Gas Phase Diagnosis of Disilane/Hydrogen RF Glow Discharge Plasma and Its Application to High Rate Growth of High Quality Amorphous Silicon

Abstract

Gas phase diagnosis of disilane/hydrogen plasma was carried out using mass spectrometry. At high growth rate (20 Å/s) conditions using pure disilane as a source gas, the partial pressure of disilane molecules measured by mass spectrometry was more than one order of magnitude higher than in the case when mono-silane was used as a source gas. The stability of amorphous silicon films prepared from disilane was improved by the hydrogen dilution technique, although the disilane partial pressure in this condition was much higher than in the case when mono-silane was used as a source gas for device quality films. The relation between the gas phase species and the stability of the resulting films is studied. It was found that increase in disilane related signal intensity do not decrease film stability directly.