A gate turn-off thyristor including: an n-type emitter semiconductor layer divided into a plurality of n-type areas; a p-type base semiconductor layer which cooperates with the n-type emitter semiconductor layer to form a first main circular surface; an n-type base semiconductor layer; and a p-type emitter...http://www.google.es/patents/US5554863?utm_source=gb-gplus-sharePatente US5554863 - Gate turn-off thyristor
