Quantum confinement effect in short-channel Gate-All-Around MOSFETs and its impact on the sensitivity of threshold voltage to process variations

We have proposed an analytical model for quantum confinement effects in short-channel Gate-All-Around (GAA) MOSFETs. This model accurately predicts the eigen-energy shift and eigen-function modulation caused by the short channel effects in lightly doped GAA devices. It shows that the threshold voltage (V_th) variation due to channel diameter variation is larger than that due to channel length variation because of the significant quantum confinement in ultra-scaled devices. Our model indicates that the channel diameter of GAA MOSFETs can be optimized to reduce the V_th variation.