THYRISTOR

A semiconductor component such as a four layer assymetrical thyristor having four zones of alternately opposite conductivity type, including a P emitter, an N base, a P base and an N emitter, wherein in the N base zone there is provided a stopping layer in a partial region adjacent the P emitter. The stopping layer has a doping concentration which decreases in a direction towards the P emitter zone perpendicular to the four zones. Thus the transport factor for the holes injected by the P emitter is desirably changed by means of lowering the doping concentration of the stopping layer in front of the P emitter, on the side of the anode, of a highly blocking thyristor in the forward direction, while the full effectiveness of the stopping layer remains unchanged. Also a lower blocking current in the blocking condition and/or a lower transmission voltage in the passing condition is attained.