Design and Analysis of Gate Underlapped/Overlapped Surround Gate Nanowire TFET for Analog Performance

Abstract

In this paper, gate all around (GAA) tunnel field effect transistor (TFET) of the p-type channel is introduced. GAA has better gate control over the channel thereby it provides high ION/IOFF ratio. Since there is horizontal tunneling in conventional GAATFET when we introduce overlapping of the source and drain inside the channel the current abruptly increases and hence ION/IOFF. Sub-threshold slop is below 20 mv/decade in case of drain overlapped GAA. In source overlapped tunneling takes place in two directions while in conventional GAATFET tunneling was at source-channel interface only. Also, we have compared the ON current and OFF current with a variation of the drain current of non-overlapped, source overlapped and Drain overlapped of GAATFET, and we got the better result of drain overlapped GAATFET. In Drain overlapped GAATFET the subthreshold slope is lowest than other two structure so it provides an abrupt increase in ION.