CVD Growth Of Graphene On Patterned Metal Film Substrate

Graphene has triggered unprecedented research excitement due to its excellent electric, thermal, mechanical and optical properties. Large-area and high-quality graphene film is often synthetized by CVD technique with Cu foils and Ni films as catalysts, and then transferred onto target substrate for device applications. However, conventional transfer process and graphene-patterned process are complicated and destructive, during which the mechanical properties of single layer graphene(SLG) may be damaged. Defects of graphene induced in those procedures are harmful for unique properties of graphene in device applications. In this regard, In-situ growth of graphene on pre-patterned metal substrate is investigated in this paper as a promising method, which can be directly used to construct devices without any extra steps.In this paper, we investigate CVD growth of graphene on different pre-patterned metal film substrates, we use lithography, sputtering and lift-off processes to fabricate pre-patterned Cu film, Ni film and Cu /Ni double layer film on oxidized silicon substrates as catalyst, and then fulfill selective graphene growth by CVD technique using these three different pre-patterned metal films simultaneously. Then, by changing the CVD growth parameters(pressure, atmosphere, etc.) to explore the influence of different growth parameters on the quality of graphene growth, through which we can choose suitable CVD growth parameters to grow high-quality graphene. Graphene quality and metal film substrates conditions are characterized by Laman Spectrum, AFM,SEM, XRD, etc.We investigate the differences of graphene growth between these three kinds of substrate in this paper. It is found that the Cu /Ni double layer film has the largest grain size and the smoothest surface under the same growth parameters, which is favorable for non defect large-area graphene growth. Subsequently, we study graphene growth mechanism on the Cu /Ni double layer film and find that the underneath nickel film act as “buffer layer” which can improve the above copper film quality during sputtering process. Finally, we immerse graphene/metal composite structure into the 0.5mol/L ammonium persulfate solution for corrosion, it is demonstrated that the corrosion rate of metal base covered with graphene is significantly slower than the bare metal base, which indicates that graphene can effectively protect the base metal from corrosion.