Unified Compact Modeling of Emerging Multiple-Gate MOSFETs

A generic double-gate (DG) MOSFET follows a generalized voltage equation from the first integral of Poisson equation and Gauss´ law applied at the two gates, which is implicit and, in general, non-integrable when the silicon film is doped. Only DG with undoped body can be solved with implicit surface-potential solutions, or approximate surface-potential solutions for doped symmetric-DG (s-DG) structures. The most challenging task in DG compact modeling is the surface-potential solutions for the generic asymmetric-DG (a-DG) doped-body device: scalable over oxide thickness (from DG to SOI), body thickness and doping (from ultra-thin-body/fully-depleted to bulk-like/partially-depleted), and gate bias (from s-DG and common-gate a-DG to independent-gate a-DG). Once it is conquered, the model will be able to cover different structures and operations with seamless transitions. Another challenge is extension of a DG model to multiple-gate (MG) such as tri-gate (TG) and silicon nanowire (SiNW) devices, or a unified model that encompasses all different configurations. In this paper, we present solution methods towards such a unified MOS compact model based on the unified regional modeling (URM) approach.