Comparative Study of Single and Double Gate All Around Cylindrical FET Structures for High-K Dielectric Materials

Abstract

The performance of conventional MOSFET deteriorates because of the short channel effects that appears when it is scaled into nm regime. The existing techniques like channel scaling, variations in the work function implemented on a MOSFET could no longer confront these limitations which demand for the necessity of some upgraded devices and materials that would overcome these shortcomings and offer ameliorate performance. Two experimentally based devices gate all around (GAA) FET and double gate all around (DGAA) FET are modeled and compared at 10 nm and 20 nm respectively In this paper, the effect of scaling the gate length, oxide thickness and variations in the drain to source voltage utilizing two different gate dielectrics for a single and double GAA cylindrical FET on their respective device performance in terms of drive current (ION), leakage current (IOFF), switching speed (ION/IOFF) and subthreshold swing. The study reveals that with a thinner gate oxide, less gate length, less drain to source voltage and with an additional core gate utilizing high-k dielectric materials, the device achieves a better subthreshold slope, higher value of ON-state current, larger ON/OFF current ratio, lesser OFF-state current and lesser power consumption.