Semiconductor memory device and method of manufacturing semiconductor memory device

A semiconductor memory device, comprising:

• a first conductive layer extending in a first direction within a first layer;
• a first insulating region extending in the first direction within the first layer and adjacent to the first conductive layer in a second direction intersecting the first direction;
• and
• a first pillar extending in a third direction intersecting the first direction and the second direction, dividing the first insulating region, and provided in contact with the first conductive layer;
• wherein:
• the first pillar includes a first portion that divides the first insulating region, and a second portion that includes a part isotropically extending from the first portion toward the first conductive layer within the first layer;
• the first portion includes a first semiconductor layer extending in the third direction and a first insulating film provided on a side surface of the first semiconductor layer;
• the first pillar includes a first region that faces the first portion in the first direction and a second region other than the first region;
• and
• the second portion includes a first conductive film that is in contact with the first insulating film and a second insulating film provided between the first conductive film and the first conductive layer, the second insulating film having a first thickness in a fourth direction parallel to a surface of a substrate and different from each of the first to third directions within the second region and a second thickness in the second direction within the first region, the first thickness being greater than the second thickness.