A semiconductor memory device according to an example embodiment of the present inventive concept may include: a plurality of lower electrodes located on a substrate and spaced apart from one another; and an etch stop pattern located on the substrate and surrounding at least a part of each of the plurality of lower electrodes, in which the etch stop pattern includes: a first etch stop pattern including carbon; and a second etch stop pattern located on the first etch stop pattern and including a material different from a material of the first etch stop pattern.