Modeling of Nanoscale 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. In the subthreshold regime, the modeling of the electrostatics of the DG MOSFET is based on a conformal mapping analysis. This analytical 2D solution of Laplace's equation gives the inter-electrode capacitive coupling. The GAA MOSFET is a 3D structure to which the 2D conformal mapping technique is not directly applicable. However, due to the structural similarities, the DG calculations can also be applied with a high degree of precision to the cylindrical GAA MOSFET by performing a simple geometric scaling transformation. Near and above threshold, self-consistent procedures invoking the the 2D/3D Poisson's equation in combination with boundary conditions and suitable modeling expressions are used to model the electrostatics of the two devices. The drain current is calculated as part of the self-consistent treatment, and based on the precise modeling of the 2D/3D electrostatics the intrinsic capacitances can also be extracted.

Auteur

Håkon Børli received the Sivilingeniør (Master) and the Ph.D. degrees from the Norwegian University of Science and Technology, Trondheim, in 2000 and 2008 respectively. He is currently senior design engineer in Silicon Labs.