Patent ID: 7678641

Claim:
A method of fabricating a semiconductor device, comprising the steps of: forming a device isolation trench in a silicon substrate while using an SiN pattern as a mask; forming, after said step of forming said device isolation trench, a silicon oxide film in said device isolation trench to cover said SiN pattern; removing a part of said silicon oxide film located above said SiN pattern by a polishing process; removing, after said polishing process, a part of said silicon oxide film in said device isolation trench while leaving said silicon oxide film on a bottom part of said device isolation trench; depositing, after said step of removing a part of said silicon oxide film in said device isolation trench, an HF resistant film comprising SiOCN or SiCN so as to cover said silicon oxide film left on said bottom part of said device isolation trench and to fill at least a top part of said device isolation trench and so as to cover said SiN pattern; and removing said SiN pattern and said HF-resistant film on said SiN pattern, such that said HF-resistant film has a top surface flush to or above a top surface of said silicon substrate.