阅读说明：本技术 一种自支撑碳基电容器靶及其制备方法 (Self-supporting carbon-based capacitor target and preparation method thereof ) 是由 彭丽萍 李朝阳 杨奇 樊龙 罗跃川 舒琳 湛治强 蒋涛 王雪敏 于 2021-09-26 设计创作，主要内容包括：本发明公开了一种自支撑碳基电容器靶及其制备方法,包括：利用直流磁控溅射技术在硅基底上制备Cr膜,再制备铜膜作为牺牲层,以此为衬底,制备微米厚度的α-C膜,利用光刻工艺、射频磁控溅射工艺、氧等离子体刻蚀工艺、湿法刻蚀工艺制备具有表面结构的α-C膜；利用脉冲激光沉积技术在抛光铜箔上制备DLC膜；将DLC膜的抛光铜箔熔去,并在去离子水中清洗多次；用有表面结构的α-C膜去捞漂浮在水面的DLC膜,然后溶解铜膜,得到碳基双层膜；把碳基双层膜在去离子水中清洗多次,用带圆孔的靶架捞出碳基双层膜,自然挥发干,得到自支撑碳基电容器靶。本发明能有效地实现自支撑碳基双层结构靶,操作方便,且该自支撑碳基电容器靶,有望在物理实验中取得预期结果。(The invention discloses a self-supporting carbon-based capacitor target and a preparation method thereof, wherein the self-supporting carbon-based capacitor target comprises the following steps: preparing a Cr film on a silicon substrate by using a direct-current magnetron sputtering technology, preparing a copper film as a sacrificial layer, preparing an alpha-C film with a micron thickness by using the Cr film as a substrate, and preparing the alpha-C film with a surface structure by using a photoetching technology, a radio-frequency magnetron sputtering technology, an oxygen plasma etching technology and a wet etching technology; preparing a DLC film on the polished copper foil by using a pulse laser deposition technology; melting off the polished copper foil of the DLC film, and cleaning the DLC film in deionized water for multiple times; removing the DLC film floating on the water surface by using the alpha-C film with the surface structure, and then dissolving the copper film to obtain a carbon-based double-layer film; and (3) cleaning the carbon-based double-layer film in deionized water for multiple times, fishing out the carbon-based double-layer film by using a target frame with a round hole, and naturally volatilizing to obtain the self-supporting carbon-based capacitor target. The invention can effectively realize the self-supporting carbon-based double-layer structure target, is convenient to operate, and is expected to obtain expected results in physical experiments.)

1. A self-supporting carbon-based capacitor target is characterized in that the carbon-based capacitor target is composed of two layers of carbon materials, wherein the thickness of the thick carbon layer is 1-2 mu m, and the thick carbon layer is amorphous carbon and is called an alpha-C film; the thin carbon layer is 50-100nm thick and is a diamond-like carbon called DLC film.

2. The self-supporting carbon-based capacitor target of claim 1, consisting of a skeletal structure supporting a DLC film by surface structuring of the α -C film.

3. A method of making a self-supporting carbon-based capacitor target according to claim 1 or 2, comprising the steps of:

preparing a Cr film on a silicon substrate by using a direct current magnetron sputtering technology, preparing a copper film as a sacrificial layer, preparing an alpha-C film with a micron thickness by using the Cr film as a substrate, and preparing a structural pattern with the line width of 2 mu m and the depth of 100nm +/-10 nm on the surface of the alpha-C film by using a photoetching technology, a radio frequency magnetron sputtering technology, an oxygen plasma etching technology and a wet etching technology to obtain the alpha-C film with a surface structure;

step two, preparing a DLC film with the thickness of 50-100nm on the polished copper foil with the thickness of 50 microns by using a pulse laser deposition technology;

step three, floating the DLC film to FeCl₃In the solution, the polished copper foil is melted off, and then the DLC film is transferred into deionized water for cleaning and then transferred into clean deionized water for cleaning again; removing DLC film floating on water surface with alpha-C film with surface structure, and floating to FeCl₃In the solution, obtaining a carbon-based double-layer film floating on the liquid surface after the copper sacrificial layer is dissolved; transferring the carbon-based double-layer film into deionized water for cleaning, and transferring into the deionized water again for cleaning;

and step four, fishing out the carbon-based double-layer film by using a target frame with a round hole with the diameter of 1mm, and naturally volatilizing water on the carbon-based double-layer film and the target frame to obtain the self-supporting carbon-based capacitor target for the physical experiment.

4. The method for preparing a carbon-based capacitor target according to claim 3, wherein in the first step, the Cr film is prepared by a direct-current magnetron sputtering technology, and the sputtering parameters are as follows: the purity of 3 inch target is better than 99.9%, and the backing vacuum is better than 4.0X 10^{- 4}Pa, sputtering power of 20-100W, and thickness of 15nm +/-5 nm.

5. The method for preparing a carbon-based capacitor target according to claim 3, wherein in the first step, the copper film is prepared by a direct current magnetron sputtering technology, and the sputtering parameters are as follows: the purity of the 3 inch target is better than that of the target99.9 percent, and the vacuum of the back bottom is better than 4.0 multiplied by 10^{- 4}Pa, sputtering power of 20-100W, and thickness of 100nm +/-20 nm.

6. The method for preparing a carbon-based capacitor target according to claim 3, wherein in the first step, the α -C film is prepared by a direct current magnetron sputtering method, and the sputtering parameters are as follows: the purity of 3 inch target is better than 99.999%, and the backing vacuum is better than 4.0X 10^-5Pa, sputtering power of 100W +/-10W and thickness of 1100nm +/-100 nm.

7. The method for preparing a carbon-based capacitor target according to claim 3, wherein in the first step, a photoresist pattern is formed on the surface of the α -C film by using a photolithography process, that is, a concave-convex surface is formed;

after the photoetching process, preparing SiO on the concave-convex surface by adopting a radio frequency magnetron sputtering process₂Film, removing the photoresist to form SiO₂A film relief surface;

etching SiO by oxygen plasma etching process₂Etching the exposed alpha-C film on the concave-convex surface of the film, and then etching the film by SiO₂The film remains unchanged;

removing SiO by wet etching process₂And (3) film, namely obtaining the alpha-C film with the surface structure.

8. The method of claim 7, wherein the parameters of the RF magnetron sputtering process are: the purity of 3 inch target is better than 99.9%, and the backing vacuum is better than 4.0X 10^-5Pa, the radio frequency power is 80W; SiO 2₂The thickness of the film is 500 nm;

the oxygen plasma etching process adopts an inductively coupled plasma etching process, and the parameters are as follows: the radio frequency bias power is 50-100W, and the power of the inductive coupling radio frequency source is 1500-3000W; the flow rate of He is 30-50 sccm; the oxygen flow is 20-40 sccm; the working pressure is 4-10 mtorr; the etching depth is 100nm +/-10 nm;

the parameters of the wet etching process are as follows: soaking the sample in 5-10 wt% sodium hydroxide solution for 3-5 hours to obtain SiO₂Film dissolution, alpha-C filmNo reaction takes place.

9. The method for preparing a carbon-based capacitor target according to claim 3, wherein the DLC film is prepared by pulsed laser deposition, wherein the laser has a wavelength of 248nm and a laser power density of 15W/mm²The thickness of the prepared DLC film is 50-100 nm.

10. The method of claim 3, wherein FeCl is added in step three₃The concentration of (A) is 10-50 wt%; in the fourth step, the thickness of the target holder is 100 μm +/-10 μm, and the diameter of the round hole is 1-11 mm.

Technical Field

The invention belongs to the field of preparation of structural materials, and particularly relates to a self-supporting carbon-based capacitor target and a preparation method thereof.

Background

The attosecond X-ray source is an important tool for detecting ultra-fast dynamics of substances with atomic scales, and has important application value in the fields of physics, biology, material science and the like. The femtosecond laser based on relativistic intensity drives a solid target to generate higher harmonics, which is considered as a main approach for obtaining an attosecond X-ray source with higher brightness and shorter pulses, but has the problems of too fast attenuation of harmonic intensity along with times or strict requirements on target parameters and the like. The carbon-based capacitor target is a target for a high-field physical experiment for generating high-strength attosecond pulses, cannot be replaced, and has not been applied internationally due to high preparation difficulty. The carbon-based capacitor target is composed of two layers of carbon materials with different thicknesses, the thickness of the thick film is 1-2 mu m, the thickness of the thin film is 50-100nm, and a distance of 100nm is formed between the two layers of films. To accommodate this requirement, a skeletal support may be employed between the two layers of carbon.

The preparation of the carbon layer is mainly realized by adopting a vacuum coating mode, and pulse laser deposition and magnetron sputtering are two more common modes in all the vacuum coating modes. The growth speed of the pulse laser deposition technology is low, the density of the prepared film is high, the thickness control is accurate, and the method is suitable for preparing films with lower thickness. The magnetron sputtering has high growth speed and is suitable for preparing various metal and nonmetal film layers with the thickness of more than one hundred nanometers.

Disclosure of Invention

An object of the present invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.

To achieve these objects and other advantages in accordance with the present invention, there is provided a self-supporting carbon-based capacitor target comprised of two layers of carbon material, wherein the thick carbon layer has a thickness of 1-2 μm and is an amorphous structure carbon, referred to as an α -C film; the thin carbon layer is 50-100nm thick and is a diamond-like carbon called DLC film.

Preferably, the carbon-based capacitor target is composed of a skeleton structure supported by a DLC film through surface structuring of an α -C film.

The invention also provides a preparation method of the self-supporting carbon-based capacitor target, which comprises the following steps:

preparing a Cr film on a silicon substrate by using a direct current magnetron sputtering technology, preparing a copper film as a sacrificial layer, preparing an alpha-C film with a micron thickness by using the Cr film as a substrate, and preparing a structural pattern with the line width of 2 mu m and the depth of 100nm +/-10 nm on the surface of the alpha-C film by using a photoetching technology, a radio frequency magnetron sputtering technology, an oxygen plasma etching technology and a wet etching technology to obtain the alpha-C film with a surface structure;

step two, preparing a DLC film with the thickness of 50-100nm on the polished copper foil with the thickness of 50 microns by using a pulse laser deposition technology;

step three, floating the DLC film to FeCl₃In the solution, the polished copper foil is melted off, and then the DLC film is transferred into deionized water for cleaning and then transferred into clean deionized water for cleaning again; removing DLC film floating on water surface with alpha-C film with surface structure, and floating to FeCl₃In solution, treat copper sacrificeDissolving the layer to obtain a carbon-based double-layer film floating on the liquid level; transferring the carbon-based double-layer film into deionized water for cleaning, and transferring into the deionized water again for cleaning;

and step four, fishing out the carbon-based double-layer film by using a target frame with a round hole with the diameter of 1mm, and naturally volatilizing water on the carbon-based double-layer film and the target frame to obtain the self-supporting carbon-based capacitor target for the physical experiment.

Preferably, in the step one, the Cr film is prepared by a dc magnetron sputtering technique, and the sputtering parameters are as follows: the purity of 3 inch target is better than 99.9%, and the backing vacuum is better than 4.0X 10^-4Pa, sputtering power of 20-100W, and thickness of 15nm +/-5 nm.

Preferably, in the step one, the copper film is prepared by a direct current magnetron sputtering technology, and the sputtering parameters are as follows: the purity of 3 inch target is better than 99.9%, and the backing vacuum is better than 4.0X 10^-4Pa, sputtering power of 20-100W, and thickness of 100nm +/-20 nm.

Preferably, in the step one, the α -C film is prepared by a direct current magnetron sputtering method, and the sputtering parameters are as follows: the purity of 3 inch target is better than 99.999%, and the backing vacuum is better than 4.0X 10^-5Pa, sputtering power of 100W +/-10W and thickness of 1100nm +/-100 nm.

Preferably, in the step one, a photoresist pattern is formed on the surface of the alpha-C film by adopting a photoetching process, namely a concave-convex surface is formed;

after the photoetching process, preparing SiO on the concave-convex surface by adopting a radio frequency magnetron sputtering process₂Film, removing the photoresist to form SiO₂A film relief surface;

etching SiO by oxygen plasma etching process₂Etching the exposed alpha-C film on the concave-convex surface of the film, and then etching the film by SiO₂The film remains unchanged;

removing SiO by wet etching process₂And (3) film, namely obtaining the alpha-C film with the surface structure.

Preferably, the parameters of the radio frequency magnetron sputtering process are as follows: the purity of 3 inch target is better than 99.9%, and the backing vacuum is better than 4.0X 10^-5Pa, the radio frequency power is 80W; SiO 2₂The thickness of the film is 500 nm;

the oxygen plasma etching process adopts an inductively coupled plasma etching process, and the parameters are as follows: the radio frequency bias power is 50-100W, and the power of the inductive coupling radio frequency source is 1500-3000W; the flow rate of He is 30-50 sccm; the oxygen flow is 20-40 sccm; the working pressure is 4-10 mtorr; the etching depth is 100nm +/-10 nm;

the parameters of the wet etching process are as follows: soaking the sample in 5-10 wt% sodium hydroxide solution for 3-5 hours to obtain SiO₂The membrane dissolves and the alpha-C membrane does not react.

Preferably, in the second step, the DLC film is prepared by pulsed laser deposition technology, wherein the wavelength of the laser is 248nm, and the laser power density is 15W/mm²The thickness of the prepared DLC film is 50-100 nm.

Preferably, in step three, FeCl₃The concentration of (A) is 10-50 wt%.

Preferably, in the fourth step, the thickness of the target holder is 100 μm +/-10 μm, and the diameter of the circular hole is 1-11 mm.

The invention at least comprises the following beneficial effects: the preparation method provided by the invention can effectively realize the self-supporting carbon-based double-layer structure target, does not need special equipment, is convenient to operate and has short preparation period. The self-supporting carbon-based capacitor target prepared by the method is expected to obtain expected results in physical experiments.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Description of the drawings:

FIG. 1 is a schematic flow diagram of a process for preparing a self-supporting carbon-based capacitor target according to the present invention;

FIG. 2 shows that the alpha-C film having a surface structure floats to FeCl after the DLC film is fished up in step three of example 1 of the present invention₃Photo of the real object in the solution;

FIG. 3 is a photograph of a carbon-based bilayer film transferred to deionized water in step three of example 1 according to the present invention;

FIG. 4 is a photograph of a carbon-based double-layer film floating in deionized water in step three of example 1 according to the present invention;

FIG. 5 is a photomicrograph of a self-supporting carbon-based capacitor target made in example 1 of the invention.

The specific implementation mode is as follows:

the present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the invention by referring to the description text.

It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.

Example 1:

a self-supporting carbon-based capacitor target is characterized in that the carbon-based capacitor target is composed of two layers of carbon materials, wherein the thickness of the thick carbon layer is 1 mu m, and the thick carbon layer is amorphous carbon and is called an alpha-C film; the thin carbon layer is 50nm thick and is diamond-like carbon called DLC film; the carbon-based capacitor target is formed by carrying out surface structuring treatment on an alpha-C film to form a skeleton structure and supporting a DLC film by the skeleton structure.

A preparation method of the carbon-based capacitor target comprises the following steps:

preparing a 10nm Cr film on a silicon substrate by using a direct current magnetron sputtering technology, preparing a 100nm copper film as a sacrificial layer, preparing an alpha-C film with the thickness of 1 mu m by using the Cr film as the substrate, and preparing a structural pattern with the line width of 2 mu m and the depth of 100nm +/-10 nm on the surface of the alpha-C film by using a photoetching technology, a radio frequency magnetron sputtering technology, an oxygen plasma etching technology and a wet etching technology to obtain the alpha-C film with a surface structure;

the Cr film is prepared by adopting a direct-current magnetron sputtering technology, and the sputtering parameters are as follows: the purity of 3 inch target is better than 99.9%, and the backing vacuum is better than 4.0X 10^-4Pa, and the sputtering power is 80W.

The copper film is prepared by adopting a direct current magnetron sputtering technology, and the sputtering parameters are as follows: the purity of 3 inch target is better than 99.9%, and the backing vacuum is better than 4.0X 10^-4Pa, sputtering power of 80W;

the alpha-C film is prepared by a direct-current magnetron sputtering method, and the sputtering parameters are as follows: the purity of the 3 inch target is better than 99.999 percentThe bottom vacuum is better than 4.0 multiplied by 10^-5Pa, sputtering power of 110W;

forming a photoresist pattern on the surface of the alpha-C film by adopting a photoetching process, namely forming a concave-convex surface;

after the photoetching process, preparing SiO on the concave-convex surface by adopting a radio frequency magnetron sputtering process₂Film, removing the photoresist to form SiO₂A film relief surface;

etching SiO by oxygen plasma etching process₂Etching the exposed alpha-C film on the concave-convex surface of the film, and then etching the film by SiO₂The film remains unchanged;

removing SiO by wet etching process₂Film, namely obtaining the alpha-C film with the surface structure;

the parameters of the radio frequency magnetron sputtering process are as follows: the purity of 3 inch target is better than 99.9%, and the backing vacuum is better than 4.0X 10^-5Pa, the radio frequency power is 80W; SiO 2₂The thickness of the film is 500 nm;

the oxygen plasma etching process adopts an inductively coupled plasma etching process, and the parameters are as follows: the radio frequency bias power is 100W, and the power of the inductive coupling radio frequency source is 2500W; the flow rate of He is 40 sccm; the oxygen flow is 30 sccm; the working pressure is 6 mtorr; the etching depth is 100nm +/-10 nm;

the parameters of the wet etching process are as follows: the sample was soaked in 10wt% sodium hydroxide solution for 3 hours, SiO₂The film is dissolved, and the alpha-C film does not react;

step two, preparing a DLC film with the thickness of 50nm on a polished copper foil with the thickness of 50 mu m by using a pulse laser deposition technology; wherein, the preparation method of the DLC film is a pulse laser deposition technology, the wavelength of the adopted laser is 248nm, and the laser power density is 15W/mm²；

Step three, floating the DLC film to FeCl₃In the solution, the polished copper foil is melted off, and then the DLC film is transferred into deionized water for cleaning and then transferred into clean deionized water for cleaning again; removing DLC film floating on water surface with alpha-C film with surface structure, and floating to FeCl₃In the solution, obtaining a carbon-based double-layer film floating on the liquid surface after the copper sacrificial layer is dissolved; transferring the carbon-based bilayer film to deionizationWashing in the sub-water, and transferring to the deionized water again for washing; FeCl₃Is 30 wt%;

and step four, fishing out the carbon-based double-layer film by using a target frame with a circular hole with the diameter of 1mm and the thickness of 100 mu m, and naturally volatilizing water on the carbon-based double-layer film and the target frame to obtain the self-supporting carbon-based capacitor target for the physical experiment.

Example 2:

a self-supporting carbon-based capacitor target is characterized in that the carbon-based capacitor target is composed of two layers of carbon materials, wherein the thickness of the thick carbon layer is 1.5 mu m, and the thick carbon layer is amorphous carbon and is called an alpha-C film; the thin carbon layer has a thickness of 100nm and is a diamond-like carbon, called DLC film; the carbon-based capacitor target is formed by carrying out surface structuring treatment on an alpha-C film to form a skeleton structure and supporting a DLC film by the skeleton structure.

A preparation method of the carbon-based capacitor target comprises the following steps:

step one, preparing a layer of 10nm Cr film on a silicon substrate by using a direct current magnetron sputtering technology, then preparing a layer of 100nm copper film as a sacrificial layer, and preparing an alpha-C film with the thickness of 1.5 mu m by using the sacrificial layer as the substrate,

preparing a structural pattern with the line width of 2 mu m and the depth of 100nm +/-10 nm on the surface of the alpha-C film by utilizing a photoetching process, a radio frequency magnetron sputtering process, an oxygen plasma etching process and a wet etching process to obtain the alpha-C film with a surface structure;

the Cr film is prepared by adopting a direct-current magnetron sputtering technology, and the sputtering parameters are as follows: the purity of 3 inch target is better than 99.9%, and the backing vacuum is better than 4.0X 10^-4Pa, and the sputtering power is 80W.

The copper film is prepared by adopting a direct current magnetron sputtering technology, and the sputtering parameters are as follows: the purity of 3 inch target is better than 99.9%, and the backing vacuum is better than 4.0X 10^-4Pa, sputtering power of 80W;

the alpha-C film is prepared by a direct-current magnetron sputtering method, and the sputtering parameters are as follows: the purity of 3 inch target is better than 99.999%, and the backing vacuum is better than 4.0X 10^-5Pa, sputtering power of 110W;

forming a photoresist pattern on the surface of the alpha-C film by adopting a photoetching process, namely forming a concave-convex surface;

after the photoetching process, preparing SiO on the concave-convex surface by adopting a radio frequency magnetron sputtering process₂Film, removing the photoresist to form SiO₂A film relief surface;

etching SiO by oxygen plasma etching process₂Etching the exposed alpha-C film on the concave-convex surface of the film, and then etching the film by SiO₂The film remains unchanged;

removing SiO by wet etching process₂Film, namely obtaining the alpha-C film with the surface structure;

the parameters of the radio frequency magnetron sputtering process are as follows: the purity of 3 inch target is better than 99.9%, and the backing vacuum is better than 4.0X 10^-5Pa, the radio frequency power is 80W; SiO 2₂The thickness of the film is 500 nm;

the oxygen plasma etching process adopts an inductively coupled plasma etching process, and the parameters are as follows: the radio frequency bias power is 100W, and the power of the inductive coupling radio frequency source is 2500W; the flow rate of He is 40 sccm; the oxygen flow is 30 sccm; the working pressure is 6 mtorr; the etching depth is 100nm +/-10 nm;

the parameters of the wet etching process are as follows: the sample was soaked in 5 wt% sodium hydroxide solution for 5 hours, SiO₂The film is dissolved, and the alpha-C film does not react;

step two, preparing a DLC film with the thickness of 100nm on the polished copper foil with the thickness of 50 mu m by using a pulse laser deposition technology; wherein, the preparation method of the DLC film is a pulse laser deposition technology, the wavelength of the adopted laser is 248nm, and the laser power density is 15W/mm²；

Step three, floating the DLC film to FeCl₃In the solution, the polished copper foil is melted off, and then the DLC film is transferred into deionized water for cleaning and then transferred into clean deionized water for cleaning again; removing DLC film floating on water surface with alpha-C film with surface structure, and floating to FeCl₃In the solution, obtaining a carbon-based double-layer film floating on the liquid surface after the copper sacrificial layer is dissolved; transferring the carbon-based double-layer film into deionized water for cleaning, and transferring into the deionized water again for cleaning; FeCl₃Is 35 wt%;

and step four, fishing out the carbon-based double-layer film by using a target frame with a circular hole with the diameter of 1mm and the thickness of 100 mu m, and naturally volatilizing water on the carbon-based double-layer film and the target frame to obtain the self-supporting carbon-based capacitor target for the physical experiment.

FIG. 1 is a schematic view of a process flow of the present invention for preparing a self-supporting carbon-based capacitor target, wherein a is a photoresist pattern formed on the surface of an α -C film by a photolithography process, i.e., a concave-convex surface is formed; b is to adopt a radio frequency magnetron sputtering process to prepare SiO on the concave-convex surface₂A film; c is removing the photoresist to form SiO₂A film relief surface; d is etching SiO by oxygen plasma etching process₂Etching the exposed alpha-C film on the concave-convex surface of the film, and then etching the film by SiO₂The film remains unchanged; e is removing SiO by wet etching process₂Film, namely obtaining the alpha-C film with the surface structure; f is a structure formed by removing the DLC film floating on the water surface by using the alpha-C film with the surface structure; g is the self-supporting carbon-based capacitor target obtained after dissolving the copper sacrificial layer.

While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.