Current-voltage characteristics of semiconductor power devices operating at high current densities

The forward current voltage characteristics of semiconductor power devices was analyzed, taking into account consequences of high current density at which modern devices operate. The analysis was based on the equation of diffusion for the phenomenological model, with the recombination rate depending on the Auger constants and on the Schottky-Reed lifetime statistics. It is solved here for diodes with p(+)nn(+) structure. Calculations reveal that the voltage drop across the base layer depends largely on the ratio of lifetimes of injected charge carriers in the base and in the emitter. The results indicate that at high current densities it is Auger recombination rather than electron hole scattering which determines how linear the forward current voltage characteristic of devices with wide base structure will be.