Impact of interface traps on the BTBT-current in tunnel field effect transistors

Abstract

In this paper, we analyze the susceptibility of the Band-to-Band tunneling (BTBT) current subjected to the interface traps in silicon tunnel field effect transistors (TFET). The study quantifies the BTBT current against the types of interface traps (donor or acceptor), its density (NtD or NtA), and the corresponding trap energy level (Etrap) within the forbidden gap. It is observed that the acceptor-type traps deteriorate the BTBT mechanism in an n-TFET while it improves the same in a p-TFET. A similar, however, opposite observation is obtained for the donor-type traps. Further, it is observed that a small trap density (1×10¹¹ cm⁻³) has little impact on the BTBT (due to large band-gap in silicon) while a larger value (5×10¹² cm⁻³) changes the BTBT substantially. Moreover, it is shown that the trap energy location (Etrap =3D 1.0 eV) increases BTBT when closer to the conduction band for n-TFET while for p- TFET, a similar observation is made when Etrap is located closer to the valence band.