Effect of Power on the Properties of SiO2 Films Produced by Plasma-Enhanced Chemical Vapour Deposition

Abstract

ABSTRACTThe effect of power on the properties of SiO2 films produced by direct plasma-enhanced chemical vapor deposition using nitrous oxide and silane with high helium dilution has been investigated. As the power increases the p-etch rate decreases while the frequency of the Si-O-Si stretching vibration measured by Fourier transform infra-red spectroscopy increases. However the refractive index of the films measured by ellipsometry is almost constant as is the electron density measured by low-angle x-ray reflection, indicating that the structural changes of the film with power do not relate to bulk density changes. The x-ray and ellipsometry measurements indicate the existence of a transitional layer with monolayer dimensions at the Si/SiO2 interface.