Secondary electron emission measurements on synthetic diamond films

摘要

During the electron irradiation of synthetic diamond films, three successive regimes are encountered as a function of the electron dose: (1) a reduction of the downward band bending of energy levels at the sample surface because an excess ofsecondary electrons leaves the sample; (2) the creation of an internal electric field in which secondary electrons drift to the surface, leading to an appreciable increase in the secondary emission and to a linear relation between the primary electronenergy and the secondary electron yield; and (3) the desorption of hydrogen terminating the carbon surface bonds. The secondary emission thus decreases to very low values. The rate of decrease of secondary emission is similar for C:H- andC:H:Ba-terminated diamond surfaces.