Calculation of Bipolar Transistor Base Resistance Using Finite Element Method

To model NPN-transistor behaviour at high currents or high frequencies, an exact description of base resistance is needed. In this paper a new method for base resistance calculation is presented, that takes into account three-dimensional physical effects at high currents. A distributed equivalent circuit is generated for each NPN-transistor layout using the finite element method. Calculating the power dissipation in the base region, the corresponding base resistance is obtained from equivalent power consumption.