ELECTRIC PROPERTIES OF METAL DIAMOND INTERFACES UTILIZING HYDROGEN-TERMINATED SURFACES OF HOMOEPITAXIAL DIAMONDS

As-grown homoepitaxial diamond surfaces fabricated by chemical vapor d eposition are terminated by hydrogen, and are expected to have a low d ensity of surface states. On such diamond surfaces, high-quality Schot tky contacts have been obtained utilizing metals with low electronegat ivities, such as Al or Pb. The ideality factors of those point contact s to diamond are less than 1.1, which is the nearest value to unity ev er reported in diamonds. Quantitative measurements of Schottky barrier heights at various metal contacts have also been performed. A strong correlation between the barrier heights and the metal electronegativit ies is observed. Even an ohmic property is obtained when metals with h igher electronegativities were used. The eff ect of Fermi level pinnin g is reduced at the interfaces between metals and hydrogen-terminated diamonds.