Longitudinal, transverse, density-of-states, and conductivity masses of electrons in (001), (101) and (111) biaxially-strained-Si and strained-Si1−x Ge x

Abstract

In this study, the electron effective masses, including longitudinal, transverse, density-of-states and conductivity effective masses, have been systematically investigated in (001), (101) and (111) biaxially strained Si and Si1−xGex. It is found that the effect of strain on the longitudinal and transverse masses can be neglected, that the density-of-states masses in (001) and (110) biaxially strained Si and Si1−xGex materials decrease significantly with increasing Ge fraction (x), and that the conductivity masses along typical orientations in (001) and (110) strained Si and Si1−xGex.are obviously different from those in relaxed Si. The quantitative results obtained from this work may provide valuable theoretical references to understanding strained materials physics and studying conduction channel design related to stress and orientations in the strained devices.