A Second-Order Surface Potential Core Model for Submicron MOSFETs

With the maturity of CMOS technologies and their use in low-voltage analog applications, the accuracy of SPICE models is very important. Here, an extremely accurate yet simple form of the charge-sheet model is developed using a symmetric polynomial interpolation of the charge in the channel. This formulation of the drain current retains the same simplicity of the industry-standard surface potential MOSFET models based on the symmetric linearization method (SLM). But, unlike the SLM, it is developed without requiring the linearization of the charge in the channel, hence, the asymmetries and the nonlinearity are accurately accounted for. The model, although more accurate, has the same computational efficiency and easy implementation of the SLM. Finally, the equations of the currents and terminal charges can be worked out to have the same mathematical form as the SLM.