Possibility of SOI based super steep subthreshold slope MOSFET for ultra low voltage application

Abstract

Ultra Low Power (ULP) LSI's require the steep subthreshold slope (SS) MOSFET. However, the theoretical SS limit of the conventional MOSFET is 60mV/dec at the room temperature. Recently, devices which have the less than 60mV/dec SS, such as the Tunnel FET (TFET) and the Impact Ionization MOS (I-MOS), have been studied. In addition to those, the steep SS MOSFET's using the Floating-Body (FB) SOI have been proposed. In this work, we report our finding of the FB and the Body-Tied (BT) SOI MOSFET with the super steep SS (<; 1mV/Dec) characteristics with the 0.15um SOI. We also discuss the possibility of it as a switching device for the ultra low voltage application, where we consider that the three points are the issues to improve; reducing the operation voltage, increasing Ion/Ioff ratios which also pay attention keeping the low Ioff, controlling hysteresis characteristics.