Method for growing graphene film on silicon surface

Abstract

The invention relates to a method for growing a graphene film on a silicon surface. The method comprises the following steps: S1, providing a silicon substrate; and S2, generating an active carbon atom concentration enhancement field through the temperature gradient field, introducing a carbon source gas, and carrying out CVD growth on the silicon substrate to obtain the graphene film with the thickness of 3-5 nm. According to the method for growing the graphene film on the silicon surface, graphene is directly grown on the silicon surface in a large area through CVD by means of an active carbon atom concentration enhancement field, the limitation that graphene growth needs a metal catalysis substrate and various problems caused by graphene transfer are solved, and the graphene film with a certain thickness is obtained.

Description

Technical Field

[0001] The present invention relates to carbon materials, and more particularly to a method for growing a graphene film on a silicon surface. Background Art

[0002] Graphene is a new material composed of tightly packed, sp²-hybridized carbon atoms forming a single-layer, two-dimensional honeycomb lattice. This unique crystal structure enables ultra-high carrier mobility, making it considered a key candidate for channel materials in the post-Moore era. Currently, large-area graphene films grown using CVD methods primarily utilize metal as a catalytic substrate; direct growth on silicon substrates is not feasible. However, its application in microelectronics requires a silicon-based substrate, necessitating the transfer of graphene from a metal substrate to a silicon-based substrate using a transfer process. This transfer process, however, can lead to graphene breakage, interfacial contamination, and increased costs, severely limiting its application in microelectronics. While there have been occasional reports of graphene growth on silicon surfaces, the resulting graphene is of low quality and exhibits numerous defects, making it unsuitable for use in integrated circuits. Summary of the Invention

[0003] In order to solve the above problems in the prior art such as graphene damage caused by transfer, the present invention provides a method for growing a graphene film on a silicon surface.

[0004] According to the method for growing a graphene film on a silicon surface of the present invention, the method comprises the following steps: S1, providing a silicon substrate; S2, generating an active carbon atom concentration enhancement field through a temperature gradient field, introducing a carbon source gas, and growing a graphene film with a thickness of 3nm-5nm on the silicon substrate by CVD.

[0005] In a preferred embodiment, the silicon substrate is a silicon wafer without an oxide layer.

[0006] In a preferred embodiment, the temperature gradient of the temperature gradient field ranges from 2×10 3 °C / m to 5×10 3 °C / m.

[0007] In a preferred embodiment, the CVD growth temperature is 500°C-600°C.

[0008] In a preferred embodiment, the carbon source gas is methane, acetylene and / or ethyne.

[0009] In a preferred embodiment, auxiliary gas is introduced during CVD growth.

[0010] In a preferred embodiment, the auxiliary gas is hydrogen and argon.

[0011] The method for growing graphene films on silicon surfaces according to the present invention utilizes an activated carbon atom concentration enhancement field to directly grow graphene on a large surface area via CVD. This overcomes the limitations of graphene growth requiring a metal catalytic substrate and various issues associated with graphene transfer, achieving compatibility with existing integrated circuit processes. The method enables the preparation of graphene films with controllable thickness, laying the foundation for their application in integrated circuits and promoting the application of graphene in the field of microelectronics. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a photo of the graphene film according to Example 1 of the present invention.

[0013] Figure 2 This is an optical microscope image of the graphene film of Example 1.

[0014] Figure 3 This is a scanning electron microscope (SEM) image of the graphene film of Example 1.

[0015] Figure 4 This is an atomic force microscope (AFM) image of the graphene film of Example 1.

[0016] Figure 5 This is a Raman graph of the graphene film of Example 1. DETAILED DESCRIPTION

[0017] The preferred embodiments of the present invention are given below in conjunction with the accompanying drawings and described in detail.

[0018] The method for growing a graphene film on a silicon surface according to the present invention first includes providing a silicon substrate.

[0019] In a preferred embodiment, the silicon substrate is a silicon wafer without an oxide layer.

[0020] The method for growing a graphene film on a silicon surface according to the present invention then includes generating an active carbon atom concentration enhancement field through a temperature gradient field, introducing a carbon source gas, and growing a graphene film with a thickness of 3nm-5nm on a silicon substrate by CVD.

[0021] In the present invention, graphene with controllable thickness can be directly grown on the silicon surface by means of an activated carbon atom concentration enhancement field to obtain a high-quality graphene film, thereby solving the problem in the prior art that it is difficult to grow a high-quality graphene film with controllable thickness on the silicon surface.

[0022] In a preferred embodiment, the temperature gradient of the temperature gradient field ranges from 2×10 3 ° C. / m to 5×10 3 ° C. / m. In a preferred embodiment, the temperature gradient of the temperature gradient field ranges from 4×10 3 ° C. / m to 5×10 3 ° C. / m.

[0023] In a preferred embodiment, the CVD growth temperature is 500° C.-600° C. In a preferred embodiment, the CVD growth temperature is 500° C.

[0024] In a preferred embodiment, the carbon source gas is methane, ethylene and / or acetylene. In a preferred embodiment, the carbon source gas is methane.

[0025] In a preferred embodiment, an auxiliary gas is introduced during the CVD growth, and in a preferred embodiment, the auxiliary gas is hydrogen and argon.

[0026] In a preferred embodiment, the CVD growth time is 20 minutes to 40 minutes. In a preferred embodiment, the CVD growth time is 30 minutes.

[0027] In a preferred embodiment, the thickness of the graphene film is 4 nm-5 nm.

[0028] Example 1

[0029] A silicon wafer with a thickness of 600μm was selected, the growth temperature was set to 500℃, methane gas was introduced, the temperature gradient was 2×10³℃ / m, and the growth time was 30 minutes to obtain a graphene film with a thickness of 3nm.

[0030] like Figure 1-Figure 4 As shown in FIG, the surface of the graphene film obtained according to this embodiment is smooth and flat, and the thickness is uniform. Figure 5 As shown in FIG. 1 , the energy spectrum of the graphene film obtained according to this embodiment shows that the Raman defect peak is relatively low, indicating that the graphene is of high quality.

[0031] Example 2

[0032] A 600μm-thick silicon wafer was selected, the growth temperature was set to 500°C, methane gas was introduced, and the temperature gradient was 5×10³°C / m. A 30-minute growth period yielded a 3.5nm-thick graphene film. Compared to Example 1, the temperature gradient was reduced to 5×10³°C / m.

[0033] Example 3

[0034] A silicon wafer with a thickness of 600μm was selected, the growth temperature was set to 600℃, methane, hydrogen and argon auxiliary gases were introduced, the temperature gradient was 2×10³℃ / m, and the growth time was 30 minutes to obtain a graphene film with a thickness of 4nm.

[0035] Example 4

[0036] A 600μm-thick silicon wafer was selected, the growth temperature was set to 600°C, methane gas was introduced, and the temperature gradient was 5×10³°C / m. The growth time was 30 minutes, resulting in a 35nm-thick graphene film. Compared to Example 1, the temperature gradient was changed to 5×10³°C / m, and the growth temperature was changed to 600°C.

[0037] Comparative Example 1

[0038] A 600μm thick silicon wafer was selected, the growth temperature was set to 500°C, methane gas was introduced, the temperature gradient was 1×10³°C / m, and the growth time was 30 minutes. The resulting sample was free of graphene. Compared to Example 1, the temperature gradient was changed to 1×10³°C / m.

[0039] Comparative Example 2

[0040] A 600μm thick silicon wafer was selected, the growth temperature was set to 450°C, methane gas was introduced, the temperature gradient was 2×10³°C / m, and the growth time was 30 minutes to obtain a sample without graphene. Compared with Example 1, the growth temperature was changed to 450°C.

[0041] Comparative Example 3

[0042] A 600μm thick silicon wafer was selected, the growth temperature was set to 620°C, methane gas was introduced, the temperature gradient was 2×10³°C / m, and the growth time was 30 minutes. The sample obtained was amorphous carbon. Compared with Example 1, the growth temperature was changed to 620°C.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Various modifications are possible. In other words, any simple, equivalent changes and modifications made in accordance with the claims and description of the present invention are within the scope of protection of the patent claims. Anything not fully described in this invention constitutes conventional technology.

Claims

1. A method for growing a graphene film on a silicon surface, characterized in that: The method comprises the following steps: S1, provides silicon substrate; S2, generating an active carbon atom concentration enhancement field through a temperature gradient field, introducing a carbon source gas, and growing a graphene film with a thickness of 3nm-5nm on a silicon substrate by CVD.

2. The method according to claim 1, characterized in that The silicon substrate is a silicon wafer without an oxide layer.

3. The method according to claim 1, characterized in that The temperature gradient range of the temperature gradient field is 2×103℃ / m-5×103℃ / m.

4. The method according to claim 3, characterized in that The temperature gradient range of the temperature gradient field is 4×103℃ / m-5×103℃ / m.

5. The method according to claim 1, wherein The CVD growth temperature is 500℃-600℃.

6. The method according to claim 1, characterized in that The carbon source gas is methane, ethylene and / or acetylene.

7. The method according to claim 1, characterized in that Auxiliary gases are introduced during CVD growth.

8. The method according to claim 7, characterized in that The auxiliary gases are hydrogen and argon.

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