Novel attributes of a dual pocket tunnel field-effect transistor

Abstract

In this paper, we propose the application of a dual pocket adjacent to the source in a tunnel field effect transistor (TFET) to improve its electrical characteristics. Using two-dimensional device simulations, we demonstrate that if appropriate doping concentration and length are chosen for the dual pocket, then a sharp curvature is obtained in the energy bands at the onset of tunneling. Consequently, a smaller tunneling width and higher band-to-band tunneling are obtained in a dual pocket TFET (DP-TFET). We demonstrate that the proposed DP-TFET exhibits a 64% smaller average subthreshold swing (SS) compared to a conventional TFET and a 39% smaller average SS compared to a TFET in which a single fully depleted counter-doped pocket adjacent to the source is added. Moreover, the proposed technique of inserting a dual pocket is effective at lower supply voltage (V DD = 0.5 V). Therefore, we can obtain a high ON-current to OFF-current ratio at lower supply voltages and the proposed technique can be employed in future TFETs for low power applications.