Growth-induced surface state in hydrogenated and fluorinated amorphous silicon

Abstract

The steady-state density of surface states during the deposition of hydrogenated and fluorinated amorphous silicon (a-Si:H,F) can be adjusted via the deposition parameters, particularly the growth pressure. The density of surface states can be frozen in if the sample is cooled immediately after the termination of growth. We have measured frozen in densities of surface states between 1.5×1012 cm−2 and 4×1014 cm−2. a-Si:H,F grown at high density of surface states exhibits a small Urbach energy and a low bulk defect density.