VERTICAL MEMORY DEVICE WITH BIT LINE AIR GAP

摘要

A structure includes a three-dimensional semiconductor device including a plurality of unit device structures located over a substrate. Each of the unit device structures includes a semiconductor channel including at least a portion extending vertically along a direction perpendicular to a top surface of the substrate, and a drain region contacting a top end of the semiconductor channel. The structure also includes a combination of a plurality of contact pillars and a contiguous volume that laterally surrounds the plurality of contact pillars. The plurality of contact pillars is in contact with the drain regions, and the contiguous volume has a dielectric constant less than 3.9.