Patent ID: 11972950
Assignee: FUJI ELECTRIC CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 8:
9. The semiconductor device according to claim 1, further comprising:
a drift region of an N type that is provided in the semiconductor substrate;
an emitter region that is provided in contact with the upper surface of the semiconductor substrate and that has a higher donor concentration than a donor concentration of the drift region;
a base region of a P type that is provided between the emitter region and the drift region;
a collector region of the P type that is provided in contact with the lower surface of the semiconductor substrate; and
a buffer region of the N type that is provided between the collector region and the drift region and that has one or more donor concentration peaks whose donor concentration is higher than the donor concentration of the drift region,
wherein the first donor concentration peak is the donor concentration peak of the buffer region.