A comprehensive model to predict dopant diffusion (Sb, As, B and P) in epitaxially strained SiGe CMOS transistors was presented. The effect of Ge was primarily comprehended as a change in point defect populations (self-interstitials and vacancies). The analysis validates this approximation for most dopants (Sb, As, Ge, and P). With Ge concentration, the vacancy population increases much more than the interstitial concentration. Consequently, the fractional interstitial mediated diffusion decreases with increasing germanium. For B an additional change in pair formation/migration energy was required to explain the observed experimental data. The model was used to explore heteroepitaxially grown SiGe/Si device design options.

Dopant Diffusion Modeling for Heteroepitaxial SiGe/Si Devices. S.Chakravarthi, P.R.Chidambaram, C.F.Machala, M.Mansoori: Journal of Vacuum Science & Technology B, 2006, 24[2], 608-12