Semiconductor memory device and method for manufacturing same

A semiconductor memory device comprising:

• a plurality of electrode layers stacked in a first direction;
• a plurality of interlayer insulating layers provided between the plurality of electrode layers respectively;
• a semiconductor channel body extending in the first direction through the plurality of electrode layers and the plurality of interlayer insulating layers;
• a charge storage layer extending along the semiconductor channel body in the plurality of electrode layers and the plurality of interlayer insulating layers;
• and
• a first insulating layer provided between the charge storage layer and the plurality of electrode layers and between charge storage layer and the plurality of interlayer insulating layers, wherein
• the plurality of interlayer insulating layers includes a first interlayer insulating layer and a second interlayer insulating layer, the first and second interlayer insulating layers being adjacent to each other,
• one of the plurality of electrode layers is positioned between the first interlayer insulating layer and the second interlayer insulating layer,
• the first insulating layer has first to third thicknesses along a direction from the charge storage layer to the one of the plurality of electrode layers, the first thickness being defined between the first interlayer insulating layer and the charge storage layer, the second thickness being defined between the second interlayer insulating layer and the charge storage layer, the third thickness being defined between the one of the plurality of electrode layers and the charge storage layer, and the third thickness being larger than the first thickness and the second thickness,
• the one of the plurality of electrode layer has a first surface facing the first interlayer insulating layer, a second surface facing the second interlayer insulating layer, and a third surface facing the first insulating layer,
• the first surface is connected to the third surface so that an interior angle between the first and third surfaces is less than 90 degree at a connecting portion of the first and third surfaces, and
• the second surface is connected to the third surface so that an interior angle between the second and third surfaces is less than 90 degree at a connecting portion of the second and third surfaces.