Model for the potential drop in the silicon substrate for thin-film SOI MOSFETs

Abstract

An analytical model is proposed for calculating the potential drop in the silicon substrate for thin-film SOI MOSFETs. The model is verified by numerical simulation, and indicates that the substrate potential causes a nonlinear shift of the threshold voltage for varying back gate voltages. Although this shift is shown to be rather limited for today's SOI fabrication parameters, it will increase if thinner buried oxides are used in the future.