Latching in lateral insulated gate bipolar transistors

Abstract

The maximum gate controllable current of several different lateral insulated gate bipolar transistor (LIGBT) structures have been investigated. It is shown that the turn-on gate resistance affects the latching current of LIGBT's because of the faster turn-on of the lateral current component than the vertical current component. Addition of p+ sinker, n+ buried layer and surface shorts on the cathode side to the basic LIGBT are found to increase the maximum controllable current but addition of surface anode shorts degrades it. The effect of using SIPOS and oxide as surface passivation layer on latching are compared. The maximum controllable current of LIGBT's is shown to decrease with increasing temperature, as expected, but the rate of decrease is slower than the vertical IGBT's. P-channel devices are worse in latching performance than the n-channel counterparts.