Patent ID: 7785984

Claim:
A manufacturing method for a semiconductor device comprising: generating on a substrate liquid-phase silanol having fluidity by causing a source gas made of a material containing silicon to react with a source gas made of a material containing oxygen, introducing the silanol into a first recess until the first recess is filled with the silanol, the first recess having an aspect ratio of a predetermined value or more in a plurality of recesses provided in the substrate and having different aspect ratios, and introducing the silanol into a space from a bottom to an intermediate portion in a second recess while an inner side-face portion is covered with the silanol, the second recess having an aspect ratio lower than the predetermined value in the recesses; burying a silicon oxide film in the whole of the first recess and providing the silicon oxide film from the bottom to the intermediate portion in the second recess while the inner side-face portion thereof is covered with the silicon oxide film, by converting the silanol introduced into the first and second recesses into the silicon oxide film by dehydrating condensation; providing a dielectric film on the silicon oxide film until the dielectric film is buried from the intermediate portion to an upper portion in the second recess in which the silicon oxide film is provided, the dielectric film having film density higher than that of the silicon oxide film; wherein the first recess is formed by digging down a memory cell forming region at least from a floating gate electrode film to a superficial portion of a semiconductor substrate while forming the second recess in a region except for the memory cell forming region, the second recess having substantially the same depth as the first recess and a width greater than that of the first recess, the memory cell forming region including the semiconductor substrate, a tunnel dielectric film provided on the semiconductor substrate, and the floating gate electrode film provided on the tunnel dielectric film; providing a stopper film on the floating gate electrode film, the first and second recesses being formed by digging down films from the stopper film to the superficial portion of the semiconductor substrate, and removing the silicon oxide film and the dielectric film which are provided above the stopper film after the silicon oxide film and the dielectric film are buried in the first and second recesses; and retreating the silicon oxide film in the first recess, the silicon oxide film and the dielectric film in the second recess, and the dielectric film to an intermediate portion in a thickness direction of the floating gate electrode film.