THE MODIFIED STRUCTURE OF THE LATERAL IGBT ON THE SOI WAFER FOR IMPROVING THE DYNAMIC LATCH-UP CHARACTERISTICS

In this brief, the modified structure of the lateral IGBT(LIGBT) on th e SOI wafer for improving the dynamic latchup characteristics is prese nted with its numerical simulations and experimental results. The modi fied LIGBT structure has a p(+)-emitter lever between the collector an d gate regions. The current at which the latch-up occurs during the tu rn-off transient under an inductive load is estimated in comparison wi th that of the conventional LIGBT. The dynamic latch-up current at R.T . and 125 degrees C for the modified LIGBT were 350 A/cm(2) and 290 A/ cm(2), respectively. These results indicate the improvement of about 3 .5 times at R.T. and about 5.5 times at 125 degrees C compared with th ose for the conventional LIGBT. This remarkable improvement in the dyn amic latch-up performance is accomplished at the expense of an increas e of 0.8 V in the forward voltage drop.