MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To make a silicon oxide film offset to a silicon nitride film without changing the thickness of a silicon nitride film in isolation of a semiconductor device and perform thermal oxidation for a silicon substrate while restraining influence of stress of a silicon nitride film. SOLUTION: After a silicon oxide film 2 and a silicon nitride film 3 are formed by lamination on a silicon substrate 1, the silicon nitride film 3 is etched by using a resist pattern 4 as a mask. The silicon oxide film 2 of an irradiated part is removed by casting radioactive rays 6. After a groove 7 for isolation is formed by etching the silicon substrate 1 by using the silicon oxide film 2 as a mask, an upper end 71 of the groove 7 is rounded by oxidation by thermally oxidizing the silicon substrate 1.