Analysis of Single-Trap-Induced Random Telegraph Noise and its Interaction With Work Function Variation for Tunnel FET

Abstract

This paper analyzes the impacts of a single acceptor-type and donor-type interface trap induced random telegraph noise (RTN) on tunnel FET (TFET) devices and its interaction with work function variation (WFV) using atomistic 3-D TCAD simulations. Significant RTN amplitude (Delta I-D/I-D) is observed for a single acceptor trap near the tunneling junction, whereas a donor trap is found to cause more severe impact over a broader region across the channel region. In addition, several device design parameters that can be used to improve TFET subthreshold characteristics (thinner equivalent oxide thickness or longer L-eff) are found to increase the susceptibility to RTN. Our results indicate that under WFV, TFET exhibits weaker correlation between I-ON and I-OFF than that in the conventional MOSFET counterpart. In the presence of WFV, the RTN amplitude can be enhanced or reduced depending on the type of the trap and the composition/orientation of metal-gate grain.