A Unified Quasi-3D Subthreshold Behavior Model for Multiple-Gate MOSFETs

Based on the quasi-3D potential approach, a unified subthreshold-potential, threshold-voltage, and subthreshold-current model is developed for multiple-gate mosfet s including a quadruple-gate, triple-gate, and omega-gate mosfet . This work indicates that the scaling-length-oriented subthreshold current roll-up Δ I _sub and threshold voltage roll-off Δ V _th provide the physical insight into well-controlled short-channel effects (SCEs) in terms of effective scaling length λ _eff according to the scaling factor. Besides the decreased minimum conducting channel potential Φ _{C ,min} , the smaller scaling-length-induced effective channel width/height ( W _eff / H _eff ) reflects the smaller effective conducting cross-sectional area, which reduces the subthreshold current degradation due to the increased subthreshold resistance R _sub . By accounting for the coupling factor in the quasi-3D potential approach, W _eff , H _eff , and Φ _{C ,min} will be increased to some extent to decrease R _sub , which, hence, degrades the subthreshold behavior more extensively in response to SCEs.