| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a semiconductor device having elements superior in withstand voltage which are formed at a peripheral element region, without complicating the production process. SOLUTION: Impurity ions are implanted in a substrate 11 to form first wells 14, a field oxide film 19 is formed on the surface of the substrate, including the surfaces of the wells 14 to section active regions 20, and impurity ions are implanted in the wells 14 to form second wells 22 having active regions 20 which form memory array regions 20a and peripheral element regions 20b. Regions corresponding to the regions 20a, 20b are exposed. A mask 23 is formed to cover other regions than the exposed regions. Channel stop ions 24a, 24b are implanted in the second wells 22 through the mask 23 at an energy enough to pass through the field oxide film 19. |
