An Improved Surface-Potential-Based Model for MOSFETs Considering the Carrier Gaussian Distribution

In this article, an improved surface-potential-based current model for MOSFETs is proposed to characterize the Gaussian distribution phenomenon of carrier concentration. First, the lumped parameter equivalent circuit model is established. Then, in order to improve the current model accuracy for the large width–length ratio (WLR) transistors, the channel carrier distribution is studied. Based on this, the conventional drain–source current model is modified. Besides, the parameters related to the carrier distribution along the channel are extracted. In order to validate the improved model, different WLR transistors were fabricated and measured. Furthermore, the model calculation results are compared with the measurement data. The root-mean-square error (RMSE) of drain–source current is reduced from 3.537 to $0.354~\mu \text{A}$ in the subthreshold region and decreased by 76% in the linear region. As a result, the proposed model is reliable and predictable, which is helpful for the RF circuits design.