| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device and a method of manufacturing the same wherein lateral diffusion of well is small, punch-through between the source/drain diffusion layer, in the well, of transistor formed in the well and the external well can be protected and moreover the number of steps of manufacturing is not increased. SOLUTION: This semiconductor device comprises a semiconductor substrate 10 of a first conductivity type, a first wells 20a, 20b of second conductivity types formed in a first region of the main surface of the semiconductor substrate 1, a second well 22a of the first conductivity type formed in the second region which is different from the first region of the main surface of the semiconductor substrate 10, a third well 22b of the first conductivity type formed in the first well and a high concentration impurity layer 26 of the first conductivity type formed in the third well region and also in the semiconductor substrate isolated from the semiconductor substrate surface in the element region.
|
