Patent ID: 11901419
Assignee: FUJI ELECTRIC CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 16:
17. A manufacturing method of a semiconductor device, comprising:
implanting hydrogen ions from one of an upper surface and a lower surface of a semiconductor substrate to a first depth position, and implanting hydrogen ions from the other one of the upper surface and the lower surface of the semiconductor substrate to a second depth position different from the first depth position; and
performing heat treatment on the semiconductor substrate, wherein
the second depth position is disposed between the first depth position and the other one of the upper surface and the lower surface,
wherein the semiconductor substrate includes a drift region of a first conductivity type, a trench portion provided in the upper surface of the semiconductor substrate, and a buffer region of the first conductivity type provided between the drift region and the lower surface of the semiconductor substrate and having a higher concentration than the drift region, and
wherein the first depth position and the second depth position are disposed between a lower end of the trench portion and an upper end of the buffer region in a depth direction of the semiconductor substrate.