Vertical semiconductor device with lower pattern comprising silicon and germanium

Abstract

A vertical semiconductor device may include a substrate, a pattern structure on the substrate, and a channel structure in a channel hole passing through the pattern structure. The pattern structure may include insulation patterns and gate structures alternately stacked in a vertical direction perpendicular to an upper surface of the substrate. The channel structure may extend in the vertical direction. The channel structure may include a data storage structure on an inner surface of the channel hole, a channel contacting the data storage structure, a lower pattern on the channel positioned at a lower portion of the channel hole, and a filling insulation pattern on the channel and the lower pattern. The channel may have a cylindrical shape. The lower pattern may include an oxide including silicon and germanium.