Semiconductor device

A semiconductor device comprising:

• a semiconductor substrate of a first conductive type, having a first main surface and a second main surface opposite to the first main surface, an IGBT region, a diode region, and a boundary region between the IGBT region and the diode region, being provided along an in-plane direction in the semiconductor substrate;
• an emitter electrode provided on the first main surface of the semiconductor substrate;
• and
• a collector electrode provided on the second main surface of the semiconductor substrate,
• the semiconductor substrate including:
• a first anode layer of a second conductive type and a first contact layer of the second conductive type with a higher concentration of impurities of the second conductive type than the first anode layer, being provided on a first main surface side being a side of the first main surface, in the diode region;
• a cathode layer of the first conductive type provided on a second main surface side being a side of the second main surface, in the diode region;
• a first carrier discharge layer of the second conductive type provided adjacent to the cathode layer in the in-plane direction on the second main surface side in the diode region;
• a second anode layer of the second conductive type and a second contact layer of the second conductive type with a higher concentration of impurities of the second conductive type than the second anode layer, being provided on the first main surface side in the boundary region;
• and
• a collector layer of the second conductive type provided on the second main surface side in the boundary region,
• wherein a concentration of impurities of the second conductive type of the second anode layer is lower than a concentration of impurities of the second conductive type of the first anode layer, or an occupied area ratio of the second contact layer with respect to the area where the emitter electrode is in contact with the semiconductor substrate in the boundary region is smaller than an occupied area ratio of the first contact layer with respect to the area where the emitter electrode is in contact with the semiconductor substrate in the diode region.