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

摘要

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 $L_{rm eff}$) are found to increase the susceptibility to RTN. Our results indicate that under WFV, TFET exhibits weaker correlation between $I_{{rm ON}}$ and $I_{{rm OFF}}$ 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.