Low-leakage p-type diamond Schottky diodes prepared using vacuum ultraviolet light/ozone treatment

Room-temperature fabrication of Schottky diodes was demonstrated for p-type boron-doped diamond. This fabrication method’s key technique is selective modification of surface termination from monohydride into oxygen groups using vacuum ultraviolet light irradiation in oxygen. The Au contacts, formed on the hydrogen-terminated surface, maintained Ohmic properties after this selective surface oxidation. The Au contacts then deposited on the oxidized surface, imparting Schottky properties. The lateral-type diodes comprising Au Schottky contacts and Au Ohmic contacts showed blocking voltage higher than 1 kV without electrode guarding. The leakage current at 1 kV was as low as 30 pA.