A new lateral anode switched thyristor (LAST) with current saturation and low turn-off time

Abstract

A novel MOS-gate controlled thyristor, entitled lateral anode switched thyristor (LAST), which exhibits a high current saturation and a low turn-off time, is proposed and successfully fabricated. Experimental results show that the new LAST achieves a current saturation capability larger than 1200 A/cm/sup 2/ even at high anode voltages. The forward voltage drop of LAST is 1.2 V at 100 A/cm/sup 2/ where 10 V was biased to the dual gates. The turn-off time of LAST without any lifetime-control process is 1.5 /spl mu/s while that of LAST without p/sup +/ diverter is about 2.9 /spl mu/s. Our experimental data indicates that the p/sup +/ diverter successfully diverts holes in the drift region during the turn-off and a turn-off time is considerably decreased in the proposed LAST. The LAST, where any trouble-some parasitic thyristor mechanism is eliminated, completely suppresses a latch-up and increases the maximum controllable current considerably.