p--layer punch-through structure with high concentration p-emitter for a light-triggered thyristor

We studied the on-state voltage reduction of a light-triggered thyristor from the viewpoints of reduced thyristor thickness and realization of a high-injection low-lifetime structure. The reduced thickness was achieved through a p^--layer punch-through structure. The high injection was achieved by a thick, highly-doped p-emitter region. The on-state voltage of a 6-kV 5.5-kA light-triggered thyristor with the p^--layer punch-through structure and with the thick, high concentration p-emitter was reduced by about 0.2 V