A New Short-Channel-Effect-Degraded Subthreshold Behavior Model for Double-Fin Multichannel FETs (DFMcFETs)

On the basis of the quasi-three-dimensional scaling equation and minimum bottom-central potential, a new short-channel-effect-degraded subthreshold behavior model for double-Fin multichannel FET (DFMcFET) is presented. It is shown that the deep trench of the DFMcFET is superior to the shallow one in respect of suppressing short-channel effects (SCEs) and reducing the threshold voltage roll-off and subthreshold roll-up. Meanwhile, the wide trench and thin gate oxide are required to resist SCEs and reduce the subthreshold behavior degradation as the channel length is further decreased. In comparison to the counterpart of conventional FinFET, DFMcFET not only provides the more conducting channel, but also enhances the immunity to SCEs due to its shorter scaling length. Besides, both threshold voltage roll-off ΔVTH and subthreshold swing roll-up ΔSS can be well controlled by the scaling theory. The allowable minimum channel length can be uniquely determined according to the criterion of the scaling factor. With its computational efficiency and simple form, the model can be easily used for the circuit application of the DFMcFET.