| 摘要 |
PROBLEM TO BE SOLVED: To prevent insulation breakdown of a gate electrode caused by needle-like projections occurring inside an element isolation trench during the formation of the gate electrode. SOLUTION: After a silicon oxide film 4 is formed on a silicon nitride film 3 which is to serve as an etching mask for forming the element isolation trench, prior to a step of patterning the silicon nitride film 3, with a photoresist film 6 provided with an antireflection film 5 in a lower layer as a mask, the surface of a substrate 1 is cleaned with a hydrofluoric acid-based etchant, to thereby remove (lift off) a foreign matter 7 attached to the surface of the silicon oxide film 4. COPYRIGHT: (C)2011,JPO&INPIT
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