In situ photoemission spectroscopy study on formation of HfO_2 dielectrics on epitaxial graphene on SiC substrate

摘要

High quality HfO_2 dielectrics have been grown on epitaxial graphene on 4H-SiC substrates and have been studied by using in situ x-ray photoemission spectroscopy. The in situ thermal treatment shows that the HfO_2/graphene/4H-SiC heterojunctions have good thermal stability up to 650 ℃. A shift of core-level spectra from graphene layer implies that charge transfer takes place at the interface. The high thermal stability and sufficient barrier heights between HfO_2 and graphene indicate that high-k dielectric grown on graphene is very promising for the development of graphene-based electronic devices.