A Novel Effective-Conducting-Path-Induced Scaling Length Model and Its Application for Assessing Short-Channel Performance of Multiple-Gate MOSFETs

Based on the effective-conducting-path conduction mode, a novel scaling length model is successfully developed for the short-channel multiple-gate (MG) MOSFETs. Unlike the conventional central conduction mode (CCM)/surface conduction mode (SCM), where the scaling length only takes geometrical parameters into account, the scaling length accounts for geometrical, material, and electrical parameters that give rise to effective-conducting-path effects (ECPEs) can predict short-channel effects (SCEs) more comprehensively and reasonably than the conventional scaling length. It is revealed that the conventional scaling length stemming from the CCM/SCM will overestimate/underestimate SCEs due to the neglected minimum carrier density distribution in developing the scaling length. Although the decreased/increased device dimension may push the device operation to come near to bulk conduction mode/SCM, the scaling length needs to be adjusted to accommodate the minimum conducting carrier density that primarily dominates the subthreshold behavior. In assessing short-channel performance for the MG devices, the proposed scaling length model that accounts for ECPEs can be used to establish the scaling theory associated with the design space that determines the allowable maximum subthreshold behavior degradation in terms of the criterion of minimum scaling factor.