A method for preventing photoresist degradation in oxygen plasma etching graphene based on an isolation layer

Abstract

This invention belongs to the field of semiconductor processes and devices, specifically relating to a method for preventing photoresist degradation during oxygen plasma etching of graphene based on an isolation layer. The method comprises the following steps: transferring graphene onto a substrate using mechanical exfoliation and transfer techniques; exposing the two ends of the graphene to the environment using photolithography, and depositing Se as an isolation layer onto the developed graphene pattern; covering with photoresist to protect the Se from subsequent etching, and then performing photolithography to form graphene channels; treating the photoresist-covered graphene substrate with oxygen plasma to etch the graphene channels; and finally annealing to remove the Se. This invention is applicable to the manufacture of semiconductor devices and has broad application prospects in the microfabrication, patterning, and functionalization of graphene-based materials. It can be used in the fabrication processes of graphene integrated circuits, graphene sensors, optoelectronic devices, and other microelectronic devices, particularly promoting high-precision graphene processing.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor processes and devices, and specifically relates to a method for preventing photoresist degradation during the oxygen plasma etching process of graphene based on an isolation layer. Background Technology

[0002] Graphene, as a novel structural form of carbon discovered after fullerenes and carbon nanotubes, is composed of sp... 2 Hybridized carbon atoms arrange themselves in a hexagonal lattice to form a honeycomb structure, making it a strictly two-dimensional material. Since its first report in 2004, graphene has rapidly emerged in the fields of physics and materials science, becoming an important material for basic scientific research and the development of emerging technologies. Its unique two-dimensional quantum system properties have overturned the theory that traditional two-dimensional crystals cannot exist stably. In particular, the transport properties of massless Dirac fermions give it extremely high carrier mobility, room-temperature quantum Hall effect, and micrometer-scale electronic coherence, bringing revolutionary breakthroughs to the development of condensed matter physics. At the same time, it shows broad application prospects in micro- and nano-electronic devices, high-performance batteries, gas sensors, and terahertz technology.

[0003] However, the intrinsic zero bandgap characteristic of graphene limits its application in logic circuits and transistor devices. Therefore, introducing a bandgap and modulating its physical properties has become a key focus of scientific research. To address this issue, scientists have proposed several methods: inducing symmetry breaking by applying an external electric or chemical potential field to split Landau levels in bilayer graphene, which is an effective means of bandgap manipulation; constructing graphene nanoribbons and other structures through quantum confinement effects, and using bandwidth adjustment to achieve precise bandgap control; using chemical vapor deposition (CVD) to introduce a bandgap in graphene and adjust its size by doping with elements such as boron (B) and nitrogen (N); and using epitaxial growth on silicon carbide substrates to achieve bandgap modulation through substrate-induced effects. These methods offer various possibilities for overcoming the limitations of graphene in logic devices, but achieving high-quality graphene patterning requires controllable dimensions, specific orientation, and atomically smooth edges during processing, which places higher demands on the etching and trimming of graphene.

[0004] Currently, there are three common processing methods for etching and patterning graphene surfaces: patterned exposure etching, chemical trimming, and probe technology. Patterned exposure etching uses a PMMA mask for electron beam exposure and oxygen plasma etching, but the edge roughness is relatively large (>5nm). Chemical trimming prepares graphene nanoribbons using chemical methods, achieving an edge roughness of less than 5nm. Although the edges are smoother, the size is difficult to control and impurities may be introduced. Although researchers at the Institute of Metal Research, Chinese Academy of Sciences, proposed a method for the large-scale controllable preparation of graphene ribbons using chemical trimming in 2009, the trimming precision is still limited due to its reliance on ultrasonic shearing and chemical reduction. Removing large, incompletely trimmed graphene sheets may face problems of low efficiency and high cost, and may also lead to the incorrect retention of some non-compliant graphene ribbons. In comparison, probe technology uses scanning tunneling microscope probes or atomic force microscope anodic oxidation technology for etching, which has high precision but low efficiency and is not suitable for large-scale applications. For example, in 2018, Chen Jianmei of Soochow University published a paper on polymer surface patterning and application based on atomic force probe etching technology. Scanning probe processing technology optimizes the etching precision, but large-scale integrated production is affected by cost.

[0005] In summary, while various surface etching methods for graphene possess unique characteristics, they all generally have limitations. In contrast, patterned etching offers greater potential for high-precision and large-scale processing due to its ability to achieve precise dimensional control and highly customizable patterning, demonstrating significant advantages. However, oxygen plasma etching is extremely prone to photoresist degradation, and the degraded photoresist remains in the etching channels, making it difficult to remove. If this problem can be solved, the application scope of patterned etching in semiconductor manufacturing will be significantly expanded. Summary of the Invention

[0006] During oxygen plasma etching of graphene, the photoresist is exposed to high-energy ions and reactive oxygen atoms, making it prone to chemical reactions and causing photoresist degradation. This degradation and degradation of the photoresist affects the etching precision, edge quality, and surface cleanliness of the graphene.

[0007] To address the aforementioned technical problems, this application provides the following technical solution:

[0008] To address the issue of photoresist degradation during plasma etching, this invention proposes a novel method by introducing an isolation layer between the photoresist and graphene, combined with a gentle plasma etching technique. This method effectively controls the contact between the photoresist and graphene, preventing photoresist damage during etching and thus improving the patterning quality of the graphene. A key feature is the use of an isolation layer to protect the photoresist, preventing its degradation and ensuring the integrity of the graphene during etching. This method is simple to operate, low in cost, and enables high-precision graphene processing, making it widely applicable in the fabrication of high-performance graphene devices.

[0009] This invention provides a method for preventing photoresist degradation during oxygen plasma etching of graphene based on an isolation layer, comprising the following steps:

[0010] S11: Transfer the graphene film onto the surface of the substrate to obtain a substrate with graphene.

[0011] S12: Coat the substrate with graphene with photoresist, bake, and photolithographically develop to form a patterned photoresist mask;

[0012] S13: Selenium (Se) is deposited on the pattern of the photoresist mask and then the photoresist is washed off to form a sample; the sample includes trench I not covered by selenium and a selenium isolation layer protecting the graphene;

[0013] S14: Coat the surface of the sample from step S13 with photoresist, bake, and photolithographically develop to form trench II, thereby obtaining graphene after secondary development; the trench II includes trench I that is not covered by selenium.

[0014] S15: The graphene after secondary development is etched using oxygen plasma to obtain plasma-etched graphene.

[0015] S16: After washing away the photoresist from the plasma-etched graphene, anneal it to obtain the graphene channel based on the isolation layer to prevent photoresist degradation during oxygen plasma etching.

[0016] Preferably, in step S11, the substrate is a silicon-based substrate, which is ultrasonically cleaned, dried, and baked in acetone, ethanol, and water in sequence before transfer to remove residues such as acetone and ethanol.

[0017] Furthermore, the frequency of the ultrasonic cleaning is 20-25 kHz.

[0018] Specifically, in step S11, before the substrate transfer, the silicon substrate is first placed in acetone and ultrasonically cleaned for 4-6 minutes; then the silicon substrate is placed in ethanol and ultrasonically cleaned for 4-6 minutes; then ultrasonically cleaned in deionized water for 4-6 minutes, then dried with a nitrogen gun, and finally baked on a heating platform at 300±10℃ for 9-10 minutes.

[0019] Preferably, the photoresist is of type AZ5214E.

[0020] Preferably, the thickness of the graphene film is 5-10 nm.

[0021] Preferably, in step S11, the graphene film is transferred using a PDMS dry transfer method.

[0022] Preferably, in step S12, the method for coating the photoresist is: spin coating at a speed of 580-620 rpm for 9-10 seconds, or spin coating at a speed of 2970-3030 rpm for 25-35 seconds.

[0023] Preferably, in step S12, the baking temperature is 100°C and the baking time is 90 seconds.

[0024] Preferably, in step S12, the photolithography development method is as follows: the graphene is placed on the stage of a maskless photolithography machine, the trench I to be protected is aligned under a microscope and masked, and the remaining areas of the sample are exposed to ensure that the photoresist can be removed in the subsequent development step, thereby forming a photoresist mask to protect the trench area on the graphene sample, while the remaining areas are exposed.

[0025] Preferably, the width of the groove I is 9.5-10.5 μm.

[0026] Preferably, in step S13, the method for evaporating selenium is thermal evaporation; during thermal evaporation, the vacuum condition of the evaporation machine is 1×10⁻⁶. -4 Below Pa, the evaporation rate is The time was 30 minutes, and the resulting material thickness was 50 nm. Se was used to cover the part that was not protected by the photoresist mask in the previous step, serving as a protective layer.

[0027] Preferably, in step S14, the developing solution used in photolithography is a mixture of an aqueous solution containing 25 wt% tetramethylammonium hydroxide and water, with a volume ratio of 25:3.

[0028] Preferably, in step S15, the oxygen purity in the oxygen plasma is 5N and the gas flow rate is 20 sccm.

[0029] Preferably, in step S16, the annealing temperature is 250-300℃ and the time is 5-6 hours, after which the Se isolation layer disappears.

[0030] The present invention also provides a graphene channel prepared by the above method.

[0031] Preferably, an In2Se3 thin layer is transferred onto the graphene channel, and a gold electrode is deposited on the graphene to obtain a complete device and test the output characteristic curve.

[0032] Furthermore, the method for transferring the In2Se3 thin layer is dry transfer; during thermal gold deposition, the vacuum conditions of the deposition machine are 1×10⁻⁶. -4 Below Pa, the evaporation rate is The time was 30 minutes, and the material thickness was 50 nm, thus obtaining a complete device for testing the output characteristic curve and verifying the feasibility of the method.

[0033] The technical solution of the present invention has the following advantages compared with the prior art:

[0034] (1) This invention combines photolithography, vapor deposition and plasma etching in a multi-step process to precisely form trenches and isolation layers on the surface of graphene, effectively preventing damage or denaturation of graphene during oxygen plasma etching and ensuring the structural integrity of graphene.

[0035] (2) The present invention uses photoresist mask and evaporated selenium as protective layer design, which can accurately control the area to be etched and avoid photoresist from deteriorating in subsequent steps, ensuring high-precision processing of graphene channel area, and is suitable for the fabrication of high-performance devices.

[0036] (3) By precisely controlling the processing conditions of the photoresist and adopting appropriate annealing and etching processes, the present invention avoids the adverse degradation of the photoresist in plasma etching, ensures the protective effect of the photoresist on graphene, and enhances the selectivity and stability of the photoresist.

[0037] (4) By introducing a Se protective layer and oxygen plasma etching, the present invention can effectively protect the edge structure of graphene during the etching process, so that the groove area of ​​graphene maintains atomic-level flatness, avoids edge contamination and damage, and improves the quality of graphene material.

[0038] (5) The method of the present invention is simple and easy to operate, and can complete the processing and patterning of graphene in a short time. It is suitable for large-scale production and practical application, which improves production efficiency and reduces processing costs.

[0039] (6) This invention can effectively prevent photoresist degradation in graphene etching, and can also be used for other two-dimensional materials etched by oxygen plasma. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the process and application of oxygen plasma etching of graphene based on a Se isolation layer prepared in Example 1;

[0041] Figure 2 This is an optical mirror image of the Se vapor deposition and graphene etching process performed in Example 1.

[0042] Figure 3 This is a schematic diagram of the optical microscope of the annealed graphene in Example 1;

[0043] Figure 4 This is a graph showing the output characteristics of the gold electrode after etching and transferring In2Se3 into the graphene.

[0044] Figure 5 This is an optical micrograph of the results of oxygen plasma etching of graphene without an isolation layer prepared in Comparative Example 1. Detailed Implementation

[0045] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0046] Graphene films are prepared by mechanical exfoliation. The specific steps are as follows: first, a portion of the sample is adhered to the surface of the graphene crystal with blue adhesive, then the adhesive tapes are torn apart from each other. This process is repeated about ten times until the sample remaining on the adhesive tape turns gray, at which point the graphene film is obtained.

[0047] PDMS dry transfer technology: A graphene-containing tape is attached to the PDMS surface. After standing for 1 hour, the tape is peeled off, leaving a graphene sample on the polydimethylsiloxane (PDMS) surface. Then, a treated silicon substrate is attached to the PDMS surface. After standing for another 30 minutes, the silicon substrate is peeled off, and the graphene sample is transferred to the substrate surface.

[0048] The PDMS substrate used was prepared by ourselves. During preparation, Dow Corning SYLGARD 184 silicone rubber and curing agent were mixed at a weight ratio of 10:1 and stirred evenly. After all the bubbles disappeared, it was left to stand in the refrigerator (4°C) for 48 hours to solidify and form a transparent film.

[0049] The selenium prepared by thermal evaporation; the vacuum conditions of the evaporation machine must meet 1×10 -3 Below Pa, the evaporation rate used is The time was approximately 25 minutes, and the resulting electrode material had a thickness of 50 nm.

[0050] In2Se3 thin films were prepared by mechanical exfoliation. The specific steps were as follows: first, a portion of the sample was adhered to the surface of the In2Se3 crystal with blue adhesive, and then the adhesive tapes were peeled off one another. This process was repeated about ten times until the sample remaining on the adhesive tapes turned gray, at which point the In2Se3 thin film was obtained.

[0051] In2Se3 dry transfer procedure: Apply In2Se3-containing tape to the PDMS surface and allow it to stand for 1 hour. Then peel off the tape, leaving a graphene sample on the polydimethylsiloxane (PDMS) surface. Precisely observe the graphene sample on the PDMS surface and the silicon substrate using an optical microscope to ensure accurate alignment of the thin In2Se3 layer with the graphene surface. After alignment, heat both the PDMS and graphene samples to 70°C to ensure full contact and adhesion between the In2Se3 layer and the graphene surface. Gently apply pressure to firmly adhere the layer to the graphene, completing the transfer.

[0052] The gold prepared by thermal evaporation; the vacuum conditions of the evaporation machine must meet 1×10 -3 Below Pa, the evaporation rate used is The time was approximately 25 minutes, and the resulting electrode material had a thickness of 50 nm.

[0053] Example 1

[0054] This embodiment provides a method for preventing photoresist degradation during oxygen plasma etching of graphene based on an isolation layer. The process is as follows: Figure 1 The steps are as follows:

[0055] (1) First, place the silicon substrate in acetone and ultrasonically clean it for 5 minutes; then place the silicon substrate in ethanol and ultrasonically clean it for 5 minutes; then ultrasonically clean it in deionized water for 5 minutes; then dry it with a nitrogen gun; finally bake it on a heating platform at 300°C for 10 minutes.

[0056] (2) A few-layer graphene film was obtained by mechanical exfoliation and transferred to the surface of the cleaned substrate in step (1) by PDMS dry transfer technology to obtain a substrate with graphene.

[0057] (3) The photoresist is uniformly spin-coated onto the graphene-containing substrate prepared in step (2) at a spin speed of 600 rpm for 10 s and 3000 rpm for 30 s, followed by baking. The graphene is then placed on the stage of a maskless lithography machine, aligned with the channel area to be protected under a microscope, and masked, ensuring its width is 10 ± 0.5 μm. The remaining areas of the sample are exposed to ensure that the photoresist can be removed in the subsequent development step, thereby forming a photoresist mask on the graphene sample to protect the channel area, leaving the remaining areas exposed.

[0058] (4) Place the developed graphene from step (3) into a vapor deposition machine and vapor deposit Se. The vacuum condition of the vapor deposition machine is 1×10⁻⁶. - 3 Below Pa, the evaporation rate used is The time was 30 minutes, and the thickness of the electrode material obtained was 50 nm. After washing away the photoresist, the trenches not covered by selenium were obtained. These trenches are the areas that need to be etched later. The remaining areas covered by selenium are the isolation layer that protects the graphene.

[0059] (5) The graphene after evaporation treatment in step (4) is spin-coated with photoresist again and baked. The trenches obtained after photolithography and development are exposed to the environment (Se is on the trenches), and the rest are isolated from the environment with photoresist.

[0060] (6) Place the photolithographic graphene with Se as a buffer layer in step (5) into a mild plasma reaction chamber and use O2 plasma to etch the exposed graphene channels. The area covered by photoresist will not change, and the Se on the channels will also be etched away by oxygen plasma to obtain the plasma-etched graphene.

[0061] (7) After washing away the photoresist from the etched graphene in step (6), anneal it at 275°C for 5 hours to remove the Se layer and obtain the O2 plasma-etched graphene channel without any photoresist residue.

[0062] (8) Transfer an In2Se3 thin layer onto the annealed graphene channel in step (7), deposit a gold electrode on the graphene, obtain a complete device, and test the output characteristic curve.

[0063] The etched graphene obtained in step (6) was observed under an optical microscope, and the results are as follows: Figure 2 As shown. The annealed graphene obtained in step (7) was observed under an optical microscope, and the results are as follows. Figure 3 As shown; the result obtained in step (8) is as follows Figure 4 As shown.

[0064] Example 2

[0065] This embodiment provides a method for preventing photoresist degradation during oxygen plasma etching of graphene based on an isolation layer. The process is as follows: Figure 1 The steps are as follows:

[0066] (1) First, place the silicon substrate in acetone and ultrasonically clean it for 4 minutes; then place the silicon substrate in ethanol and ultrasonically clean it for 4 minutes; then ultrasonically clean it in deionized water for 4 minutes; then dry it with a nitrogen gun; finally bake it on a heating platform at 290°C for 9 minutes.

[0067] (2) A few-layer graphene film was obtained by mechanical exfoliation and transferred to the surface of the cleaned substrate in step (1) by PDMS dry transfer technology to obtain a substrate with graphene.

[0068] (3) The photoresist is uniformly spin-coated onto the graphene-containing substrate prepared in step (2) at a spin speed of 580 rpm for 9 s and 2970 rpm for 25 s, followed by baking. The graphene is then placed on the stage of a maskless lithography machine, aligned with the channel area to be protected under a microscope, and masked, ensuring its width is 10 ± 0.5 μm. The remaining areas of the sample are exposed to ensure that the photoresist can be removed in the subsequent development step, thereby forming a photoresist mask protecting the channel area on the graphene sample, leaving the remaining areas bare.

[0069] (4) Place the developed graphene from step (3) into a vapor deposition machine and vapor deposit Se. The vacuum condition of the vapor deposition machine is 1×10⁻⁶. - 3 Below Pa, the evaporation rate used is The time was 30 minutes, and the thickness of the electrode material obtained was 50 nm. After washing away the photoresist, the trenches not covered by selenium were obtained. These trenches are the areas that need to be etched later. The remaining areas covered by selenium are the isolation layer that protects the graphene.

[0070] (5) The graphene after evaporation treatment in step (4) is spin-coated with photoresist again and baked. The trenches obtained after photolithography and development are exposed to the environment (Se is on the trenches), and the rest are isolated from the environment with photoresist.

[0071] (6) Place the photolithographic graphene with Se as a buffer layer in step (5) into a mild plasma reaction chamber and use O2 plasma to etch the exposed graphene channels. The area covered by photoresist will not change, and the Se on the channels will also be etched away by oxygen plasma to obtain the plasma-etched graphene.

[0072] (7) After washing away the photoresist from the etched graphene in step (6), anneal it at 250°C for 5 hours to remove the Se layer and obtain the O2 plasma-etched graphene channel without any photoresist residue.

[0073] Example 3

[0074] This embodiment provides a method for preventing photoresist degradation during oxygen plasma etching of graphene based on an isolation layer. The process is as follows: Figure 1 The steps are as follows:

[0075] (1) First, place the silicon substrate in acetone and ultrasonically clean it for 6 minutes; then place the silicon substrate in ethanol and ultrasonically clean it for 6 minutes; then ultrasonically clean it in deionized water for 6 minutes; then dry it with a nitrogen gun; finally bake it on a heating platform at 310°C for 10 minutes.

[0076] (2) A few-layer graphene film was obtained by mechanical exfoliation and transferred to the surface of the cleaned substrate in step (1) by PDMS dry transfer technology to obtain a substrate with graphene.

[0077] (3) The photoresist is uniformly spin-coated onto the graphene-containing substrate prepared in step (2) at a spin speed of 620 rpm for 10 s and 3030 rpm for 35 s, followed by baking. The graphene is then placed on the stage of a maskless lithography machine, aligned with the channel area to be protected under a microscope, and masked, ensuring its width is 10 ± 0.5 μm. The remaining areas of the sample are exposed to ensure that the photoresist can be removed in the subsequent development step, thereby forming a photoresist mask protecting the channel area on the graphene sample, leaving the remaining areas bare.

[0078] (4) Place the developed graphene from step (3) into a vapor deposition machine and vapor deposit Se. The vacuum condition of the vapor deposition machine is 1×10⁻⁶. - 3 Below Pa, the evaporation rate used is The time was 30 minutes, and the thickness of the electrode material obtained was 50 nm. After washing away the photoresist, the trenches not covered by selenium were obtained. These trenches are the areas that need to be etched later. The remaining areas covered by selenium are the isolation layer that protects the graphene.

[0079] (5) The graphene after evaporation treatment in step (4) is spin-coated with photoresist again and baked. The trenches obtained after photolithography and development are exposed to the environment (Se is on the trenches), and the rest are isolated from the environment with photoresist.

[0080] (6) Place the photolithographic graphene with Se as a buffer layer in step (5) into a mild plasma reaction chamber and use O2 plasma to etch the exposed graphene channels. The area covered by photoresist will not change, and the Se on the channels will also be etched away by oxygen plasma to obtain the plasma-etched graphene.

[0081] (7) After washing away the photoresist from the etched graphene in step (6), anneal it at 300°C for 6 hours to remove the Se layer and obtain the O2 plasma-etched graphene channel without any denatured photoresist residue.

[0082] Comparative Example 1

[0083] Referring to Example 1, the steps in the method for preparing the Se isolation layer in the example are omitted, that is, Se is not deposited before etching the trench. Everything else remains the same as in the example, resulting in graphene after the original etching method. Under a light microscope, it appears as follows: Figure 5 As shown in the image, without an insulating layer to protect the graphene, after oxygen plasma etching, the modified photoresist will remain in the etched channels, especially when the etching parameters are not accurately controlled during the etching process, it can cover the entire material, such as... Figure 5 As shown, the quality and performance of the final product are affected, but graphene with an isolation layer to prevent photoresist degradation during oxygen plasma etching can still be fabricated as shown. Figure 4 It is a complete device with good output characteristics.

[0084] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preventing photoresist degradation during oxygen plasma etching of graphene based on an isolation layer, characterized in that, Includes the following steps: S11: Transfer the graphene film onto the surface of the substrate to obtain a substrate with graphene. S12: Coat the substrate with graphene with photoresist, bake, and photolithographically develop to form a patterned photoresist mask; S13: Selenium is deposited at the pattern of the photoresist mask, and then the photoresist is washed away to form a sample; The sample contains trench I that is not covered by selenium and a selenium isolation layer that protects the graphene; S14: Coat the surface of the sample from step S13 with photoresist, bake, and photolithographically develop to form trench II, and obtain graphene after secondary development. S15: The graphene after secondary development is etched using oxygen plasma to obtain plasma-etched graphene. S16: After washing away the photoresist from the plasma-etched graphene, anneal it to obtain graphene channels based on an isolation layer to prevent photoresist degradation during oxygen plasma etching; in step S12, the photoresist coating method is: spin coating at 580-620 rpm for 9-10 s, and spin coating at 2970-3030 rpm for 25-35 s; the photolithography development method is: place the graphene on the maskless photolithography stage, align it with the trench I to be protected under a microscope, block it, and expose the remaining areas of the sample; in step S13, the selenium evaporation method is thermal evaporation; during thermal evaporation, the vacuum condition of the evaporation machine is 1×10 -4 At a pressure below Pa, the evaporation rate was 0.20-0.25 Å / s, the time was 30 min, and the resulting material thickness was 50 nm.

2. The method of claim 1, wherein the photoresist is not degraded during the etching of the graphene. In step S11, the substrate is a silicon-based substrate, which is ultrasonically cleaned in acetone, ethanol and water in sequence before transfer, then dried and baked.

3. The method of claim 1, wherein the photoresist is not degraded during the etching of the graphene. In step S11, the graphene film is transferred using the PDMS dry transfer method.

4. The method of claim 1, wherein the photoresist is not degraded during the etching of the graphene. The width of the groove I is 9.5-10.5 μm.

5. The method of claim 1, wherein the photoresist is not degraded during the etching of the graphene. In step S14, the developing solution used in photolithography is a mixture of an aqueous solution containing 25 wt% tetramethylammonium hydroxide and water, with a volume ratio of 25:

3.

6. The method for preventing photoresist degradation during oxygen plasma etching of graphene based on an isolation layer as described in claim 1, characterized in that, In step S16, the annealing temperature is 250-300℃ and the time is 5-6 hours.

7. A graphene channel prepared by the method described in any one of claims 1-6, based on an isolation layer to prevent photoresist degradation during oxygen plasma etching of graphene.

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