A model of the chemical vapor deposition of Si1-x-yGexCy films from silane, germane and methyl silane
M. W. Stoker
, 
, a, T. Merchanta, A. Mortonb and J. Hildrethb
a Semiconductor Products Sector, Motorola Inc., 2100 E. Elliot Rd, Tempe, AZ 85284, USA
b Semiconductor Products Sector, Motorola Inc., 1300 N. Alma School Rd, Chandler, AZ 85224, USA
Available online 14 June 2003.
A model has been developed for the chemical vapor deposition of epitaxial Si1-x-yGexCy films from SiH4, GeH4 and SiH3CH3. The model is based on a simplified chemical mechanism including adsorption and decomposition of SiH4, GeH4 and H2 on vacant Si or Ge sites and subsequent H2 desorption. The model focuses on effects at relatively high pressures (i.e., 1–200 Torr) where suppression of deposition by adsorbed hydrogen becomes important, resulting in an inverse dependence of the deposition rate on pressure and giving rise to a strong dependence of Ge concentration on the deposition temperature. The model assumes that this temperature dependence is due to the influence of adsorbed hydrogen on segregation of Ge to the surface and the relative concentration of vacant Si and Ge sites. The model also includes a simple treatment of carbon incorporation from SiH3CH3. The model predictions of deposition rate, Ge content and both total and substitutional carbon content compare favorably with experimental data over a wide range of conditions.
Author Keywords: Silicon germanium; Substitutional carbon; Kinetic mechanism
