| 摘要 |
PROBLEM TO BE SOLVED: To provide a high voltage semiconductor device in which deterioration of the breakdown voltage can be prevented, even if irregular dimensions exist due to irregularities in impurity concentration and a deviated mask. SOLUTION: In this high voltage semiconductor device, a guard ring layer 11 composed of high concentration impurities is formed inside a RESURF layer 10, and a guard ring layer 12, whose impurity concentration is almost the same as that of the RESURF layer is arranged outside the RESURF layer 10. |
