| 摘要 |
PURPOSE:To optimize trigger sensitivity and turn-off losses by providing a layer resistance for a low resistance buffer layer to be formed on a first emitter layer so that a certain relation is satisfied between such layer resistance and a gap of a shortcircuit section. CONSTITUTION:A gate turn-off thyristor (GTO) comprises a high resistance first base layer 2 of the second conductivity type and a second base layer 3 of the first conductivity type on a first emitter layer 1 of the first conductive type while interposing a low resistance buffer layer 8 of the second conductivity type therebetween: a plurality of divided second emitter layers 4 of the second conductivity type on said base layers to form first and second main electrodes 6, 5 which are in contact with the first emitter layer 1 and the second emitter layer 4, respectively, and a gate electrode 7 which is in contact with the second base layer 3; and a shortcircuit section 9 which is in contact with the first main electrode 5 at a region where a part of the buffer layer 8 is made to expose to the surface of the first emitter layer 1. In such a GTO, parameters are so preset that a relation, rhos=K1/d<2>, where 10<-2=K<=10<6>, is satisfied with the gap for the shortcircuit section 9 being equal to d cm, and the layer resistance of the buffer layer 8 to rhos OMEGA/square. |
