MANUFACTURING METHOD FOR SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To form isolation having a high size precision while preventing a cost increase and degrading of a yield by additionally forming a reflection preventing film for an exclusive lithography purpose. SOLUTION: A silicon oxide film 102 having a film thickness of over 10 nm and below 30 nm and a silicon nitride film 103 (an Si3N4 film is preferable) having a film thickness of over 70 nm and below 85 nm are applied on an Si substrate and additionally a Si trench isolation is formed by performing a lithography step without forming another reflection preventing film. The isolation region (the electric isolating layer) having a high size precision can be formed by the simple step.