부산대학교 도서관

The oxide/semiconductor structure is key to controlling current in electronic devices and HfO 2 is a common gate material in conventional electronic devices due to its favorable dielectric properties. Graphene devices also require insulating gates. We demonstrate a unique direct growth approach to obtain the bottom gate structure (graphene/HfO 2 /n-SiC). The present approach involves transfer of graphene grown by chemical vapor deposition (CVD) on Cu to oxidized Si wafers, a complex process prone to low yield and reduced performance. Furthermore, HfO 2 is preferred to SiO 2 because of its superior properties. The proposed concept consists of the direct deposition of graphene by solid carbon molecular beam epitaxy on Hf metal coated n-type SiC, followed by oxygen intercalation to form HfO 2 . The oxygen intercalation will then convert the underlying Hf into HfO 2 due to the strong affinity of Hf with oxygen. We identify the graphene/HfO 2 formation by Raman, X-ray photoelectron spectroscopy (XPS), Low energy electron diffraction (LEED), Low energy electron microscopy (LEEM) and electrical properties including Hall mobility and leakage current measurement. [ABSTRACT FROM AUTHOR]