SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

A semiconductor device may include a gate structure, a source structure that is disposed on the gate structure, channel structures that extend into the source structure through the gate structure and include a channel layer and a memory layer surrounding the channel layer, the memory layer including a cut area that exposes the channel layer, and a slit structure that extends into the source structure through the gate structure between the channel structures, an upper surface of the slit structure being disposed at a lower level than the cut area.