Charge Collection in Bipolar Transistors

Charge collection measurements on bipolar test structures have shown the presence of a charge transfer process, that has been referred to as the ion shunt effect. This process had been previously seen in CMOS test structures. The transfer of charge from the emitter to the collector has been demonstrated to be a localized effect requiring that the ion track pass through both the emitter and collector. Measurements performed on transistors with and without a buried oxide layer showed large differences in charge collection.