Patent ID: 8648385

Claim:
A semiconductor device comprising: a semiconductor substrate with a first surface and a second surface, the semiconductor substrate having an element region including an IGBT region and a diode region located adjacent to the IGBT region; an IGBT element formed in the IGBT region, the IGBT element having an emitter electrode on the first surface side, a gate electrode on the first surface side, and a collector electrode on the second surface side; a diode element formed in the diode region, the diode element having a first semiconductor region of first conductivity type on one of the first surface side and the second surface side and a second semiconductor region of second conductivity type on the other of the first surface side and the second surface side; a heavily doped region of first conductivity type located on the first surface side around the element region; an absorption region of first conductivity type located on the second surface side around the element region; and a third semiconductor region of second conductivity type located on the second surface side around the element region, wherein the third semiconductor region is arranged in an irregular pattern.