Patent ID: 8604584

Claim:
A semiconductor device comprising: a substrate of a first conduction type, the substrate having a first main surface, a second main surface and a concave portion formed on the second main surface; a front surface element structure provided on the first main surface of the substrate; a first semiconductor region of a second conduction type formed at a side end of the front surface element structure, the concave portion extending from the second main surface of the substrate to the first semiconductor region; and a second semiconductor region of the second conduction type disposed on the second main surface of the substrate and being electrically connected to the first semiconductor region, wherein the first semiconductor region includes a cleavage plane, an entire portion of the cleavage plane between a boundary, which is an intersection of a bottom wall of the concave portion and a side wall of the concave portion, and an intersection of the cleavage plane and the first main surface of the substrate, being in the first semiconductor region.