Hole scattering mechanism of strained Si/(111)Si1−x Ge x

Abstract

Based on Fermi’s golden rule and the theory of Boltzmann collision term approximation, the hole scattering mechanism of strained Si/(111)Si1−xGex was established, including ionized impurity, acoustic phonon, non-polar optical phonon and total scattering rate models. It was found that the total scattering rate of the hole in strained Si/(111)Si1−xGex decreased obviously with the increasing stress when energy was 0.04 eV. In comparison with one of the unstrained Si, the total hole scattering rate of strained Si/(111)Si1−xGex decreased about 38% at most. The decreasing hole scattering rate enhanced the hole mobility in strained Si materials. The result could provide valuable references to the research on hole mobility of strained Si materials and the design of PMOS devices.