SEMICONDUCTOR MEMORY DEVICE AND METHOD OF FABRICATING THE SAME

A semiconductor memory device includes a stack structure including word lines and interlayer dielectric patterns that are alternately and repeatedly stacked on a semiconductor substrate. Semiconductor patterns are respectively disposed between vertically adjacent word lines. A bit line vertically extends from the semiconductor substrate and contacts the semiconductor patterns. A capping insulating pattern is disposed between the bit line and the word lines and covers side surfaces of the interlayer dielectric patterns. Memory elements are respectively disposed between vertically adjacent interlayer dielectric patterns. Each of the semiconductor patterns comprises a first source/drain region that contacts the bit line, a second source/drain region that directly contacts one memory element of the memory elements, and a channel region between the first and second source/drain regions. A largest width of the first source/drain region is greater than a width of the channel region.