Comparison of On-The-Fly, DC $I_{d}$–$V_{g}$, and Single-Pulse Methods for Evaluating Threshold Voltage Instability in High-$\kappa$ nMOSFETs

Abstract

Stress-induced degradation of the threshold voltage of high-kappa nMOSFETs measured by on-the-fly and single-pulse methods is investigated. It was found that the relaxation of the stress-induced threshold voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) shift during stress interruption (sensing) time is primarily governed by the fast detrapping of charges trapped through the fast transient charging (FTC) process. Subtraction of the FTC contribution from the total stress time-dependent V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th </sub> shift provides a practical and convenient method for eliminating a major source of V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> relaxation, which results in identical lifetime estimations by the on-the-fly and pulsed methods