SEMICONDUCTOR ELEMENT FOR SWITCHING PURPOSES

摘要

A semiconductor device comprises a semiconductor element divided transversely into at least four zones which alternate in conductivity type. A control electrode is applied to a neighboring inner zone where this zone reaches to the outer surface of one of the outer zones through a perforation in the latter and metallizing is applied to this same surface but set back from the control electrode. The same outer zone has other perforations distributed therein and the neighboring inner zone extends as far as the metallizing. The perforations in the region of the vicinity of the control electrode are connected to the metallizing by a ring-shaped metallic layer which serves to short circuit the neighboring inner zone to the outer zone and also, upon a flow of anode current after firing, due to its relatively high resistance establishes a voltage drop sufficient for firing to spread rapidly at least regionally across the region of the outer zone not covered by metallizing.