Patent ID: 8212283

Claim:
Reverse-conducting semiconductor device, comprising: a freewheeling diode and an insulated gate bipolar transistor on a common wafer, part of which wafer forms a base layer of a first conductivity type with a first doping concentration and a base layer thickness, wherein: the insulated gate bipolar transistor has a collector side and an emitter side opposite to the collector side of the wafer; the base layer has a base layer thickness which is a maximum vertical distance between the collector side and emitter side of that part of the wafer with the first doping concentration; a first layer of the first conductivity type having a higher doping concentration than the first doping concentration and a second layer of a second conductivity type are alternately arranged on the collector side; a third layer of the first conductivity type, a fourth layer of the second conductivity type and an electrically conductive fifth layer formed as a gate electrode are arranged on the emitter side; the first layer includes at least one first region, wherein each first region has a first region width; the second layer includes at least one second region, wherein each second region has a second region width, and at least one third region, wherein each third region has a third region width; the first, second and third regions each including a respective region area which is surrounded by a region border; a shortest distance is a minimum length between a point within said region area of a region and a point on said region border; and each region width of a given region is defined as two times a maximum value of any shortest distance within said given region; an electrically active region, which active region is an area within the wafer, which includes and is arranged below the third layer, fourth layer and fifth layer, wherein: each third region area is an area in which any two first regions have a distance larger than two times the base layer thickness, the at least one second region being that part of the second layer which is not the at least one third region; the at least one third region is arranged in a central part of the active region such that there is a minimum distance between the third region border to the active region border of at least the base layer thickness; a sum of the areas of the at least one third region is between 10% and 30% of the active region; and each first region width is smaller than the base layer thickness.