Semiconductor components of this type, be they thyristors or diodes, for example, are generally known. The semiconductor body of a thyristor generally possesses four zones of alternate opposite conductivity type, and a pn-junction in each case lies between these zones. The pn-junction located between the outer and the inner anode-side zone is referred to as a blocking-pn-junction, since the greatest part of the blocking voltage occurs across it. The semiconductor body of a power diode basically possesses two zones of opposite conductivity type. The semiconductor bodies of such semiconductor components generally possess a specific content of recombination centers, which decisively influence their electric properties, for example the turn-off time. The aforementioned recombination centers are generally heavy metal atoms, such as gold, platinum or manganese.
The processes which are employed in the production of the above-mentioned semiconductor components involve the gettering of a specific part of the introduced recombination centers into regions close to the surface. The gettering layers are, for example, highly doped zones, in particular zones doped with boron or phosphorus, or also zones close to the surface, whose crystal lattice structure is heavily disturbed by mechanical processing. As a result of the gettering, there is a reduction in the concentration of the recombination centers beneath the gettering layer close to the surface. If uniformly gettered layers are present both at the anode side and at the cathode side, the curve of the concentration of the recombination centers over the thickness of the semiconductor body has a U-shaped, symmetrical profile. If, on the other hand, a weaker gettering effect exists at the anode side than at the cathode side, for example, due to less disturbance of the surface, the concentration of the recombination centers is higher at the anode side than at the cathode side.
The absolute degree of the concentration of the recombination centers can be set by the quantity of the diffused-in recombination centers, for example, of gold atoms. The symmetry of the profile of the concentration of the recombination centers cannot in practice be effectively influenced either by controlling the quantity of the recombination centers or by controlling the diffusion parameters during the diffusing-in of the recombination centers.