friction coefficient under dry and wet conditions, which is extremely rare, so that the graphene is a macroscopic super-smooth material with great potential application value. Conventional graphene preparation methods developed at present include: micro-mechanical lift-off, pyrolytic silicon carbide (SiC), Chemical Vapor Deposition (CVD) on transition metals and heavy metals, and chemical intercalation oxidation. The Chemical Vapor Deposition (CVD) method has the characteristics of simplicity, easiness in operation, high quality of prepared graphene and large size (centimeter magnitude), and is suitable for preparing large-scale graphene. In the prior art, researches on preparation of large-scale graphene mainly focus on the conductivity of graphene, and researches on how to prepare large-scale graphene to enable the large-scale graphene to have super-slip performance are not reported.

Disclosure of Invention

The invention aims to provide a method for preparing a large-scale ultra-smooth device, in particular to a method for preparing large-scale graphene, and the large-scale graphene prepared by the method has ultra-smooth performance.

The purpose of the invention is realized by the following technical scheme:

a method of fabricating a large-scale ultra-smooth device, comprising:

step 1: providing a first substrate having an atomically flat surface;

step 2: providing a second substrate, and growing a multilayer two-dimensional material film on the second substrate, wherein the multilayer two-dimensional material film is provided with a first surface and a second surface;

and step 3: transferring the multilayer two-dimensional material thin film onto an atomically flat surface of the first substrate;

and 4, step 4: carrying out drying treatment on the first substrate with the multilayer two-dimensional material film;

and 5: and tightly covering the first surface of the multilayer two-dimensional material film on the atomically flat surface of the first substrate by applying tension and/or pressure to the multilayer two-dimensional material film, so that the second surface of the multilayer two-dimensional material film is a super-smooth surface.

According to an aspect of the present invention, the first base material may be silicon, germanium, boron nitride, quartz, pyrex, GaAs, AlTiC, Si3N4, metal, polymer, or the like, and the first base material is preferably silicon, and more preferably a single crystal silicon wafer.

According to another aspect of the invention, the first substrate has a size of 10-500 um.

According to another aspect of the invention, the surface of the first substrate is entirely an atomically flat surface.

According to another aspect of the invention, the surface of the first substrate is micro-machined with shaped protrusions having atomically flat surfaces prepared by micro-machining techniques. The shape may be circular, polygonal or irregular, preferably polygonal such as square, rectangular or hexagonal, more preferably hexagonal.

According to another aspect of the invention, the protrusions may be cylindrical or polygonal cylinders, preferably cylindrical.

According to another aspect of the present invention, the cross-sectional area of the protrusions is 1-50um, the height of the protrusions is 10nm-10um, and the interval between adjacent protrusions is 1-10 um.

According to another aspect of the invention, the second substrate material may be copper or nickel, or an alloy thereof.

According to another aspect of the invention, the second substrate has a size of 10-500 um.

According to another aspect of the invention, the step 3 transferring process comprises:

putting the second substrate with the multilayer two-dimensional material film into a solution to etch the second substrate;

putting the first substrate into a solution, depositing the first surface of the multilayer two-dimensional material film on the surface of the first substrate, and fishing out the multilayer two-dimensional material film from the solution by using the first substrate;

according to another aspect of the invention, the solution is selected from the group consisting of acid solutions, hydrogen fluoride solutions, buffered oxide etch solutions, FeCl₃Solution and Fe (NO)₃)₃At least one of the group consisting of solutions; preferably, the acid solution comprises one or more of sulfuric acid, hydrochloric acid, nitric acid, orthophosphoric acid and acetic acid.

According to another aspect of the present invention, the step 2 further comprises: and forming a protective layer on the large-scale graphene film to prevent the large-scale graphene film from being damaged in the subsequent treatment process. The protective layer may include at least one material selected from the group consisting of a high molecular polymer, a Photoresist (PR), an Electron Resist (ER), silicon oxide (SiOx), and aluminum oxide (AlOx) formed by spin coating; the high molecular polymer is selected from one or more of polymethyl methacrylate (PMMA), polycarbonate, polystyrene, polyethylene and polypropylene.

According to another aspect of the present invention, the number of graphene thin films is 1 to 10, the number of layers depends on the amount of carbon source supplied, and the size depends on the size of the second substrate used in the preparation process.

According to another aspect of the invention, the carbon source may be a gaseous carbon source, a liquid carbon source or a solid carbon source.

According to another aspect of the present invention, the step 4 further comprises: and dissolving and removing the protective layer covering the surface of the large-scale graphene film by using an organic solvent, wherein the organic solvent can be an acetone solution.

According to another aspect of the invention, the drying treatment comprises drying with a vacuum drying oven, inclined standing for natural airing or heat drying.

According to another aspect of the present invention, the pulling force in step 5 is applied to the first substrate and the multilayer two-dimensional material film by a suction force generated by a capillary force, and the pressure is applied by compressed air.

According to another aspect of the invention, said applying pressure comprises the steps of:

applying a pressure of 10-150MPa and maintaining for 10-30min to enable the first surface of the multilayer two-dimensional material film to closely cover the surface of the first substrate, wherein after the first surface of the multilayer two-dimensional material film is closely attached to the surface of the first substrate, the second surface of the multilayer two-dimensional material film presents an atomically flat surface, and the second surface of the multilayer two-dimensional material film presents a super-smooth surface, so that a large-scale super-smooth device is prepared, preferably, the multilayer two-dimensional material film is a graphene film.

According to another aspect of the invention, after the preparation of the large-scale ultra-smooth device is completed, the method further comprises a detection step, wherein the detection step is used for detecting whether the second surface of the large-scale graphene film is an ultra-smooth surface.

The invention has the following beneficial effects:

the invention provides a first substrate and a second substrate, a large-scale graphene film grows on the second substrate by utilizing a chemical vapor deposition technology, the large-scale graphene film is transferred onto the atomically flat surface of the first substrate, and then the large-scale graphene film is tightly attached to the atomically flat surface of the first substrate by utilizing pressure, so that a large-scale ultra-smooth device is prepared. The invention has the advantages of simple process, economy, high efficiency, good repeatability and the like, the large-scale super-slip device prepared by the invention has the advantages of large area, low friction coefficient, good wear resistance and the like, can solve the problem that the current structure super-slip is only limited to micro-nano scale and is difficult to apply to actual mechanical moving parts, and has great engineering application value.

Drawings

FIG. 1 is a general flow chart of a method for fabricating a large-scale ultra-smooth device according to an embodiment.

FIG. 2 is a schematic diagram of a first substrate according to an embodiment.

FIG. 3 is a schematic view of a first substrate with a cylinder according to another embodiment

Fig. 4 is a schematic diagram of a method for manufacturing a large-scale ultra-smooth device according to an embodiment, each step showing a related structure of a large-scale graphene, a first substrate and a second substrate.

Fig. 5 shows an embodiment in which a large-scale graphene film is tightly attached to a first substrate by air pressure.

Reference numerals:

the graphene substrate comprises a first substrate 10, a first substrate surface 101, a first substrate ' 10 ', a first substrate surface ' 101 ', a first substrate upper cylinder 102 ', a second substrate 20, a large-size graphene film 30, a first surface 301 and a second surface 302.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Referring to fig. 1, an embodiment of the present invention provides a flow chart for manufacturing a large-scale ultra-smooth device, including the following steps:

s1: providing a first substrate having an atomically flat surface prepared by micromachining techniques;

s2: providing a second substrate, and growing a large-scale graphene film on the second substrate by a Chemical Vapor Deposition (CVD) technology, wherein the large-scale graphene film is provided with a first surface and a second surface;

s3: placing the second substrate with the large-scale graphene thin film into a solution to etch the second substrate;

s4: putting the first substrate into a solution, then sinking the first surface of the large-scale graphene film on the surface of the first substrate, and fishing out the large-scale graphene film from the solution by using the first substrate;

s5: drying the first substrate with the large-scale graphene film;

s6: and after the first surface of the large-scale graphene film is tightly covered on the surface of the first substrate by using pressure, because the surface of the first substrate is an atomically flat surface after the first surface of the large-scale graphene film is tightly attached to the surface of the first substrate, the first surface of the large-scale graphene film is an atomically flat surface, the second surface of the large-scale graphene film is also an atomically flat surface, and the second surface of the large-scale graphene film is a super-slip surface, so that the large-scale super-slip device is prepared.

There is provided a first substrate 10 of an embodiment, the first substrate 10 having an atomically flat surface 101 prepared by a micro-machining technique, the first substrate having a size of 50 um; selecting a copper foil with the size of 50um as a second substrate; growing a large-scale graphene film 30 on the surface of the second substrate by adopting a CVD method, wherein a carbon source is methane, gas is mixed gas of H2 and He, the deposition temperature is 580 ℃ and 650 ℃, and the deposition pressure is 1 x 10 in the process of depositing the graphene film by adopting the CVD method^-4～6*10^{- 4}Pa. The large-scale graphene thin film 30 has a first surface 301 and a second surface 302; the second substrate 2 with the large-scale graphene thin film 30 is placed0 into a solution to etch the second substrate 20; putting the first substrate 10 into a solution, then sinking the first surface 301 of the large-scale graphene thin film 30 on the surface 101 of the first substrate 10, and fishing out the large-scale graphene thin film 30 from the solution by using the first substrate 10; and drying to obtain the first substrate 10 with the large-scale graphene film 30. The method comprises the steps of placing a first substrate 10 with a large-size graphene film in a container, connecting the container with a compression pump, realizing a continuous pressurization process under the action of the compression pump, controlling the pressurization time to be 15min, controlling the air pressure to be 50Mpa, enabling the first surface of the large-size graphene film to be tightly covered on the surface of the first substrate by utilizing the air pressure, and enabling the graphene film 30 to generate in-plane stretching by utilizing or simultaneously combining a suction force generated by a capillary force, so that the first surface of the large-size graphene film is tightly covered on the surface of the first substrate, and obtaining an ultra-smooth surface. Placing the large-size ultra-smooth device on a flat substrate plane of 10cm for a sliding friction experiment, wherein the friction coefficient is 3 x 10^-4The abrasion is almost 0, and the requirement of ultra-smoothness is met.

According to yet another embodiment of the invention, the solution is selected from the group consisting of acid solutions, hydrogen fluoride solutions, buffered oxide etch solutions, FeCl₃Solution and Fe (NO)₃)₃At least one of the group consisting of solutions; preferably, the acid solution comprises one or more of sulfuric acid, hydrochloric acid, nitric acid, orthophosphoric acid and acetic acid.

According to another embodiment of the present invention, a protective layer is formed on the large-scale graphene thin film 30 to prevent the large-scale graphene thin film from being damaged during subsequent processing. The protective layer may include at least one material selected from the group consisting of a high molecular polymer, a Photoresist (PR), an Electron Resist (ER), silicon oxide (SiOx), and aluminum oxide (AlOx) formed by spin coating; the high molecular polymer is selected from one or more of polymethyl methacrylate (PMMA), polycarbonate, polystyrene, polyethylene and polypropylene.

According to another embodiment of the present invention, the protective layer covering the surface of the large-scale graphene thin film 30 is dissolved and removed by using an organic solvent, which may be an acetone solution.

According to another embodiment of the present invention, the drying process includes drying with a vacuum oven, inclined standing for natural airing or heat drying.

Providing another embodiment, placing the first substrate 10 with the large-scale graphene thin film after drying under a microscope, applying a pressure of 10MPa through a microscope probe for 15min, and covering the first surface of the large-scale graphene thin film on the surface of the first substrate tightly, thereby preparing the large-scale ultra-smooth device. The large-size ultra-smooth device is placed on a flat substrate plane of 10cm for a sliding friction experiment, and the friction coefficient is 1.1 to 10^-3The abrasion is almost 0, and the requirement of ultra-smoothness is met.

Referring to fig. 3, another embodiment is provided, where a first substrate with a cylinder is selected: the first substrate 10 'is provided with a surface 101', the surface 101 'is micro-machined with uniformly arranged cylinders 102', the cross-sectional area of the cylinders is 30um, the height of the cylinders is 1um, and the distance between adjacent cylinders is 5 um; preparing a device with a large-scale graphene film by using a first substrate 10 with a cylinder, placing the device on a flat substrate plane of 10cm for a sliding friction experiment, wherein the friction coefficient is 1 x 10^-4The abrasion is almost 0, and the requirement of ultra-smoothness is met.

The above-described embodiments are only a few preferred embodiments of the present invention, and the present invention is not limited to these embodiments, and other variations should be allowed. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, structures, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Variations that fall within the scope of the independent claims or that can be easily ascertained by one of ordinary skill in the art based on the present invention are within the scope of the present invention.