In this paper we present a summary of the most important critical issues in
Si/Si1-xGex p-type and n-type heterostructure field-effect transistors. Th
e controversial issue of alloy scattering and the phenomenon of velocity ov
ershoot are reviewed and discussed. Achievements and problems associated wi
th channel engineering and the use of alternative gate electrodes and high-
kappa dielectric materials are also addressed. (C) 2001 Elsevier Science Lt
d. All rights reserved.