Electron exo-emission study of PECVD and thermal CVD silicon rich silicon oxide

Silicon oxide films have been deposited by the PECVD and Thermal CVD methods under different deposition conditions and using different source gases. The FTIR spectra of these films reveal varying microstructure in terms of the Si-O stoichiometry for films prepared under different sets of process conditions. The room temperature photoluminescence spectra of the as deposited films show a luminescence band around 400 nm. The 400 nm band remains as it is, while the 580 nm band arises after high temperature rapid thermal anneal. These bands have been detected even earlier and are attributed to defects in the Si-O network and from silicon nano-crystals present in the SiO2 host matrix, respectively. We studied the exo-emission of electrons as a function of temperature of the as deposited and the annealed films. The exo-emission data reveal four narrow bands at different temperatures. We try to explain these on the basis of tunneling of electrons with different energies across the potential barriers present at the silicon nanoparticle-SiO2 matrix interface. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.