Patent attributes
A stacked film of a first insulation film being a silicon oxide film with an extremely low moisture content, and a second insulation film being a silicon oxide film with a higher moisture content than the first insulation film, therefore, with a low in-plane film thickness distribution rate is formed, and this is polished by CMP. Polishing is performed until the second insulation film is wholly removed directly above a ferroelectric capacitor structure and a surface of the first insulation film is exposed to some extent. At this time, surface flattening is performed for a top surface of a first portion in the first insulation film and a top surface of the second insulation film, and an interlayer insulation film constituted of the first insulation film and the second insulation film remaining on a second portion of the first insulation film is formed.
