Collector recombination lifetime from the quasi-saturation analysis of high-voltage bipolar transistors

A novel method of measuring the collector recombination lifetime, which is independent of emitter effects, is presented by extending the quasi-saturation analysis of high-voltage bipolar transistors to the high-current-density regime. The technique is supported by theory, and experimental results are presented on transistors fabricated with different emitter properties. This is a nondestructive method and gives the lifetime values at the current densities normally encountered when the transistor is in actual operation. The values for the collector recombination lifetime obtained by the present method are independent of the properties of the emitter region