SEMICONDUCTOR DEVICE AND MANUFACTURE THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device in which a high-voltage driving element and a low-voltage driving element can be formed on the same chip. SOLUTION: P-type buried layers 12 and N<+> -type buried layers 14 are formed at different levels in a semiconductor substrate 10 so that the layers 12 can become higher in level and epitaxial layers 13 and 15 are respectively formed on the buried layer 12 and 14. Then the surfaces of the epitaxial layers 13 and 15 are flattened and separating areas 32 are formed on the buried layers 12 near the boundaries between the buried layers 12 and 14. Finally, sink areas 42 are formed on the buried layers 14.