Semiconductor memory device

A semiconductor memory device comprising:

• a stacked body including a plurality of conductive layers stacked apart from each other, the stacked body having a step portion where the plurality of conductive layers is processed in a step-like shape;
• a plurality of first contacts arranged in a partial region of the step portion at least on one line in a first direction intersecting with a stacking direction of the stacked body, the plurality of first contacts being respectively connected with the plurality of conductive layers;
• a pillar extending in the stacking direction in the stacked body deviated from the step portion, the pillar forming a memory cell at a respective intersection with at least a part of the plurality of conductive layers;
• a plurality of columnar portions arranged in the step portion to form a plurality of arrays each extending in the first direction, the plurality of columnar portions extending in the stacking direction;
• and
• first and second plate-like portions extending in the stacking direction and the first direction in the stacked body including the step portion, the first and second plate-like portions being apart from each other in a second direction intersecting with the stacking direction and the first direction, the first and second plate-like portions dividing the stacked body in the second direction, wherein
• the step portion includes:
• a first step portion that is arranged on one end in the first direction of the stacked body, the first step portion including a first region between the first and second plate-like portions, and
• a second step portion that is arranged on another end in the first direction of the stacked body, the second step portion including a second region between the first and second plate-like portions,
• the plurality of first contacts is selectively arranged in the first region among the first and second regions facing each other in the first direction,
• the plurality of columnar portions includes:
• a plurality of first columnar portions including a first insulating layer, the plurality of first columnar portions having a layer structure different from that of the pillar, and
• a plurality of second columnar portions having a same layer structure as that of the pillar,
• in the second region, a first group including at least a part of the plurality of second columnar portions is arranged in a dispersed manner on first arrays among the plurality of arrays, and
• in the first region, a second group including at least a part of the plurality of first columnar portions is arranged on at least one array proximal to an array position of the plurality of first contacts, among second arrays facing the first arrays in the first direction.