Observation of quantum-Hall effect in gated epitaxial graphene grown on SiC (0001)

Abstract

Epitaxialgraphene films examined were formed on the Si-face of semi-insulating 4H-SiC substrates by a high temperature sublimation process. A high- k gate stack on the epitaxialgraphene was realized by inserting a fully oxidized nanometer thin aluminumfilm as a seeding layer, followed by an atomic-layer deposition process. The electrical properties of epitaxialgraphene films are retained after gate stack formation without significant degradation. At low temperatures, the quantum-Hall effect in Hall resistance is observed along with pronounced Shubnikov–de Haas oscillations in diagonal magnetoresistance of gated epitaxialgraphene on SiC (0001).