Plasma-enhanced chemical vapor deposition of graphene optimized by pressure

Abstract

Fast growth of graphene on non-catalytic substrates by plasma-enhanced chemical vapor deposition (PECVD) usually results in poor crystalline quality and sometimes is accompanied by the formation of amorphous carbon. In this study, we slow down the graphene growth on quartz substrates by elevating pressure in a PECVD setup. The lower growth rate is caused by slower diffusion of gaseous species in the plasma to the substrate surface at higher pressure. The slower growth at high-temperature is crucial for larger critical nucleus size, higher nucleation barrier, and better electrical properties. Better graphene quality under higher pressure growth is verified by Raman spectroscopy. A hole mobility up to 89.6 cm2·V−1·s−1 is acquired with a growth rate of 1.34 nm h−1 at 950 °C, 1.2 Torr.