Capacitance-voltage measurements on metal-SiO2-boron-doped homoepitaxial diamond

A metal-SiO2-boron-doped homoepitaxial diamond MTS structure was fabricated on (100) substrates of type Ib synthetic diamond. Capacitance-voltage characteristics were measured for various boron concentrations and it was concluded that when the impurity concentration increased, an impurity band was formed 0.35 eV above the valence band which was composed of the excited state of the boron impurity and its phonon sideband. When the impurity concentration increased, the capacitance of the MIS structure decreased and the equilibrium density of holes in the films also decreased. With this Impurity band the film works as a metal electrode. (C) 1997 Elsevier Science S.A.