High-conductance, low-leakage diamond Schottky diodes

Schottky diodes formed of Al, Au, and Hg on diamond have been characterized as a function of plasma treatment and thermal annealing. Plasmas formed from N2O, H2, or O2 result in high surface leakage, while plasmas formed from N2 or from CF4 with 8.5% O2 result in total leakage <1000 e/s. Annealing the diamond at 660 °C before the Schottky diode is fabricated causes an increase in the forward conductance with n-factors approaching one. This annealing removes a compensated subsurface layer that often occurs in diamond during normal processing.