Numerical analysis and analytical modeling of RDF in DG Tunnel-FETs

The ongoing scaling of semiconductor devices is leading to a growing influence of discrete dopants on the device electrostatics. This discretization is accompanied by an increasing dependency of the resulting device currents on the dopant distribution. Hence, the need to consider random dopant fluctuations (RDF) in compact models is a necessity to predict and understand present device current variances. In this paper a first approach is presented to predict device geometry based RDF. The model is compared to different TCAD simulation methods for RDF in DG-Tunnel-FETs. Thereby, an untypical behavior special to Tunnel-FETs is discovered, where decreasing doping levels result in higher gate voltage variances. Furthermore, a negative effect of discrete dopants on the steepness of the subthreshold slope is discussed.