Semiconductor storage device and semiconductor storage device manufacturing method

A semiconductor storage device comprising:

• a stacked body where a conductive layer and an insulating layer are stacked multiple number of times from a bottom of the stacked body to a top of the stacked body;
• a plate-shaped portion extending along a stacking direction of the stacked body and a first direction intersecting the stacking direction and dividing the stacked body along a second direction intersecting the stacking direction and the first direction;
• and
• a pillar penetrating the stacked body, extending along the stacking direction, and including a core layer, wherein
• a width of the plate-shaped portion in the second direction at the same height as a conductive layer located at the top of the stacked body is larger than a width of the plate-shaped portion in the second direction at the same height as a conductive layer located at the bottom of the stacked body, and
• a width of the core layer in the second direction at the same height as the conductive layer located at the top of the stacked body is smaller than a width of the core layer in the second direction at the same height as the conductive layer located at the bottom of the stacked body.

A semiconductor storage device manufacturing method comprising:

• forming a stacked body where a plurality of first layers and a plurality of second layers are alternately stacked;
• forming a hole penetrating at least a part of the stacked body and extending along a stacking direction of the stacked body by etching the stacked body from a first end side of the stacked body in the stacking direction;
• and
• forming a slit penetrating at least a part of the stacked body and extending along the stacking direction and a first direction intersecting the stacking direction by etching the stacked body from a second end side of the stacked body in the stacking direction, wherein the first end side and the second end side are opposite end sides of the stacked body in the stacking direction.