CAPACITANCE-VOLTAGE MEASUREMENTS ON METAL-SIO2-BORON-DOPED HOMOEPITAXIAL DIAMOND

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