Chemical etching of thin SiO C H films by post-deposition x y z exposure to oxygen plasma

SiO C H films deposited in a O rTEOS plasma are post-exposed to an oxygen plasma. Real-time ellipsometric x y z 2 measurements combined with optical emission spectroscopy show a strong etching of the film in the first minutes. Spectroscopic ellipsometry, transmission electron microscopy TEM.and Auger spectroscopy evidence structural modifications over several 10 nanometers. It is also shown that chemical reactions with O atoms are responsible for most of this effect and that during a deposition process there is really competition between deposition and etching by O atoms. q1999 Elsevier Science B.V. All rights reserved.