| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device wherein the breakdown strength at an element peripheral part is higher than that at a drift part while avalanche resistance amount is improved without a guard ring or field plate. SOLUTION: Related to a vertical MOSFET, a breakdown-strength structure part (element peripheral part) 2 has a second parallel pn structure where a vertical n-type region 2a and a vertical p-type region 2b are alternately jointed repeatedly. The structure 2 is present between a surface and a drain layer 11 around a vertical drift part 1 of first parallel pn structure, and is almost non-electric path region in an on-state and is depleted in an off-state. A third parallel pn structure is provided at a directly-below part 3 of a gate taking-out electrode. |
