BIPOLAR SWITCHING TRANSISTOR WITH REDUCED SATURATION

摘要

The invention relates to a bipolar switching transistor, comprising a highly doped emitter region (4) with n-conductivity, a base region (3) with p-conductivity, said base region (2) being sequential to said emitter region, a slightly doped collector region (1) with n-conductivity sequential to said base region and a highly doped collector region with n-conductivity which follows said slightly doped collector region. The lifetime of the minority charge carriers in the base (3) and in the area of the slightly doped collector region (2) is very high up to the area close to the n<->n<+> junction. The aim of the invention is to provide a switching transistor for higher blocking voltages which is itself able to prevent high degrees of saturation and which presents only small losses when switched off from a status with a low collector current or a high base current. To this end, a recombination layer (5) is provided inside the slightly doped collector (2) region in the area of the boundary layer with the highly doped collector region (1). The lifetime of the minority charge carriers in said recombination layer is at least two powers of ten less than that in the slightly doped collector region (2).