Abstract: A semiconductor device includes; cell transistors on a substrate, lower electrodes respectively connected to the cell transistors, arranged according to a first pitch in a first horizontal direction, and extending in a vertical direction, and an etching stop layer surrounding lower sidewalls of the lower electrodes and arranged at a level higher than a level of the cell transistors, wherein the etching stop layer includes a first portion vertically overlapping the lower electrodes and a second portion laterally surrounding the first portion, and the second portion includes recesses arranged according to a second pitch in the first horizontal direction.