High temperature stability of chemically vapour deposited diamond diodes

The wide band gap of diamond (5.5 eV) suggests that high temperature electronic device operation will be achievable. The emergence of polycrystalline thin film diamond, grown by chemical vapour deposition methods, has made this prospect commercially interesting. Among the primary requirements for the realization of such a device are ohmic and Schottky contacts which display long-term stability at elevated temperatures. In this paper a widely used ohmic metallization scheme, TiAu, is contrasted with a trilevel contact, TiAgAu. Given the morphology and doping level of the diamond film used, TiAgAu coupled with an Al Schottky barrier offers stable diode characteristics following operation at 400 °C.