A semiconductor device includes a semiconductor body having first and second opposite surfaces along a vertical direction, and an active diode area. The active diode area includes: a p-doped anode region adjoining the first surface; an n-doped drift region between the anode region and the second surface; an n-doped cathode contact region adjoining the second surface; a p-doped injection region adjoining the second surface and the cathode contact region; and a p-doped auxiliary region between the drift region and the cathode contact region. The auxiliary region includes first and second sub-regions. In a top view, the first sub-region covers at least part of the injection region and the second sub-region covers at least part of the cathode contact region. In the top view, the auxiliary region includes a plurality of openings covering from 0.1% to an 20% of a surface area of the active diode area at the second surface.