Cause analysis of width-dependence of on-current variability in thin gate-all-around silicon nanowire MOSFET

Abstract

In this study, the width dependence of on-current variability in extremely narrow gate-all-around (GAA) silicon nanowire MOSFET down to 2nm width is analyzed by variability decomposition into components as well as analyzing the Pelgrom plot. It is found that the current variability rapidly increases below 4nm mainly due to quantum-effect-induced threshold voltage variability and silicon-thickness-fluctuation-induced mobility fluctuation (μfluctuation). The current variability becomes even worse in 2nm, which is fundamentally caused by line width roughness.