Gap-state measurements on diamond-like carbon films

Abstract

A high frequency capacitance-voltage method is used to measure the electronic gap-state density in diamond-like carbon (DLC) films. The gap-state density is derived from the analysis of high frequency capacitance-voltage characteristics of DLC on crystalline silicon (c-Si) heterojunctions. Near the Fermi level the gap-state density in the DLC thin film is obtained of the order 1016 cm-3 eV-1. Furthermore, the energy-band diagram of a DLC/c-Si heterojunction is evaluated, and the work function of DLC is derived to be 3.6 eV.