Mobility Model Parameters of Strained Si by Using a Quantum Drift Diffusion Model

Abstract

In this study, we have investigated model parameters of a low-field mobility model in the quantum drift diffusion (QDD) model for strained Si channel MOSFETs. Doping dependence of electron mobility in strained Si for different Ge contents in SiGe has been analyzed. The analysis has been performed by changing the Ge contents x from 0 to 0.4 in Si_1-xGe_x. The model parameters of the mobility model are evaluated by comparing with the data calculated by using Monte Carlo method which replicates the experimental data with high accuracy. The effects on the current voltage characteristics for MOSFETs have been simulated by using the QDD model. It is found that the drain current increases as the strain increases and the rate of the increase saturates. The increase ratio of the drain current (at gate voltage is 0.7 V) is 31.0% in the range from x =0 to 0.2 and is only 4.27% in the range from x =0.2 to 0.55.