Chemical etching of thin SiOxCyHz films by post-deposition exposure to oxygen plasma

SiOxCyHz films deposited in a O-2/TEOS plasma are post-exposed to an oxygen plasma. Real-time ellipsometric measurements combined with optical emissio n spectroscopy show a strong etching of the film in the first minutes. Spec troscopic ellipsometry, transmission electron microscopy (TEM) and Anger sp ectroscopy evidence structural modifications over several 10 nanometers. It is also shown that chemical reactions with O atoms are responsible for mos t of this effect and that during a deposition process there is really compe tition between deposition and etching by O atoms. (C) 1999 Elsevier Science B.V. All rights reserved.