Patent ID: 8617936

Claim:
Method for manufacturing a reverse-conducting semiconductor device, which includes a freewheeling diode and an insulated gate bipolar transistor on a common wafer, the method comprising: providing the wafer, part of which wafer having an unamended doping in a finalized device forms a base layer, wherein the insulated gate bipolar transistor includes an emitter side and a collector side, in which the wafer of a first conductivity type with a first side and a second side opposite the first side is provided, the first side forming the emitter side and the second side forming the collector side of the insulated gate bipolar transistor, creating a first layer of the first conductivity type or of a second conductivity type on the second side of the wafer by implantation, creating a mask with at least one opening on the first layer and removing those parts of the first layer, on which an opening of the mask is arranged, the remaining parts of the first layer forming a third layer, implanting ions into the wafer on the second side into those parts of the wafer, on which the at least one opening is arranged and using the mask as a barrier for the ions to form a second layer of a different conductivity type than the third layer, removing the mask and performing annealing for the activation of the second layer, and creating a second electrical contact, which is in direct electrical contact to the second and third layer, on the second side.