Steam-assisted low-dimensional semiconductor organic ligand removal method

Abstract

The invention discloses a steam-assisted low-dimensional semiconductor organic ligand removal method, which belongs to the field of two-dimensional semiconductor device preparation, and is characterized in that a specific organic solvent is heated in a closed environment, so that solvent steam slowly acts on the surface of a two-dimensional semiconductor film which is formed by transfer; mild removal of surface residues and interface performance optimization are achieved, and the problem that a film is damaged due to traditional liquid phase treatment is solved. According to the method, surface adsorption pollutants influencing carrier transmission can be effectively removed, the completeness of the film can be kept without wrinkles, and meanwhile, due to the fact that the processing temperature is low, the compatibility problem in the technological process is solved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor material cleaning, and in particular to a steam-assisted method for removing low-dimensional semiconductor organic ligands. Background Art

[0002] Two-dimensional semiconductor materials, due to their unique physical properties and excellent electrical and optical performance, hold broad application prospects in electronics, optoelectronics, and sensors. Surface engineering is a key step in the fabrication of two-dimensional semiconductor devices, influencing their ultimate performance. On the one hand, surface contaminants are inevitably introduced during the preparation and transfer of two-dimensional materials; on the other hand, these surface residues can severely impair carrier transport within the two-dimensional materials.

[0003] Currently, there are two main methods for treating surface contaminants in two-dimensional semiconductor thin films: direct cleaning by immersion in organic solvents; and high-temperature annealing. However, these traditional methods have significant drawbacks. While liquid immersion can remove some residues, it often results in damage, wrinkling, or delamination of the 2D material. High-temperature annealing can cause chemical degradation of the 2D material, lattice deformation, or adverse reactions with the substrate.

[0004] Especially for environmentally sensitive two-dimensional materials such as transition metal dichalcogenides (TMDCs), traditional processing methods often struggle to effectively remove surface contaminants while maintaining the integrity of the material. The presence of these surface contaminants can significantly reduce carrier mobility and increase contact resistance, thereby affecting device performance and stability.

[0005] Therefore, designing a treatment method that can effectively remove residues from the surface of two-dimensional semiconductor thin films while maintaining the integrity of the films is a current research problem. To address the above issues, the following proposes a solution. Summary of the Invention

[0006] The present invention aims to provide a steam-assisted low-dimensional semiconductor organic ligand removal method, which has the advantage of being able to gently remove surface residues while maintaining the integrity of the film.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions: A steam-assisted method for removing organic ligands from low-dimensional semiconductors comprises the following steps: S1: forming a two-dimensional semiconductor material on a substrate by transfer or direct growth; S2: placing the two-dimensional semiconductor material film in a sealed container; S3: placing an organic solvent in the sealed container and heating the organic solvent to evaporate it; S4: controlling the temperature and the concentration of the gaseous organic solvent in the sealed container so that the organic solvent vapor slowly acts on the surface of the two-dimensional semiconductor material film to remove residues on the film surface; S5: After the treatment is completed, the two-dimensional semiconductor material film is removed to obtain a two-dimensional semiconductor material film with reduced surface pollutant content and no obvious damage.

[0008] Preferably, the two-dimensional semiconductor material forming method in step S1 includes one or more of mechanical stripping, chemical vapor deposition, wet chemical synthesis or dry transfer.

[0009] Preferably, the organic solvent in step S3 is selected from one or more of n-hexane, isopropanol, acetone, toluene or ethanol.

[0010] Preferably, the temperature in the sealed container in step S4 is 20-150°C, preferably 30-100°C.

[0011] Preferably, the gas phase treatment time in step S4 is 5-180 minutes, preferably 15-60 minutes.

[0012] Preferably, the two-dimensional semiconductor material film includes one or more of graphene, transition metal dichalcogenides, black phosphorus, h-BN or MXene.

[0013] The beneficial effects of the present invention are: 1. The present invention uses a vapor-phase organic solvent to treat a two-dimensional semiconductor material thin film. The treatment process is gentle and controllable, avoiding mechanical damage to the film caused by liquid immersion and effectively solving the problem of film breakage. 2. By controlling the temperature and concentration of the vapor-phase organic solvent, the surface cleaning process can be precisely controlled, making it compatible with the processing technology of common functional layers; 3. The vapor phase treatment can act evenly on the film surface, and with the synergistic effect of trace condensation droplets, it not only ensures the full removal of surface residues but also maintains the structural integrity of the film. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of a vapor phase surface treatment device according to an embodiment.

[0015] Figure 2 Comparison of optical microscope images of copper-based graphene transferred to the surface of SiO2 / Si substrate before and after vapor phase treatment in Example. DETAILED DESCRIPTION

[0016] The following description is only a preferred embodiment of the present invention, and the protection scope is not limited to this embodiment. All technical solutions under the concept of the present invention should fall within the protection scope of the present invention.

[0017] Example 1 (1) Preparation of two-dimensional semiconductor material films: The graphene film grown by chemical vapor deposition was transferred onto a Si / SiO2 (300nm) substrate using a wet transfer technique on a copper-based substrate to form a two-dimensional semiconductor material film.

[0018] (2) Vapor phase surface treatment: The prepared two-dimensional semiconductor material film was fixed upside down on the top cover of a glass sealed container, 15 mL of isopropanol was placed at the bottom of the container, and the entire container was placed on a constant temperature heating table at 40°C. It was heated for 30 minutes so that the isopropanol vapor filled the container and acted on the surface of the two-dimensional semiconductor material film.

[0019] (3) Subsequent processing: After the second step, the film was removed and placed in a nitrogen environment for 30 minutes, and then placed in a vacuum environment (0.1 mTorr) for 10 minutes to remove the residual solvent.

[0020] Example 2 Compared with Example 1, the difference is: (1) The single-layer or few-layer MoS2 flakes obtained by mechanical exfoliation were used.

[0021] (2) Acetone was used instead of isopropyl alcohol during the gas phase treatment, the treatment temperature was 60°C, and the treatment time was 20 minutes.

[0022] Example 3 Compared with Example 1, the difference is: (1) The two-dimensional semiconductor material is WS2 grown by chemical vapor deposition.

[0023] The above embodiments show that the vapor phase surface treatment method provided by the present invention can effectively remove surface residues while maintaining the integrity of the two-dimensional semiconductor material film, providing a new technical path for the preparation of high-performance two-dimensional semiconductor devices.

[0024] The foregoing is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It will be apparent to those skilled in the art that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

[0025] The specific embodiments described above further illustrate the technical problems, technical solutions and beneficial effects solved by the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A steam-assisted method for removing low-dimensional semiconductor organic ligands, characterized in that: The following steps are involved: S1: forming a two-dimensional semiconductor material on a substrate by transfer or direct growth; S2: placing the two-dimensional semiconductor material film in a sealed container; S3: placing an organic solvent in the sealed container and heating the organic solvent to evaporate it; S4: controlling the temperature and the concentration of the gaseous organic solvent in the sealed container so that the organic solvent vapor slowly acts on the surface of the two-dimensional semiconductor material film to remove residues on the film surface; S5: After the treatment is completed, the two-dimensional semiconductor material film is removed to obtain a two-dimensional semiconductor material film with reduced surface pollutant content and no obvious damage.

2. The steam-assisted low-dimensional semiconductor organic ligand removal method according to claim 1, characterized in that: The two-dimensional semiconductor material forming method in step S1 includes one or more of mechanical stripping, chemical vapor deposition, wet chemical synthesis or dry transfer.

3. The steam-assisted low-dimensional semiconductor organic ligand removal method according to claim 1, characterized in that: The organic solvent in step S3 is selected from one or more of n-hexane, isopropanol, acetone, toluene or ethanol.

4. The steam-assisted low-dimensional semiconductor organic ligand removal method according to claim 1, characterized in that: In step S4, the temperature in the sealed container is 20-150°C, preferably 30-100°C.

5. The steam-assisted low-dimensional semiconductor organic ligand removal method according to claim 1, characterized in that: The gas phase treatment time in step S4 is 5-180 minutes, preferably 15-60 minutes.

6. The steam-assisted low-dimensional semiconductor organic ligand removal method according to claim 1, characterized in that: The two-dimensional semiconductor material film includes one or more of graphene, transition metal dichalcogenides, black phosphorus, h-BN or MXene.

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