A semiconductor memory includes metallic lines on a substrate and including an uppermost metallic line, a semiconductor conduction line on the uppermost metallic line, a vertical structure penetrating the semiconductor conduction line and metallic lines, and including a vertical structure that includes an upper channel film, a first lower channel film, and an upper connection channel film connecting the upper channel film and the first lower channel film between a bottom of the semiconductor conduction line and a bottom of the uppermost metallic line, and a first cutting line through the metallic lines and the semiconductor conduction line, and including a first upper cutting line through the semiconductor conduction line, and a first lower cutting line through the plurality of metallic lines, a width of the first upper cutting line being greater than a width of an extension line of a sidewall of the first lower cutting line.