Graphene growth on non-metallic substrates by Chemical Vapor Deposition

The electrical properties of graphene on dielectric substrates have many applications. Graphene is usually grown on metallic substrates then transferred onto dielectric substrates as necessary. However, to obtain graphene directly on non-metallic substrates is still challenging. In this work, we show the direct synthesis of graphene on SiO₂/Si and SiC by hot-filament chemical vapor deposition. The graphene deposition was conducted at low pressures with a mixture methane in hydrogen and a substrate temperature 900°C followed by abrupt cooling to room temperature. A thin strip of copper layer was sputtered in the middle of the SiO₂/Si substrates as a catalytic material. For the SiC substrate, a hydrofluoric acid treatment was used before graphene deposition. The structural properties of the graphene films were analyzed using Raman Spectroscopy, Atomic Force Microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Raman mapping and AFM measurements indicate the growth of few-layer graphene films in all cases. X-ray photoelectron spectroscopy confirmed the presence of graphene deposition on SiO₂/Si and SiC substrates. The results show that the availability of copper vapors from the thin copper strip enables the growth of graphene in all surfaces of the non-metallic substrates.