Synthesis of Large-scale Patterned Graphene on SiC via Si Nitridation for Carbon Condensation
Hsu-Sheng Tsai1*, Jenq-Horng Liang2, Henry Medina1, Yun-Lun Chueh1
1Material Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan
2Nuclear Engineering and Science, National Tsing Hua University, Hsinchu, Taiwan
* presenting author:蔡勖升,
Graphene, has shown outstanding physical properties being a promising candidate material for a variety of electronic applications. Up to date, there are several issues related to the material synthesis and device fabrication, which need to be overcome. Despite that graphene film synthesized by chemical vapor deposition can grow large area with relatively low defects; the required transfer process creates wrinkles and polymer residues that greatly reduce its performance for different device applications. Graphene synthesized on Silicon-Carbide (SiC) has shown an outstanding mobility being successfully used to develop ultra-high frequency transistors; however, this fabrication method is limited due to the use of costly equipment that can reach temperatures over 1400C under ultra-high vacuum (~10-7Torr). Here we show a feasible novel approach to synthesize graphene on SiC substrate only requiring equipment that is commonly used in semiconductor processing industry. In this work, we used plasma treatment followed by annealing process in order to obtain large-scale graphene films from bulk SiC. After exposure of N2 plasma, the N2 annealing process promotes nitrogen ions to react with Si and simultaneously condense C around the surface of the SiC. Eventually, a uniform large-scale graphene film on SiC wafer will be achieved. The XPS results indicate that the formation of a silicon nitride layer. The Raman analysis shows typical spectra of few layer graphene. Furthermore, graphene can be patterned by selectively exposing the SiC to N2 plasma. The nitridation process, is a feasible process that enables large scale and uniform synthesis of patterned graphene for the development of graphene electronics.

Keywords: graphene, plasma, nitridation