In situ studies of Al2O3 and HfO2 dielectrics on graphite

Deposition of Al2O3 and HfO2 dielectrics on graphite is studied as a route to the formation of a high-κ dielectric on graphene. Electron beam evaporation of metal Al and Hf is followed by a separate oxidation step. Reactive e-beam deposition of HfO2 by introduction of O2 to the deposition chamber is also demonstrated as an alternative to the two-step metal deposition and oxidation approach. We employ in situ x-ray photoelectron spectroscopy to study reactions between the substrate and deposited film and ex situ atomic force microscopy to examine the dielectric film morphology.