Semiconductor memory device and method of manufacturing semiconductor memory device

Abstract

There are provided a semiconductor memory device and a method of manufacturing the semiconductor memory device. The semiconductor memory device includes a gate stack comprising a plurality of first interlayer insulating patterns and a plurality of conductive patterns alternately stacked, a dummy stack comprising a plurality of second interlayer insulating patterns and a plurality of sacrificial insulating layers, a plurality of step-shaped grooves defined at different depths in the gate stack, a plurality of openings passing through the dummy stack and spaced apart from each other, a first gap-fill insulating pattern filling the plurality of step-shaped grooves, a second gap-fill insulating pattern filling the plurality of openings, a plurality of conductive gate contacts passing through the first gap-fill insulating pattern and connected to the plurality of conductive patterns, and a plurality of conductive peripheral circuit contacts passing through the second gap-fill insulating pattern.