Plasma Enhanced Chemical Vapour Deposition of Hydrogenated Amorphous Silicon from Dichlorosilane and Silane Gas Mixtures

Abstract

Hydrogenated amorphous silicon films have been deposited from mixtures of dichlorosilane ( SiH₂Cl₂) and silane by plasma enhanced chemical vapour deposition. The deposition rate is found to increase with the addition of SiH₂Cl₂. At a given rf power, the deposition rate decreases with increasing total flow rate, opposite to that found for deposition with only silane. These results are compared to optical emission data measured under identical deposition conditions, and are discussed in terms of electron attachment to the chlorinated species which modifies the electron energy distribution within the plasma.