Compact modeling of short-channel effects in symmetric and asymmetric 3-T/4-T double gate MOSFETs

In this paper, a two dimensional compact model for the potential distribution of double gate MOSFETs is presented. The approach uses the evanescent method along with the assumption of a parabolic potential distribution in the direction transverse to the channel in the subthreshold region and at the threshold condition. The model introduces a characteristic length which is obtained using an explicit expression. The model may be applied to all double gate structures including both symmetric and asymmetric, 3-terminal (3-T) and 4-terminal (4-T) devices. Based on this potential distribution model, the main short-channel effects including subthreshold swing, drain induced barrier lowering, and the threshold voltage are investigated. The model shows an excellent fit to data obtained from a numerical simulator in predicting the characteristics of an arbitrary DGMOSFET.