The shorted-anode or hybrid insulated-gate bipolar transistor (HIGBT) is examined theoretically (using a first-order analysis) and experimentally (using specially designed test structures) to give physical insight regarding the unique electrical properties of this power switching device. Basic differences between the HIGBT and the conventional lateral IGBT reflected by measurements of on-state conductance, transient turn-off time, and latchup current are explained and shown to be critically dependent on the structural geometry of the device. Also, a previously unacknowledged mode of operation of the HIGBT is demonstrated. >