Semiconductor memory devices and methods of fabricating the same

A semiconductor memory device includes a first semiconductor chip and a second semiconductor chip. Each semiconductor chip of the first and second semiconductor chips may include a cell array region and a peripheral circuit region. The cell array region may include an electrode structure including electrodes sequentially stacked on a body conductive layer and vertical structures extending through the electrode structure and connected to the body conductive layer. The peripheral circuit region may include a residual substrate on the body conductive layer and on which a peripheral transistor is located. A bottom surface of the body conductive layer of the second semiconductor chip may face a bottom surface of the body conductive layer of the first semiconductor chip.