Dislocation scatterings in p-type Si1-xGex under weak electric field

Abstract

We present a theoretical model which describes hole mobility degradation by charged dislocations in p-type Si1-xGex. The complete analytical expression of the dislocation mobility is calculated from the momentum relaxation time of hole carriers under weak electric field. The obtained dislocation mobility shows a T-3/2/lambda relation and is proportional to the germanium density x. We also suggest a criterion for negating scatterings by dislocations in terms of the controllable parameters such as acceptor dopant density, dislocation density, temperature, and Ge density x, etc.