Physics-based modeling of FinFET RF variability

This paper presents the physics-based variability analysis of multi-fin double-gate (DG) MOSFETs, representing the core structure of FinFETs for RF applications. The variability of the AC parameters as a function of relevant geometrical and physical parameters, such as the fin width, the fin separation, the source (drain)-gate distance and the doping level is investigated. The analysis exploits a numerically efficient Green’s Function technique [1]-[2], extending to the RF case the linearized approach well known from DC variability analysis. The variability of a single fin DG-MOS transistor is compared to a more realistic structure with two fins and raised source/drain contacts, i.e. including both the active part of the FinFET and a significant amount of passive (parasitic) components at the device level. Although presently implemented in a 2D in-house software, the technique can be easily exported to standard 3D TCAD tools, e.g. for tri-gate FinFETs analysis.