Electrical properties of graphite/homoepitaxial diamond contact

Abstract We have studied the electrical properties of the graphitic electrodes formed in sulfur- and boron-doped homoepitaxial diamond films in order to make reliable ohmic contacts in diamond-based electronic devices. Sulfur-doped diamond films were achieved by sulfur ion implantation in undoped homoepitaxial diamond films. Boron-doped homoepitaxial diamond films were synthesized by gas-phase doping of boron during the chemical vapor deposition growth. The graphitization of diamond by Ar ion implantation was utilized for the graphitic electrodes. The electrical properties of graphite/diamond contacts were investigated by using the current–voltage measurement. The specific contact resistances were characterized by applying the linear transmission line model (TLM) and circular TLM extrapolation methods, and were determined to be 5.2×103 and 1.18 Ω·cm2, respectively.