PURPOSE: To better cooperation between the gate power, di/dt level and dv/dt level by arranging channel sections serving as a section adapted to be initially conducted as several dots in a thyristor designed to be switched off through a reverse bias while switched on upon releasing of bias.
CONSTITUTION: A diffusion is made to form a p+ type anode emitter region 2 on the back of an n- type semiconductor substrate 3 serving as base region, on the side of which an anode electrode 7 is applied. A p type gate region 5 is diffused into the surface of the substrate and an n type emitter region 4 is provided within the region. Then, a cathode electrode 8 is mounted on the region 6 while a circular gate electrode 9 on the periphery of the region 5 to make a thyristor. In such an arrangement, holes are provided concentrically in dots on the surrounding area with one set up in the center covering the part of the region 5 in contact with the region 4. The region 4 is allowed to penetrate the holes through the rear surface thereof so that an n type channel region 41 is produced as a region adapted to be initially conducted.
MURAKAMI SUSUMU
SANBE ISAMU
OIKAWA SABUROU
TERASAWA YOSHIO
