Patent ID: 8592887

Claim:
A semiconductor storage device, comprising: a semiconductor substrate; a plurality of device areas formed in the semiconductor substrate, the device areas being spaced from one another in a first direction and extending along a second direction orthogonal to the first direction; first and second select gate electrodes formed in a first device area of the device areas via a gate insulating film, the select gate electrodes being aligned in the second direction so as to form a pair; a plurality of memory cell gate electrodes formed in the first device area via the gate insulating film, the memory cell gate electrodes being aligned in the second direction with a first spacing and located adjacent to the first select gate electrode so as to be on an opposite side of the second select gate electrode; an interlayer insulating film formed in a first region between adjacent pairs of select gate electrodes, the interlayer insulating film having a sidewall spaced from one of the select gate electrodes by a second spacing greater than the first spacing; a first fill material formed in the first region and a second region between the memory cell gate electrodes, wherein the first fill material extends along upper portions of the memory cell gate electrodes in the second region so as to cover air gaps residing between the memory cell gate electrodes, and wherein the first fill material extends along a sidewall of the first select gate electrode and the sidewall of the interlayer insulating film in the first region, thereby defining a recess above the first fill material formed along the sidewall of the first select gate electrode and the sidewall of the interlayer insulating film; a second fill material formed above the first fill material and extending into a gap located between the sidewall of the first select gate electrode and the sidewall of the interlayer insulating film so as to fill the recess, and between the first select gate electrode and one of the memory cell gate electrodes; a nitride film formed above the second fill material; an upper interlayer insulating film formed above the nitride film; and a plurality of contacts formed through the upper interlayer insulating film, the nitride film, and the interlayer insulating film, the contacts physically contacting each of the device areas.