A new approach for physical-based modelling of bipolar power semiconductor devices

Abstract

This paper presents a hybrid approach for accurate modelling and simulation of power bipolar semiconductor devices. Model's core is a numerical module that solves ambipolar diffusion equation (ADE) trough a variational formulation followed by an approximate solution with a finite element approach. The approach enables easy implementation of physics-based power semiconductor models into standard SPICE circuit simulators. Implementation is done trough a set of current controlled RC nets describing charge carrier distribution in low-doped zone. Other zones of devices are modelled with classical methods in an analytical module. With this hybrid approach it is possible to describe dynamic and static device behaviour with good accuracy while maintaining low execution times. The methodology is presented and applied for power p-i-n diodes, power bipolar junction transistors and insulated gate bipolar transistors. Models are validated comparing experimental and simulated results.