Mobility model based on piezoresistance coefficients for Ge 3D transistor

The conventional first order piezoresistance model has commonly been used to describe carrier mobility enhancement for low levels of process induced stress in Complementary Metal-Oxide-Semiconductor Field Effect Transistor (CMOS) technology. However, many reports show it failing to describe the nonlinear behavior observed at high levels of stress. In this paper, mobility model based on the modified piezoresistance model with nine stress-independent piezoresistance coefficients is proposed such that a mobility model can be applied correctly to calculate the strain-induced carrier mobility changes. Hence, the overall accuracy is improved compared to the conventional piezoresistance (PR) model. Its validation is confirmed with the results from TCAD simulations of carrier mobility for Ge Fin Field Effect Transistors (FinFET) and nanowire transistors.