Abstract: A semiconductor switching device according to the invention has a semiconductor crystal comprising sequentially alternate layers of opposite conductivity type. The device comprises two emitters of different conductivity type, at least one gate base, another base of opposite conductivity type with respect to the first base adjacent to the gate base, and an additional region of conductivity type opposite to the gate base which is adjacent to the surface of the gate base and arranged completely or partially in the gate base. At a point where the additional region extends onto the surface, there is provided a recess the bottom area of which exceeds that of the exposed part of the additional area, so that this part is disposed within the bottom area of the recess without contacting the lateral walls of the recess.

Abstract: A semiconductor indicating instrument or display device employing a silicon carbide crystal having a first ohmic contact with an n-type region and at least one second ohmic contact with a p-type region. Another region is disposed between the regions of opposite types of conductivity. The silicon carbide crystal also has an additional region with structure defects which are clusters with a concentration of 10.sup.19 cm.sup.-.sup.3 to 10.sup.22 cm.sup.-.sup.3, that region adjoining the second ohmic contact and having a thickness greater than that of the p-type region by at least 0.05 mu.