| 摘要 |
PURPOSE: To reduce a substrate resistance and to improve latch-up resistance, by providing a second channel stop layer where a first impurity is doped higher than the first impurity concentration of a first channel stop layer in a semicon ductor substrate in contact with the lower surface of a field oxide film layer away from an element formation region in side direction by a certain distance. CONSTITUTION: A highly concentrated P<++> second channel stop layer 8 is formed in a semiconductor substrate 1 in contact with the lower surface of a field oxide film 3 in the element separation region of an NMOS semiconductor device, where the second channel stop layer 8 is formed away from the element region by a specific distance, for example, approximately 2-4μm. Also the impurity concentration of the second channel stop layer 8 is at least approximately 10<2> times larger than the impurity concentration of the first channel stop layer 2 of P<+> . |
