Silane dissociation mechanisms and thin film formation in a low pressure multipole dc discharge

A silane plasma is generated by a hot cathode dc discharge in a partially confining multipolar magnetic structure yielding hydrogenated amorphous silicon thin films on the walls. The low-pressure range (0.1–5 mTorr) allows the analysis of the elementary processes for SiH4 dissociation. At low silane partial pressure the deposition rate remains in the range of 1–10 Å/sec, but the contribution of ions to deposition can reach up to 80% in contrast with standard glow discharges.