Study of the electrical parameters of a dual-material double-gate TFET using a strained type II staggered Ge 1− x − y Si x Sn y /Ge 1− a − b Si a Sn b heterojunction

A strained Ge 1− x − y Si x Sn y /Ge 1− a − b Si a Sn b direct type II staggered heterojunction n -channel tunneling field-effect transistor (FET) with a dual-material double gate is proposed herein. A high- K gate dielectric is used to improve the overall device performance. The energy bandgap for strained Ge 1− x − y Si x Sn y grown on a relaxed Ge 1− a − b Si a Sn b layer is determined using the generalized approach of Menendez and Kouvetakis (MK). Poisson’s equation is solved by using a parabolic approximation to determine the surface potential and electric field. The drain current is calculated using the tunneling generation rate obtained from Kane’s model. A significant improvement of the drain current is observed as compared with that of previously reported Si-based TFETs.