Ohmic contact of Pt/Au on hydrogen-terminated single crystal diamond

In this study, contact properties of platinum/gold (Pt/Au) on the surface of hydrogen-terminated single crystal diamond (H-SCD) were studied with several treatment conditions. The electrodes of Pt (20 nm)/Au (100 nm) were deposited on H-SCD surface by electron beam evaporation technique. Then, the specific contact resistance (ρ_c) of the as-fabricated sample was measured by the circular transmission line model, which showed good ohmic properties with the value of 5.65 × 10-4 Ω·cm². To identify the thermal stability of Pt/Au/H-SCD, the sample was annealed in hydrogen ambient from 200 to 700 °C for 20 min at each temperature. As the temperature increased, ρc demonstrated better thermal stability. In addition, the barrier height was evaluated to be -0.67 ± 0.12 eV by X-ray photoelectron spectroscopy (XPS) technique.