An AES study of the influence of carbon on the chemical structure of some oxide films deposited by PECVD of organosilicon precursors

Abstract

AES is used to analyze carbon-containing Si oxide films produced by PECVD of a silicon-source gas, like tetraethoxysilane or hexamethyldisiloxane, diluted with oxygen. Auger Si LVV spectra reveal a large contribution typical of SiO x species with Si atoms surrounded by less than four O atoms. Besides, the signature of Si–C bonds is detected. It is suggested that Si atoms bond simultaneously to O and C atoms, so that, the higher the carbon content is, the larger is the deviation from the dioxide stoichiometry. The dominant Si species are somewhat dependent on the chemical structure of the precursor molecule. Auger C KVV spectra indicate that C atoms enter C–Si and C–H bonds with no particular evidence of C–C bonds.