Precise Modeling Framework for Short-Channel Double-Gate and Gate-All-Around MOSFETs

A precise modeling framework for short-channel nanoscale double-gate (DG) and gate-all-around (GAA) MOSFETs is presented. For the DG MOSFET, the modeling is based on a conformal mapping analysis of the potential distribution in the device body arising from the interelectrode capacitive coupling, combined with a self-consistent procedure to include the effects of the inversion charge. The DG interelectrode coupling, which dominates the subthreshold behavior of the device, can also be applied with a high degree of precision to the cylindrical GAA MOSFET by performing a simple geometric scaling transformation to account for the difference in gate control in the two devices. Near threshold, self-consistent procedures invoking Poisson's equation in combination with boundary conditions and suitable modeling expressions for the potential are applied to the two devices. In strong inversion, these solutions converge to those of the respective long-channel devices. The drain current is calculated as part of the self-consistent treatment. The results for both the electrostatics and the current are in excellent agreement with numerical simulations.