Semiconductor devices including flared source structures

Abstract

A semiconductor device includes a structure including gate electrodes and interlayer insulating layers alternately stacked on an upper surface of a substrate, trenches passing through the structure; and a groove passing through a portion of the structure. The gate electrodes include word lines, and first and second select lines. The word lines are stacked in a vertical direction upwardly from the upper surface of the substrate. The first and second select lines are on the word lines, and are spaced apart from each other in a first horizontal direction parallel to the upper surface of the substrate. The trenches include a first trench and a second trench spaced apart from the first trench. The groove is on the word lines. The groove and a portion of the first trench are between the first select line and the second select line. The second trench is spaced apart from the select lines.