INVESTIGATION OF THE ELECTRONIC-STRUCTURE OF THIN DIAMOND FILMS BY PHOTOELECTRON-SPECTROSCOPY

We report an in-situ study of the electronic structure of thin diamond films using X-ray photoelectron (XPS) and ultraviolet photoelectron (UPS) spectroscopies. The films are grown by a standard hot-filament technique on a heated silicon substrate in a dilute mixture of methane in hydrogen. The photoemission valence-band spectra of the diamond films are compared to those of single-crystal diamond as well as to calculated density of states. Measurements performed on low deposition time films make possible the in-situ probing of the initial growth of the film on the substrate, and reveal core-level line shifts characteristic of a reactive interface.