A semiconductor device includes an IGBT cell including a second-type doped drift zone, and a desaturation semiconductor structure for desaturating a charge carrier concentration in the IGBT cell. The desaturation structure includes a first-type doped region forming a pn-junction with the drift zone, and two portions of a trench or two trenches arranged in the first-type doped region and beside the IGBT cell in a lateral direction. Each of the two trench portions or each of the two trenches has a wide part below a narrow part. The wide parts confine a first-type doped desaturation channel region of the first-type doped region at least in the lateral direction. The narrow parts confine a first-type doped mesa region of the first-type doped region at least in the lateral direction. The desaturation channel region has a width smaller than the mesa region in the lateral direction, and adjoins the mesa region.