Performance Comparison Between Bulk and SOI Junctionless Transistors

Abstract

The design and characteristics of a junctionless (JL) bulk FinFET were compared with the silicon-on-insulator (SOI) JL nanowire transistor (JNT) using 3-D quantum transport device simulation. The JL bulk FinFET exhibits a favorable ON/OFF current ratio and short-channel characteristics by reducing the effective channel thickness that is caused by the channel/substrate junction. The drain-induced barrier lowering and the subthreshold slope are about 40 mV and 73 mV/dec, respectively, with an ON/OFF current ratio of 10(5) at W = 10 nm. The JL bulk FinFET is less sensitive to the channel thickness than the SOI JNT. Furthermore, the threshold voltage V-th of the JL bulk FinFET can be easily tuned by varying substrate doping concentration N-sub. The modulation range of V-th as N-sub changes from 10(18) to 10(19) cm(-3), which is around 30%.