Plasma-enhanced chemical vapor deposition (PECVD) offers an alternate route to optical thin films, but the relative merits vs conventional methods and between different excitation processes must be evaluated. We investigated the microwave and rf PECVD of SiO_x and SiO_xN_y films using tetraethylorthosilicate (TEOS) mixed with nitrogen, oxygen or nitrous oxide. Plasma emission spectroscopy revealed variations in reactive species' concentrations for different process conditions. Deposition rates were traced for two series of microwave PECVD reactions, and are compared to other processes. For both rf and microwave PECVD processes, film stoichiometry was characterized by IR and Auger spectroscopy. Optical properties were assessed by ellipsometry, IR and visible spectroscopy. Both microwave and rf PECVD process conditions were identified that form SiO_x with less than 2% residual carbon. By varying process conditions, one can span a broad range of SiO_xN_y formulations. Variations in optical properties and film microhardness with changing film stoichiometry are discussed.

Date Published: 7 September 1994
PDF: 10 pages
Proc. SPIE 2262, Optical Thin Films IV: New Developments, (7 September 1994); doi: 10.1117/12.185803

Published in SPIE Proceedings Vol. 2262:
Optical Thin Films IV: New Developments
James D. Rancourt, Editor(s)