Semiconductor memory device and method for manufacturing the same

A method for manufacturing a semiconductor memory device comprising:

• forming a first electrode member on a flat surface perpendicular to a first direction,
• forming a second electrode member parallel to the first electrode member,
• forming a memory hole that penetrates the first electrode member and the second electrode member in the first direction,
• forming a first insulating member on a side surface of the memory hole, and
• forming a second insulating member by oxidizing a surface of the first insulating member.

A semiconductor memory device comprising:

• a substrate;
• a stacked body including a plurality of electrode members and a plurality of insulating members, each of the electrode members and each of the insulating members being stacked alternately in a first direction on the substrate;
• a memory hole that extends in the stacked body in the first direction;
• a semiconductor member that is disposed to extend in the memory hole in the first direction;
• and
• a memory member that is disposed between the semiconductor member and the plurality of electrode members,
• the plurality of electrode members including a first electrode member and a second electrode member,
• a width of the memory hole of a direction perpendicular to the first direction in a plane including the first direction at a position of the first electrode member being smaller than a width of the memory hole of a direction perpendicular to the first direction in a plane including the first direction at a position of the second electrode member, and
• a thickness of the memory member at the position of the first electrode member being greater than a thickness of the memory member at the position of the second electrode member.