Distributed charge (sub)micron MOS transistor model

Abstract

A new enhancement MOS transistor model applicable in all operating regimes is presented in the paper. Usually, MOS transistor models are based on a global equivalent circuit. The global capacitor value determination must take into account the charge sharing, and charges must be controlled, i.e. Qs + QD + QB + QG = 0 In this model, the distributed charge model (DCM), charges are distributed along the channel and naturally controlled. The threshold voltage notion disappears, perfecting the continuity between `subthreshold? and strong inversion. The surface potential profile is determined along the channel in the gradual channel conditions using an expression such as ?s = ?s0 + ?V where ? is calculated accurately. The approach used takes into account the 2-dimensional physical behaviour. An analysis of the gate controlled depletion region and the effective channel length determination make possible the use of the model in submicron structures. The new model may have applications in electrical simulation for integrated circuit computer aided design, and in the determination of physical parameters along the MOS transistor channel. No fitting parameter, very often introduced in analytical approaches, is necessary here and the control of charges is obtained.