| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device for reducing reference between the first wells by improving an isolation breakdown voltage between the first wells, and also to provide a method of manufacturing the device. SOLUTION: The semiconductor device includes: the first conductivity type semiconductor substrate 1; the second conductivity type first wells 2, 3 arranged at prescribed interval on the front layer of the semiconductor substrate 1; the first conductivity type second well 4 arranged between the first wells 2, 3 on the front layer of the semiconductor substrate 1 and having an impurity concentration higher than that of the semiconductor substrate; the first conductivity type third well 5 arranged in the semiconductor substrate 1 and in at least the lower region of the second well 4, and having the impurity concentration higher than that of the semiconductor substrate 1 and lower than that of the second well 4; and the first conductivity type fourth well 11 arranged in the semiconductor substrate 1 and in at least the lower region of the third well 5, and having the impurity concentration higher than that of the semiconductor substrate 1 and lower than that of the second well 4. COPYRIGHT: (C)2010,JPO&INPIT |
