Charged carrier transport in Si1−<i>x</i>Ge<i>x</i> pseudomorphic alloys matched to Si—strain-related transport improvements

Abstract

Charge carrier transport studies are reported for Si1−xGex pseudomorphic alloy layers matched to the (001) Si substrate lattice constant. The effect of biaxial compressive strain on transport is studied by first examining the band structure changes via deformation potential theory and then studying the transport via a generalized Monte Carlo approach. Marked improvements in in-plane hole transport are obtained while significant improvements also occur in the out-of-plane electron transport. These changes are ideally suited for use in n(Si)-p(Si1−xGex)-n(Si) heterojunction bipolar transistors.