Hot carrier degradations of dynamic threshold silicon on insulator p-type metal-oxide-semiconductor field effect transistors

Abstract

In this study, we compared the hot carrier effects of T-gate and H-gate Silicon on Insulator p-Type Metal-Oxide-Semiconductor Field Effect Transistors (SOI pMOSFETs) operating under dynamic threshold mode (DT-mode) and normal mode at various temperatures. By operating under DT-mode, the threshold voltage shift is reduced. However, enhanced degradations in maximum transconductance and drive current are observed when operating under DT-mode at room temperature, especially for the T-gate structure. The transconductance enlargement effect for devices operating under DT-mode, together with the non-uniform potential distribution in T-gate structure, are believed to be responsible for the observed enhanced degradations. At elevated temperatures, the hot-carrier-induced degradations are alleviated for devices operating under DT-mode, to levels close to those of the normal mode, due to reduced impact ionization at higher temperature.