Direct synthesis of graphene on silicon oxide by low temperature plasma enhanced chemical vapor deposition

Abstract

Direct graphene growth on silicon with a native oxide using plasma enhanced chemical vapour deposition at low temperatures [550 °C–650 °C] is demonstrated for the first time. It is shown that the fine-tuning of a two-step synthesis with gas mixtures C₂H₂/H₂ yields monolayer and few layer graphene films with a controllable domain size from 50 nm to more than 300 nm and the sheet resistance ranging from 8 kΩ sq⁻¹ to less than 1.8 kΩ sq⁻¹. Differences are understood in terms of the interaction of the plasma species – chiefly atomic H – with the deposited graphene and the native oxide layer. The proposed low temperature direct synthesis on an insulating substrate does not require any transfer processes and improves the compatibility with the current industrial processes.