High growth rate chemical vapor deposition of graphene under low pressure by RF plasma assistance

High throughput synthesis of atomic layer graphene membrane by chemical vapor deposition (CVD) is one of key technologies to establish industrial applications. Here we report the details of the initial stage of graphene growth on copper substrate by radio frequency (RF) plasma-assisted CVD under low pressure and compare the nucleation rate and the growth rate with conventional thermal CVD. Two-dimensional growth rate of graphene by plasma-assisted CVD is 100 and 1000 times larger than that of thermal CVD at 950 °C and at 750 °C, respectively. It is found that graphene growth is governed by the diffusion of active carbon species on the copper surface with a very low activation energy of 0.4 eV at low-temperature(≦ 850 °C) and low pressure. The high growth rate of plasma-assisted CVD of graphene is discussed.