Methyl- and dimethyl-associated paramagnetic centers in SiO₂ thin films

Abstract

SiO2 thin films, deposited by the plasma-enhanced chemical vapor deposition technique using tetraethylorthosilicate (TEOS) and O2 as precursors, exhibit electron-paramagnetic-resonance signals that are interpreted in terms of methyl- and dimethyl-associated centers. The former are observed in as-deposited films and in films thermally treated below 500 °C while the latter are observed in films that have been thermally treated between 700 and 950 °C. These hydrocarbon-containing paramagnetic centers originate from TEOS's ethyl constituents that are incorporated in the SiO2 film during growth.