Patent ID: 6881646

Claim:
A process for producing a semiconductor device, which comprises the following steps: a step of forming a first oxide film on a circuit forming side of a semiconductor substrate by a first oxidizing process of the semiconductor substrate, a step of forming an anti-oxidation film on the first oxide film, a step of forming a photoresist film on the anti-oxidation film, a step of removing a portion of the photoresist film, a step of removing portions of the anti-oxidation film and the first oxide film, a step of trenching a groove on the semiconductor substrate in a portion of the semiconductor substrate from which the first oxide film is removed, a step of removing another portion of the photoresist film on the antioxidation film, a step of forming a space by recessing the first oxide film to an extent of 5 nm to 40 nm from an element isolation region, a step of forming a second silicon oxide film in the space and on an inside wall of the groove by a second oxidizing process of the semiconductor substrate, wherein the radius of curvature of the semiconductor substrate around an upper edge of the groove is 3 nm or more, a step of embedding an element isolation film on the second oxide film in the groove, a step of removing the anti-oxidation film and the first oxide film on the semiconductor substrate, and a step of forming a gate dielectric film and a gate electrode on a portion of the semiconductor substrate from which the first oxide film is removed.