The effect of oxygen on film deposition of a-Si:H by tetrode RF sputtering

Abstract Hydrogenated amorphous silicon (a-Si:H) films were deposited using the tetrode RF sputtering method by changing the hydrogen-to-argon pressure ratio, ξ, under the following conditions: (1) the oxygen contamination condition and (2) the condition which prevents oxygen contamination. The effect of oxygen incorporated into the films on the optical and electrical properties of the films was studied, comparing the properties of films deposited under both conditions. The average values of μτ (μ and τ are the mobility and lifetime of photo-generated carriers, respectively) were calculated using the measurement results of the photoconductivity and complex refractive indices of the films deposited under both conditions. The current-voltage characteristics of Au/a-Si:H Schottky junctions which are composed of a-Si:H films deposited under both conditions were measured. The results suggest that oxygen incorporated into the films acts as recombination centers for photo-generated carriers in the films deposited in the range ξ>10%.