An accurate 2-D model for transconductance-to-current ratio and drain conductance of vertical surrounding-gate (VSG) mosfets for microwave circuit applications

An accurate analytical model for the transconductance-to-current ratio (g(m)/I-ds), current-voltage characteristics, and drain conductance is developed for a vertical surrounding-gate (VSG) MOSFET based on the solution of the 2-D Poisson's equation. The dependence of g(m)/I-ds, drain current, and drain conductance on key technological parameters has been analyzed in detail. A design rule to select the device parameters to enhance g(m)/I-ds is proposed. Results show that higher values of g(m)/I-ds can be achieved in VSG MOSFETs as compared to DG MOSFETs. Close agreement with simulated results confirms the validity of the present model. (C) 2001 John Wiley & Sons, Inc.