Preparation and Some Properties of Chemically Vapor-Deposited Si-Rich SiO and Si3N4 Films

Abstract

Films of SiO2 and Si3N4 containing excess Si were prepared by chemical vapor deposition at 700 °C by the reaction of gaseous SiH4 and N2O for the Si-rich SiO2 and NH3 for the Si-rich Si3N4. By adjusting the gas-phase ratio of the reactants it was possible to vary the amount of Si in the films. Transmission electron microscopy studies revealed that the films contain two amorphous phases. One phase is amorphous Si while the other is SiO2 or Si3N4. The Si content of the films was measured by electron microprobe analysis. Ellip-sometry measurements on the films were made at several angles of incidence in order to measure the film absorption coefficients which were found to increase with increasing Si content. The d-c conduction characteristic for the Si-rich films was found to be nonohmic. The resistivity at any given field was found to decrease with an increase of the Si content. © 1978, The Electrochemical Society, Inc. All rights reserved.