A semiconductor device includes transistor cells and enhancement cells. Each transistor cell includes a body zone that forms a first pn junction with a drift structure. The transistor cells may form, in the body zones, inversion channels when a first control signal exceeds a first threshold. The inversion channels form part of a connection between the drift structure and a first load electrode. A delay unit generates a second control signal which trailing edge is delayed with respect to a trailing edge of the first control signal. The enhancement cells form inversion layers in the drift structure when the second control signal falls below a second threshold lower than the first threshold. The inversion layers are effective as minority charge carrier emitters.