Patent ID: 11894426
Assignee: FUJI ELECTRIC CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 16:
17. A semiconductor device comprising:
a semiconductor substrate including a bulk donor; and
a first buffer region of a first conductivity type, the first buffer region being provided on a lower surface side of the semiconductor substrate and having one or more doping concentration peaks and one or more hydrogen concentration peaks in a depth direction of the semiconductor substrate, wherein
a doping concentration at a shallowest concentration peak, out of the doping concentration peaks of the first buffer region, closest to the lower surface of the semiconductor substrate is 50 times as high as a bulk donor concentration of the semiconductor substrate or lower, and
the doping concentration at the shallowest concentration peak, out of the doping concentration peaks of the first buffer region, closest to the lower surface of the semiconductor substrate is 10 times as high as the bulk donor concentration or lower.