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 (ΔI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</sub> /I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</sub> ) 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 <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">eff</sub> ) are found to increase the susceptibility to RTN. Our results indicate that under WFV, TFET exhibits weaker correlation between <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OFF</sub> 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.