In this paper, we describe a complete MOSFET model developed for circuit simulation based on fully consistent physical concept. The model describes all transistor characteristics as a function of surface potentials, which are calculated iteratively at each applied voltage under the charge-sheet approximation. The key idea of this development is to put as much physics as possible into the equations describing the surface potentials. Since the model includes both the drift and the diffusion contributions, a single equation is valid from the subthreshold to the saturation regions. Contrary to the expectation, the results show that our semi-implicit model including the iteration procedures can even reduce the CPU time significantly in comparison with a conventional model similar to BSIM2 including short-channel effects. This is due to the consistent description of the model equations for all transistor characteristics, which results in more straightforward device equations, once the surface potentials have been computed.

The reliability of CAD is dependent on the accuracy of models implemented into circuit simulators. However, precise models such as based on 2D numerical modeling are time consuming. Therefore, simplified analytical models have been developed and widely used. A problem is that such existing models are not valid for advanced MOSFETs with sub-micron channel length due to applied simplifications. By introducing fitting parameters to describe each additional short-channel phenomenon, the consistency of the models is violated. As a result the calculation time for circuit simulation increases considerably. In this paper the authors present a newly developed MOSFET model which describes the transistor characteristics consistently without any nonphysical fitting parameters. Using this model the calculation time is reduced in comparison with the conventional model due to the consistent inclusion of short-channel effects and the diffusion contribution to the carrier transport.>