Patent ID: 11935945
Assignee: FUJI ELECTRIC CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 4:
5. The semiconductor device according to claim 1, wherein
in the N-type region, a ratio κ of an actual bulk-acceptor concentration NAre to a specification value NA0 of the bulk-acceptor concentration is set as κ=NAre/NA0;
a ratio θ of an actual donor concentration NFre to a target value NF0 of a final donor concentration is set as θ=NFre/NF0, an upper limit value of the θ is set as θ+, an lower limit value of the θ is set as θ−, the θ+ is 1.15, and the θ− is 0.85; and
the ratio κ and the upper limit value θ+ and the lower limit value θ− of the θ satisfy a following expression,

(1−θ+)/α′+1≤κ≤(1−θ−)/α′+1

wherein α′=NA0/NF0, NF0 is a target value of a donor concentration of the N-type region.