1/f Noise from Vacuum-Cleaned Silicon

The removal of the adsorbed gases and the surface oxide on single-crystal, 100 Ω-cm silicon filaments by ion bombardment and annealing does not have an appreciable effect on either the magnitude or the frequency dependence of the 1/f noise from the filament. Since the slow surface states are commonly associated with gases adsorbed on the oxide, charge transfer between these states and the bulk cannot be the primary source of 1/f noise in semiconductors. The changes in the 1/f noise that were observed during the surface cleaning procedure can be correlated with the presence or absence of an inversion layer at the surface.