A new approach for extracting base width modulation parameters in bipolar transistors

A new dc measurement technique that allows a direct observation of the Early effects and the base push-out effect in vertical bipolar transistors is described. The technique uses a special test structure and may be used to accurately determine the forward and reverse Early voltages used in the Gummel Poon model. The improvements provided by this method over conventionally used parameter extraction techniques are demonstrated through measurements on silicon and through two-dimensional device simulations.