Compact Analytical Threshold-Voltage Model of Nanoscale Fully Depleted Strained-Si on Silicon Germanium-on-Insu lator (SGOI) MOSFETs

In this paper, a physically based analytical threshold-voltage model is developed for nanoscale strained-Si on silicon-germanium-on-insulator MOSFETs for the first time, taking into account short-channel effects. The model is derived by solving the 2-D Poisson equation in strained-Si and SiGe layers. The effects of various important device parameters like strain (Ge mole fraction in the SiGe layer), body doping, gate workfunction, strained-Si thin film and SiGe layer thickness, etc., has been considered. We have demonstrated that increasing strain in order to enhance device performance can lead to undesirable threshold-voltage rolloff. The model is found to agree well with the 2-D simulation results