Patent attributes
A semiconductor device includes a stacked body including a plurality of electrode layers stacked with an insulator interposed; a columnar portion provided in the stacked body and extending in a stacking direction of the electrode layers; and a first separation region provided in the stacked body and extending in a first direction. The stacked body includes a memory cell array and a staircase portion arranged in the first direction, the memory cell array including memory cells provided along the columnar portion, and the staircase portion including a plurality of terraces arranged along the first direction. The first separation region includes a first portion and a second portion in the staircase portion, the first portion having a first width in a second direction crossing the first direction, and the second portion having a second width in the second direction. The second width is narrower than the first width.