Novel extraction of emitter resistance of SiGe HBTs from forward-Gummel measurements

A simple dc method for determining the emitter series resistances of bipolar transistors from the measured forward-Gummel characteristics is proposed. The method is successfully applied to a set of SiGe HBTs with different sizes, which have been fabricated and measured over a large temperature range. As a result, the temperature scaling and geometric scaling characteristics of the extracted emitter series resistances are analyzed and discussed.