MEMORY DEVICE AND METHOD OF MANUFACTURING THE SAME

A memory device includes a substrate and a plurality of word lines. The word lines are disposed on the substrate. The word lines extend in the first direction and are arranged in the second direction. The first direction intersects the second direction. The memory device further includes a first sub-select gate extending in the first direction and separated from the outermost word line in the second direction. One end of the first sub-select gate has a first width in the second direction. The major portion of the first sub-select gate has a second width in the second direction. The second width is greater than the first width.