MOOSE: a physically based compact DC model of SOI LD MOSFETs for analogue circuit simulation

In this paper, we present a compact model for silicon-on-insulator (SOI) laterally double diffused (LD) MOSFETs. The model is complete insofar as it uses no subcircuits, and is intended to predict device operation in all regions of bias. The device current is described by two main equations handling the MOS channel and the drift region, both of which are smooth and continuous in all operating regimes. Attention is also given to the modeling of inversion at the back oxide to ensure correct behavior is predicted for a source follower in power control applications ("high side operation"). A surface-potential-based formulation is used for the inversion/accumulation channel giving smooth transitions between different regions of operation, and care has been taken to ensure all expressions are smooth and infinitely differentiable to achieve the best possible convergence performance. Self (and coupled) heating effects exert a major influence over the behavior of power SOI devices, and these issues are incorporated in the model core in a consistent fashion. The model has been installed in a commercial SPICE-type circuit simulator and evaluated against individual devices and complete circuits fabricated in an industrial smart power SOI process. Accuracy is significantly improved with respect to the existing LDMOS models, and convergence behavior in switching and linear circuit simulations is comparable with industry standard models of this complexity.