| 摘要 |
PURPOSE:To improve the reliability without impairing high integration degree by keeping an anti-inversion layer apart from an impurities diffused layer for high voltage resisting elements when a field oxide film is formed on a semiconductor substrate through the layer. CONSTITUTION:A thin SiO2 film 16 and an Si3N4 film 17 are laminated on a p type Si substrate 11 and undergoes a patterning to remove all but only leaving sections on a high voltage resisting element section A and a normal voltage section B. Only the laminated films on the high voltage resisting element section A are surrounded with an ion resisting injected mask made up of a resist or the like and B ion is injected to form p<+> type antiinversion layers 13 on a field region in the exposed section of the substrate 11. Then, after removal of the mask 17, a field oxide film 12 is provided by high temperature oxidation and the pattern is removed from the laminated films so that n<+> type regions 14a and 14b are respectively diffused into the high voltage resisting element section A and the normal voltage section B sandwitched by the layers 13. In this manner, in the element section A, the region 14a is kept apart from the antiinversion layer 13. |
