Patent ID: 7868376

Claim:
A semiconductor storage device comprising: a semiconductor substrate; a plurality of word lines formed with a predetermined interval on the semiconductor substrate; a selection transistor provided at an end portion of the plurality of word lines; a first insulating film formed so as to cover side surfaces of the word lines, a side surface of the selection transistor, and a surface of the semiconductor substrate between the word lines; a high-permittivity film formed on the first insulation film, the high-permittivity film including a metal oxide and having a higher permittivity than the first insulating film; a second insulating film formed so as to cover the upper surface of the word lines and the selection transistor; a first air-gap portion located between the word lines and surrounded by the high-permittivity film and the second insulating film; and a second air-gap portion formed via the first insulating film and the high-permittivity film at a sidewall portion, which opposes the selection transistor, of the word line adjacent to the selection transistor, an upper portion of the second air-gap portion being covered by the second insulating film.