Direct graphene growth on transitional metal with solid carbon source and its converting into graphene/transitional metal oxide heterostructure

Jeongho B Park (1) , Tyson C Back (2) , Steven B Fairchild (1) , William C Mitchel (1) , Said Elhamri (2) , John B Boeckl (1) , Dominique C Martinotti (3) , Ludovic C Douillard (3) , Patrick C Soukiassian (4, 5)

1 AFRL - Air Force Research Laboratory
2 University of Dayton
3 LEPO - Laboratoire d'Electronique et nanoPhotonique Organique
4 University Paris-Sud
5 LENSIS - Laboratoire d'Etude des NanoStructures et Imagerie de Surface

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.

Domains: Physics [physics]

Jeongho B Park, Tyson C Back, Steven B Fairchild, William C Mitchel, Said Elhamri, et al.. Direct graphene growth on transitional metal with solid carbon source and its converting into graphene/transitional metal oxide heterostructure. Carbon, 2017, 116, pp.303-309. ⟨10.1016/j.carbon.2017.01.072⟩. ⟨cea-01520061⟩