阅读说明：本技术 一种超滑滑块的制备方法 (Preparation method of ultra-smooth sliding block ) 是由 郑泉水 瞿苍宇 于 2020-05-29 设计创作，主要内容包括：本发明提供了一种通过改进加载方式避免超滑滑块屈曲失稳及结构破坏的超滑滑块的制备方法,包括通过聚焦离子束刻蚀等方法,在探针尖端刻蚀出一个平台,用该平台与超滑滑块接触,并将加载方式改为使用探针从顶部接触超滑滑块,施加正压力和剪切力,从而推动滑块。本发明提出的方法简单便捷,可避免在超滑滑块较大时,滑块在探针推动下发生屈曲失稳从而收到破坏的问题。同时,本发明提出的方法能提高批量生产超滑滑块的成品率,并且具有广泛适用性。(The invention provides a preparation method of an ultra-smooth sliding block, which avoids buckling instability and structural damage of the ultra-smooth sliding block by improving a loading mode. The method provided by the invention is simple and convenient, and can avoid the problem that when the ultra-smooth slide block is large, the slide block is damaged due to buckling instability under the pushing of the probe. Meanwhile, the method provided by the invention can improve the yield of the ultra-smooth sliders produced in batches and has wide applicability.)

1. A preparation method of an ultra-smooth sliding block comprises the following steps,

the method comprises the following steps: covering at least photoresist on the highly oriented pyrolytic graphite;

step two: patterning the photoresist, and reserving a plurality of photoresist islands;

step three: etching the high-orientation pyrolytic graphite, and removing part of the high-orientation pyrolytic graphite which is not protected by the photoresist to form a plurality of island-shaped structures;

step four: detecting whether the island-shaped structures have super-smooth surfaces or not, wherein the island-shaped structures with the super-smooth shear surfaces on the lower surfaces are super-smooth sliders;

it is characterized in that the preparation method is characterized in that,

in step four, the step of detecting whether the plurality of island-shaped structures have the super-smooth surface comprises the following steps: the platform (6) is contacted with the sliding block from the top by controlling the probe with the platform (6) at the tip, and positive pressure and shearing force are exerted.

2. The method according to claim 1, wherein the photoresist is covered in the first step preferably by spin coating.

3. The production method according to claim 1 or 2, wherein the average diameter of the photoresist islands formed in the second step is preferably 1 μm to 30 μm, and the average interval between the photoresist islands is preferably 1 μm to 100 μm.

4. A method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the etching in step three is reactive ion etching.

5. The production method according to any one of claims 1 to 4, wherein the probe is a tungsten probe.

6. The method of claim 5, wherein the tungsten probe has a diameter of 0.1 to 0.5mm and a radius of curvature of a tip of 1 to 10 μm.

7. The method according to claim 6, wherein the platform (6) of the tungsten probe is formed by etching at the tip of the tungsten probe by focused ion beam etching.

8. The method of manufacturing according to claim 7, wherein the size of the platform (6) is close to the size of the island-like structure.

9. The method according to claims 1-8, characterized in that a connecting layer (7) is further provided between the platform (6) and the ultra-smooth slider (3).

10. Method for producing according to claim 9, characterized in that the material of the connection layer (7) is preferably SiO₂Preferably 50nm to 500nm thick, the SiO being deposited by plasma chemical vapor deposition₂And (7) connecting the layers.

Technical Field

The invention relates to the field of solid structure ultra-sliding, in particular to a preparation method of an ultra-sliding block, which avoids buckling instability and structural damage of the ultra-sliding block by improving a loading mode.

Technical Field

For a long time, friction and wear problems have been closely related not only to manufacturing, but also directly to energy, environment and health. Statistically, about one third of the world's energy is consumed during friction, and about 80% of machine component failures are caused by wear. The ultra-smooth structure is one of ideal schemes for solving the problem of frictional wear, and the ultra-smooth structure refers to the phenomenon that the friction and the wear between two atomic-level smooth and non-metric contact Van der Waals solid surfaces (such as two-dimensional material surfaces of graphene, molybdenum disulfide and the like) are almost zero. In 2004, the netherlands scientist j.frenken's research group measured the friction of a few nm-sized (total 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. In 2013, zhengquan professor discovered the ultra-slip phenomenon between hopg (high Oriented pyrolytic graphite) sheet materials for the first time at micron scale, which marks the transition of ultra-slip from basic research to applicable technical research process.

The existing method for preparing the micron-scale ultra-smooth sliding block is to form a plurality of micron-scale graphite islands on the surface of an HOPG material by coating and patterning photoresist, etching the photoresist and part of graphite which is not protected by the photoresist. And then pushing away the graphite islands in sequence to form a super-slip surface, thereby preparing the super-slip slider. In the preparation process of the ultra-smooth slide block, pushing away the graphite islands is an important step, and whether the available ultra-smooth slide block and the ultra-smooth sliding surface can be obtained or not is determined. Generally, the etching preparation process of the graphite island array is mature, and the success rate is high. However, in the process of pushing away the graphite island in the prior art, the situation that the ultra-smooth slider cannot be obtained due to the damaged graphite island occurs.

The existing method for pushing the ultra-smooth sliding block is to push the graphite island by a probe, and the loading mode of the probe is to push the sliding block by applying a lateral force through the contact of the probe with the side surface of the ultra-smooth sliding block. However, this loading method is liable to cause damage to the slider. Specifically, with the increase of the size of the ultra-smooth slider, the slider is pushed by using the existing probe pushing loading mode, so that the slider is buckled and unstable in the out-of-plane direction, and at the moment, the slider is structurally damaged due to plastic deformation, fracture and the like, so that the ultra-smooth sliding cannot be normally realized. In addition, the ultra-smooth slide block with the counter bore on the top surface is processed, and the conventional probe is used for contacting the slide block at the counter bore and pushing the slide block so as to avoid the buckling instability problem. The counter bore processing technology is complex, and if the pressure applied by the probe to the counter bore is too high, the damage to the top surface of the sliding block can still be caused.

In a word, the probe loading mode in the existing ultra-smooth slider preparation method may cause buckling instability of the slider and structural damage, so that a qualified ultra-smooth slider cannot be obtained. This reduces the yield of the ultra-smooth slider produced in batch, and therefore a simple method for manufacturing the ultra-smooth slider capable of solving the instability problem is required.

Disclosure of Invention

In order to solve the problem of instability of the ultra-smooth slider after the probe is loaded, the invention provides the following scheme: a platform is etched on a probe tip by methods such as focused ion beam etching and the like, the platform is used for contacting with the ultra-smooth sliding block, the loading mode is changed into a mode that the probe contacts with the ultra-smooth sliding block from the top, and positive pressure and shearing force are applied, so that the sliding block is pushed.

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

a preparation method of an ultra-smooth sliding block comprises the following steps,

the method comprises the following steps: covering at least photoresist on the highly oriented pyrolytic graphite;

step two: patterning the photoresist, and reserving a plurality of photoresist islands;

step three: etching the high-orientation pyrolytic graphite, and removing part of the high-orientation pyrolytic graphite which is not protected by the photoresist to form a plurality of island-shaped structures;

step four: detecting whether the island-shaped structures have super-smooth surfaces or not, wherein the island-shaped structures with the super-smooth shear surfaces on the lower surfaces are super-smooth sliders;

it is characterized in that the preparation method is characterized in that,

in step four, the step of detecting whether the plurality of island-shaped structures have the super-smooth surface comprises the following steps: the platform is contacted with the slide block from the top by controlling the probe with the platform at the tip, and applying positive pressure and shearing force.

According to another aspect of the invention, the photoresist in step one is preferably covered by spin coating.

According to another aspect of the present invention, the average diameter of the photoresist islands formed in the second step is 1 μm to 30 μm, and the average interval between the photoresist islands is 1 μm to 100 μm.

According to another aspect of the invention, the etching in step three is reactive ion etching.

According to another aspect of the invention, the probe is a tungsten probe.

According to another aspect of the present invention, the tungsten probe has a diameter of 0.1 to 0.5mm and a radius of curvature of a tip of 1 to 10 μm.

According to another aspect of the invention, the platform of the tungsten probe is formed by etching at the tip of the tungsten probe by focused ion beam etching.

According to another aspect of the invention, the size of the mesa is close to the size of the island structure.

According to another aspect of the invention, a connecting layer is arranged between the platform and the ultra-smooth sliding block 3.

According to another aspect of the invention, the material of the connection layer is SiO₂Preferably 50nm to 500nm thick, the SiO being deposited by plasma chemical vapor deposition₂And (7) connecting the layers.

The method provided by the invention is simple and convenient, and can avoid the problem that when the ultra-smooth slide block is large, the slide block is damaged due to buckling instability under the pushing of the probe. Meanwhile, the method provided by the invention can improve the yield of the ultra-smooth sliders produced in batches and has wide applicability.

Drawings

Fig. 1 shows a buckling instability phenomenon occurring when a conventional tungsten probe is loaded and a graphite island structure is pushed.

Fig. 2 shows a structure of a tungsten probe capable of preventing buckling instability of a graphite island-shaped structure and a process for manufacturing the same, wherein (b) is an enlarged view of a tip portion, and (c) is a tip after a stage is manufactured by focused ion beam etching.

FIG. 3 shows a process of pushing a graphite island structure with a tungsten probe with a platform to make an ultra-smooth slider.

FIG. 4 shows the process of pushing a graphite island structure with a connection layer using a tungsten probe with a platform to make an ultra-smooth slider.

Reference numerals

1. The method comprises the following steps of preparing an existing tungsten probe, 2, a graphite island substrate, 3, a graphite island sliding block, 4, a tungsten wire, 5, a tungsten probe tip part, 6, a tungsten probe tip platform, 7 and a connecting layer

Detailed Description

The method for manufacturing the ultra-smooth slider capable of avoiding buckling instability and structural damage according to the present invention will be described in detail below with reference to the attached drawings.

Step 1, covering a photoresist on the HOPG, wherein the photoresist can be covered in a spin coating mode.

And 2, patterning the photoresist and reserving a plurality of photoresist islands. The step of patterning the photoresist determines the layout of the island-like structures formed in the subsequent steps, for example, the photoresist can be patterned by using an electron beam etching method, the formed photoresist islands can have, for example, an average diameter of 1 μm to 30 μm, and the average spacing between the photoresist islands is 1 μm to 100 μm, so that the etched island-like structures also have corresponding average diameters and average spacings.

And 3, etching the substrate, and removing the part of the substrate which is not protected by the photoresist, thereby forming a plurality of island-shaped structures. The etching may be, for example, reactive ion etching.

And 4, using a tungsten probe with a platform at the tip end, and using a mechanical arm to push away the island-shaped structure one by one to detect whether the island-shaped structure has the super-smooth shearing surface, wherein in the island-shaped structure with self-recovery performance, the HOPG sheet structure with the super-smooth shearing surface on the lower surface is the super-smooth sliding block. The detailed steps of the preparation of the tungsten probe and the pushing away of the graphite island structure by the mechanical arm are as follows:

and (1) corroding a tip with the curvature radius of 1-10 mu m magnitude at the end part of the tungsten wire with the diameter of about 0.1-0.5 mm through electrochemical corrosion, thereby preparing and forming the tungsten probe.

And (2) etching a platform 6 with a size close to the graphite island structure to be pushed at a certain inclination angle at the tip of the tungsten probe by using techniques such as focused ion beam etching and the like, as shown in fig. 2.

And (3) as shown in fig. 3, operating the tungsten probe through the micro-nano mechanical arm to enable the platform 6 at the tip end of the tungsten probe to be in contact with the sliding block 3 from the top of the sliding block, and applying a certain positive pressure. The probe is then manipulated to apply a shear force to the slide in a horizontal direction. The positive pressure applied to the slider 3 by the platform 6 of the tungsten probe tip at this time inhibits buckling instability of the slider 3, and therefore the ultra-smooth slider can be sheared and slid without causing structural damage to the slider. Meanwhile, because the contact area between the platform 6 of the tungsten probe tip and the top of the sliding block 3 is large, the normal stress is low under the same positive pressure, and the structural damage of the sliding block is further avoided.

In particular, each ultra-smooth slider 3 may also have a connecting layer 7, for example SiO₂. The preparation method comprises the following steps:

step 1, covering a connecting layer and photoresist on the HOPG in sequence, wherein the connecting layer can be SiO₂The thickness may be, for example, 50nm to 500nm, and the SiO may be deposited by plasma chemical vapor deposition₂And (7) connecting the layers. The photoresist can be covered by spin coating.

And 2, patterning the photoresist and reserving a plurality of photoresist islands. The photoresist may be patterned, for example, by electron beam etching, and the formed photoresist islands may have, for example, an average diameter of 1 μm to 30 μm and an average spacing of 1 μm to 100 μm between the photoresist islands, so that the etched island structures also have corresponding average diameters and average spacings.

Step 3, etching the substrate to remove SiO unprotected by the photoresist₂Connecting the layers and portions of the substrate to form a plurality of layers with SiO₂An island structure of the connection layer.

And 4, using a special tungsten probe with a platform at the tip end, and using a mechanical arm to push away the island-shaped structure one by one to detect whether the island-shaped structure has the super-smooth shearing surface, wherein in the island-shaped structure with the self-recovery performance, the HOPG sheet structure with the super-smooth shearing surface on the lower surface is the super-smooth sliding block. The detailed steps of the preparation of the tungsten probe and the pushing away of the graphite island structure by the mechanical arm are as follows:

and (1) corroding a tip with the curvature radius of 1-10 mu m magnitude at the end part of the tungsten wire with the diameter of about 0.1-0.5 mm through electrochemical corrosion, thereby preparing and forming the tungsten probe.

And (2) etching a platform with a size close to the graphite island structure to be pushed at a certain inclination angle at the tip of the tungsten probe by using techniques such as focused ion beam etching and the like, as shown in fig. 2.

And (3) as shown in fig. 4, operating the tungsten probe through the micro-nano mechanical arm to enable the platform 6 at the tip end of the tungsten probe to be in contact with the sliding block from the top of the connecting layer 7 of the sliding block 3, and applying a certain positive pressure. The probe is then manipulated to apply a shear force to the slide 3 in the horizontal direction. The positive pressure applied by the platform 6 of the tungsten probe tip to the slider 3 at this time inhibits buckling instability of the slider. Meanwhile, the contact area between the platform 6 of the tungsten probe tip and the top of the sliding block is large, and the normal stress is low under the same positive pressure, so that the structural damage of the connecting layer can be avoided.

The above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above embodiment, but equivalent modifications or changes made by those skilled in the art according to the present disclosure should be included in the scope of the present invention as set forth in the appended claims.