Three dimensional semiconductor device and method of manufacturing the same

Abstract

A semiconductor memory device includes first through structures on a substrate, the first through structures arranged in a first direction, an electrode adjacent to the first through structures and extending horizontally in the first direction along the first through structures, and a ferroelectric layer interposed between the electrode and the first through structures. Each of the first through structures includes a first conductive pillar and a second conductive pillar spaced apart from each other in the first direction, a channel layer extending from a sidewall of the first conductive pillar to a sidewall of the second conductive pillar, the channel layer interposed between the ferroelectric layer and the first and second conductive pillars, the first and second conductive pillars being spaced apart from each other in the first direction and defining a first air gap. Adjacent ones of the first through structures define a second air gap.