Influence of corner effect on performance of three-dimensional tunnel field-effect transistor

Abstract

The electrical performance of the three-dimensional (3D) tunnel field-effect transistor (TFET) was investigated via 3D numerical simulation. It was shown that the rectangular tri-gate (ReTG) TFET has a higher on-state current (Ion) and smaller subthreshold swing (SS) than those of the planar single-gate (SG) TFET owing to the gate control enhancement in the corners of the channel. On the basis of this observation, a trapezoidal tri-gate (TpTG) TFET was proposed, and its electrical properties were optimized. It was demonstrated that Ion increased and SS decreased as the corners become sharper. When the trapezoidal channel become triangular, Ion was approximately enhanced by over 500% and SS was reduced by 33% with respect to the planar SG TFET. In addition, as the channel length shrinks, both the ReTG TFET and triangular tri-gate TFET can efficiently suppress the off-state current.