Improvement of carrier mobility of top-gated SiC epitaxial graphene transistors using a PVA dielectric buffer layer

摘要

The effects of treatment with polyvinyl alcohol (PVA) and a dielectric film of HfO_ 2 on the properties of SiC based epitaxial graphene have been explored and analyzed. We have characterized the carrier mobility of graphene on Si-face and C-face SiC with a layer of HfO_ 2, with or without an initial PVA treatment on the device active layer. Epitaxial graphene grown on the C-face displays a higher mobility than a film grown on the silicon face. Also, the mobility in the presence of the PVA treatment with HfO_ 2 dielectric layer has been improved, compared with the mobility after deposition of only gate dielectric: 20% in C-face graphene and 90% in Si-face graphene. This is a major improvement over the degradation normally observed with dielectric/graphene systems.