An insulated-gate bipolar transistor model based on the finite-volume charge method

Abstract

A finite-volume charge method has been proposed to simulate PIN diodes and insulated-gate bipolar transistor (IGBT) devices using SPICE simulators by extending the lumped-charge method. The new method assumes local quasi-neutrality in the undepleted N− base region and uses the total collector current, the nodal hole density and voltage as the basic quantities. In SPICE implementation, it makes clear and accurate definitions of three kinds of nodes — the carrier density nodes, the voltage nodes and the current generator nodes — in the undepleted N− base region. It uses central finite difference to approximate electron and hole current generators and sets up the current continuity equation in a control volume for every carrier density node in the undepleted N− base region. It is easy to increase the number of nodes to describe the fast spatially varying carrier density in transient processes. We use this method to simulate IGBT devices in SPICE simulators and get a good agreement with technology computer-aided design simulations.