A closed-form charge-based expression for drain current in symmetric and asymmetric double gate MOSFET

Abstract

Although both exact [Taur Y, Liang X, Wang W, Lu H. A continuous, analytic drain-current model for DG MOSFETs. IEEE Electron Dev Lett 2004;25(2):399–401] and design oriented approximate [Sallese JM, Krummenacher F, Prgaldiny F, Lallement C, Roy A, Enz C. A design oriented charge-based current model for symmetric DG MOSFET and its correlation with the EKV formalism. Solid-State Electron 2005;49(3):485–9] closed-form analytical solution of the drain current for the symmetric double gate (DG) MOST exist, a closed-form expression for asymmetric DG MOST is still lacking. In this context, this work presents a semi-empirical analytic closed-form charge-based expression for the drain current of asymmetric DG MOST that is valid from weak to strong inversion and retains the asymptotic behavior. In addition, important small-signal quantities such as the transconductance-to-current ratio are readily obtained and reveal that these are nearly insensitive to the degree of asymmetry.