Photoinduced effects in RF and VHF a-Si : H films deposited with differention bombardment

Hydrogenated amorphous silicon (a-Si:H) films were deposited in a diode-typ e reactor in RF and VHF discharge under controlled ion bombardment. Defect concentration in the films was studied as a function of the energy of ions impinging on the growing film in as-grown (A), light-soaked (B), and anneal ed states (C). Significant changes in defect concentration, and Fermi-level position with ion energy were observed in the samples in A-and C-states, w hile ion bombardment caused less changes in the properties in the B-state. The data obtained are discussed in terms of the generation of D-0 and D_ de fect states, which are controlled by ion bombardment of the films during gr owth. (C) 2001 Published by Elsevier Science B.V. All rights reserved.