Field Effect and Electrical Conduction Mechanism in Discontinuous Thin Metal Films

A study has been made of the electrical conduction mechanism in discontinuous thin metal films. The high current density and field-dependent conductivity found in these films are shown to be due to the presence of trapping centers between metal aggregates. The charge carriers are created both by thermal excitation and by field injection. The charge transport mechanism is basically by tunneling via the trapping centers. The current I in a thin discontinuous metal film and the applied voltage V are shown to obey a simple relationship I = AV+BVn, where A and B are functions of temperature and n is a number equal to or greater than 2. Experimentally observed I–V characteristics of thin discontinuous chromium films over a wide temperature range are shown to be in good agreement with the theoretical model.