ATOMIC-SMOOTH DEVICE WITH MICROSTRUCTURE, AND METHOD FOR PREPARING SAME

Abstract

Provided is an atomic-smooth device with a microstructure. The device includes, from the bottom to top, a substrate, a bonding material, a second dielectric layer on the substrate, the microstructure, and a first dielectric layer, where a surface of the first dielectric layer is an atomic-smooth surface. Further provided is a method for preparing an atomic-smooth device with a microstructure to effectively avoid pits or burrs generated when the existing microstructure is machined.

Claims

1. An atomic-smooth device with a microstructure, comprising: a substrate, a bonding material, a second dielectric layer on the substrate, the microstructure, and a first dielectric layer in sequence, wherein a surface of the first dielectric layer is an atomic-smooth surface.

2. The atomic-smooth device of claim 1, wherein the atomic-smooth surface has a diameter of 1 to 100 μm; and an edge of the atomic-smooth device has no burrs and an inner of the atomic-smooth device has no burrs or pits at least within a range of 10 μm×10 μm.

3. The atomic-smooth device of claim 1, wherein the first dielectric layer has a thickness of 2 to 100 nm; and both the first dielectric layer and the second dielectric layer are insulating layers.

4. The atomic-smooth device of claim 1, wherein the microstructure is a metal electrode; and the metal electrode preferably has a thickness of 10 to 150 nm.

5. A method for preparing the atomic-smooth device with the microstructure of claim 1, comprising: in step 1, growing the first dielectric layer on a surface of a two-dimensional material to obtain an atomic-smooth film; in step 2, preparing the microstructure on the first dielectric layer by micromachining; in step 3, growing the second dielectric layer on the microstructure; in step 4, coating the bonding material on the second dielectric layer; in step 5, connecting the second dielectric layer to the substrate through the bonding material; in step 6, peeling off the two-dimensional material to obtain a structure having a small amount of residual two-dimensional material, the first dielectric layer, the microstructure, the second dielectric layer, and the bonding material; in step 7, removing the small amount of residual two-dimensional material on the structure by oxygen plasma etching; and in step 8, obtaining the atomic-smooth device with the microstructure.

6. The method of claim 5, wherein the two-dimensional material is graphene or highly oriented pyrolytic graphite (HOPG), and both the first dielectric layer and the second dielectric layer are insulating layers.

7. The method of claim 5, wherein the microstructure is a metal electrode, and the metal electrode has a thickness of 10 to 150 nm.

8. The method of claim 5, wherein the bonding material is selected from at least one of ultraviolet (UV)-curable glue or resin.

9. The method of claim 5, wherein the substrate is selected from one or a combination of Silicon (Si), Silicon Carbide (SiC), Silicon-On-Insulator (SOI), sapphire, mica, graphene, or molybdenum disulfide.

10. The method of claim 5, wherein the atomic-smooth film has a diameter of 1 μm to 100 μm.

11. The atomic-smooth device of claim 1, wherein the microstructure, the first dielectric layer, and the second dielectric layer are heterogeneous materials, and no reaction occurs between the microstructure and the dielectric layers.

12. The atomic-scale flat device of claim 3, wherein the first dielectric layer and the second dielectric layer are silicon oxide layers and are prepared by deposition.

13. The atomic-scale flat device of claim 4, wherein the microstructure is Aurum (Au), Cuprum (Cu), or Argentum (Ag).

14. The atomic-scale flat device of claim 4, wherein the metal electrode has the thickness of 20 to 50 nm.

15. The method of claim 6, wherein the first dielectric layer and the second dielectric layer are silicon oxide layers and are prepared by deposition.

16. The method of claim 7, wherein the microstructure is Aurum (Au), Cuprum (Cu), or Argentum (Ag).

17. The method of claim 7, wherein the metal electrode has a thickness of 20 to 50 nm.

Description

DESCRIPTION OF DRAWINGS

[0030] FIG. 1 is a flowchart illustrating preparation process steps of an atomic-smooth device with a microstructure under a film according to present disclosure;

[0031] FIG. 2 is a flowchart illustrating preparation of an atomic-smooth device with a microstructure under a film according to present disclosure;

[0032] FIG. 3 is a flowchart illustrating preparation of a device with a microstructure through the existing process;

[0033] FIG. 4 is a schematic diagram illustrating that burrs and pits are generated during preparation of an atomic-smooth device through an existing etching method; and

[0034] FIG. 5 is an atomic force microscopy (AFM) scanning sectional diagram of a device surface obtained through an existing etching method.

DETAILED DESCRIPTION

[0035] Embodiment for Preparation of an Atomic-Smooth Device with Metal Electrodes Under a Film

[0036] A structure shown in step 8 of FIG. 1 is an atomic-smooth device with a metal electrode in this embodiment. The device includes, from bottom to top, a sapphire substrate, ultraviolet (UV)-curable glue, a second silicon oxide layer on the substrate, an Au electrode array arranged according to application requirements, and a first silicon oxide layer. A surface of the first silicon oxide layer is an atomic-smooth surface and has a diameter of 1 to 100 μm, and an Au electrode array under the first silicon oxide layer does not react with the first silicon oxide layer and the second silicon oxide layer. The edge of the atomic-smooth device has no burrs and the inner of the atomic-smooth device has no protrusions or pits at least within a range of 10 μm×10 μm.

[0037] In conjunction with FIGS. 1 and 2, a method for preparing a device according to an embodiment of the present disclosure is described, and the case where silicon oxide is used as insulating dielectric material, Au is used as a metal electrode, UV-curable glue is used as the binder, and sapphire is used as the substrate is used as an example. As shown in FIG. 1, first, HOPG is dissociated to obtain a new smooth surface; a 100 nm-thick first dielectric layer silicon oxide is next grown on the new smooth surface at low temperature; metal electrode plates of a capacitive superlubricity generator such as a 6×6×0.2 μm.sup.3 Au electrode array with an electrode interval of 6 μm are then made on silicon oxide; a 500 nm-thick second dielectric layer silicon oxide is then grown at low temperature and can completely cover the Au electrode array; a drop of UV-curable glue is then dripped on a silicon oxide surface of the second dielectric layer, and a glue dispenser is used to make the glue thickness about 100 μm; the UV-curable glue is then covered with a 1 mm-thick sapphire sheet with a size equivalent to the HOPG, the UV-curable glue is irradiated with a UV lamp so that the UV-curable glue and the sapphire sheet are bonded, and after irradiated for 1 min, the UV-curable glue is cured; since the HOPG is a layered material and the interlayer dissociation energy is relatively low, when the HOPG and sapphire are dissociated by the mechanical peeling method, the UV-curable glue, the second dielectric layer silicon oxide, Au electrodes, a silicon oxide film of the first dielectric layer, and part of the HOPG remain on the sapphire; the residual HOPG on the sapphire is finally bombarded with O.sup.2−-Plasma, and the bombardment time depends on the thickness of the residual HOPG. O.sup.2− does not react with silicon oxide, so after the HOPG is removed, a large-area atomic-smooth device with metal electrodes under the film may be obtained. The surface of the device is observed to be atomic-smooth under an atomic force microscope.

[0038] The large-area atomic-smooth device with the microstructure under the film prepared and obtained in the present disclosure has a diameter of up to 100 μm. The preparation method is simple and convenient, so as to effectively avoid pits or burrs generated when the existing microstructure is machined. Since a polishing process is not performed on surfaces of heterogeneous structures, the use of ultra-high-demand polishing equipment and processing technology in order to obtain a superlubricity smooth surface is avoided, thereby ensuring wide applicability.

[0039] Comparative Embodiment for Preparation of a Device with Metal Electrodes by the Existing Etching Method

[0040] In conjunction with FIGS. 3, 4 and 5, the preparation method and effect in the comparative embodiment of the present disclosure are described below, and the case of a silicon oxide substrate and Au electrodes is used as an example. FIG. 3 is a flowchart illustrating preparation of a device with a microstructure through the existing process. A layer of photoresist is first spin-coated on the silicon oxide substrate, a mask is used to expose the photoresist-coated substrate, and then a developer is used to wash off the exposed photoresist to form the pattern of the subsequent metal electrodes; then photolithography is performed to remove the silicon oxide of the metal electrode pattern on the silicon oxide substrate, that is, the vacant metal electrode pattern is pre-etched; then Au is evaporated on the vacant silicon oxide substrate, and a thickness of the evaporation is approximately the same as a thickness of the etching; then peeling off is performed, that is, a solution such as acetone is used to react with the photoresist to remove the photoresist and Au evaporated on the photoresist; then an insulating layer of silicon oxide is grown on the substrate to cover Au and silicon oxide.

[0041] FIG. 4 is a schematic diagram illustrating that burrs and pits are generated during preparation of an atomic-smooth device through an existing etching method. Due to different adsorption properties of the grown silicon oxide for Au and the silicon oxide substrate, growth rates of the grown silicon oxide on Au and the silicon oxide substrate are also different, resulting in some burrs or pits at the junction of Au and the silicon oxide substrate, thereby causing the junction to be not smooth. As shown in FIG. 5, the undulation is about tens of nanometers so that the atomic-smooth surface cannot be formed on the final device surface with the microstructure, especially at the edge. That is to say, it is difficult for the heterogeneous material layer to satisfy requirements of atomic-smooth, and it is difficult to achieve the atomic-smooth device with the microstructure under the film. Therefore, from the perspective of the existing common process means, it is difficult to solve the above-mentioned tens of nanometer protrusions or burrs so that requirements of the atomic-smooth surface cannot be satisfied.

INDUSTRIAL APPLICABILITY

[0042] The above are only preferred embodiments of the present disclosure. Any equivalent variations or modification made according to the scope of the claims in the present disclosure should belong to the coverage scope of the claims in the present disclosure.