Nonvolatile semiconductor memory device and method of manufacturing the same

A method of manufacturing a nonvolatile semiconductor memory device, comprising:

• alternately stacking a plurality of conductive layers and an inter-layer insulating layer in a first direction;
• forming a memory hole that penetrates the plurality of conductive layers and the inter-layer insulating layer;
• sequentially forming a charge accumulation layer, a tunnel insulating layer, and a semiconductor layer in the memory hole;
• forming a first trench that divides the plurality of conductive layers and the inter-layer insulating layer;
• and
• rounding an end exposed in the first trench of the plurality of conductive layers.

A method of manufacturing a nonvolatile semiconductor memory device, comprising:

• alternately stacking a plurality of inter-layer insulating layers and a plurality of first sacrifice layers in a first direction;
• forming a memory hole that penetrates the plurality of inter-layer insulating layers and the plurality of first sacrifice layers;
• sequentially forming a charge accumulation layer, a tunnel insulating layer, and a semiconductor layer in the memory hole;
• forming a first trench that divides the plurality of inter-layer insulating layers and the plurality of first sacrifice layers;
• removing the first sacrifice layer via the first trench;
• forming a conductive layer between the plurality of inter-layer insulating layers;
• and
• rounding an end exposed in the first trench of the plurality of conductive layers.