Dependence of Threshold Voltage Shift on Material Composition for Si-Sir-Ge» Heterostructure p-MOSFET

Abstract

Shift of threshold voltage for Si-Si1-xGex heterostructure p-MOSFET is analytically evaluated for different substrate material composition. Poisson's equation is analytically solved subjected to practical range of tuning parameters and threshold is computed as a function of gate length in presence of body effect. Effect of High-K dielectric is calculated, and compared with that obtained for conventional SiO2 material. Result shows significant change of threshold in sub-micron gate length for different substrate compositions, as well as for high-K dielectrics, which can be effectively utilized for computing subthreshold current in presence of tunneling.