Transient effects in floating body SOI NMOSFET's

Abstract

SOI technology is promising to extend bulk CMOS for digital applications. For that purpose, the packing density is key point, such that adding body ties is not considered for most of the SOI devices of digital circuits. The consequence of floating body operation is the existence of several phenomena, like the kink effect and supra ideal subthreshold slope. This paper reports the associated transient effects observed for fast gate pulses by high speed measurement and 2-D numerical simulations. It is indicated that, due to floating body operation, the drain current of SOI devices during fast switching is very different from the DC value. This must be taken into account for accurate simulation of circuits.