Nonvolatile semiconductor memory device and method for manufacturing same

A nonvolatile semiconductor memory device, comprising:

• a substrate;
• a stacked body provided on the substrate and including alternately stacked pluralities of isolation dielectric films and electrode films, a through-hole being formed in the stacked body to extend in the stacking direction;
• a semiconductor pillar buried in the through-hole;
• and
• a charge storage layer provided between the electrode films and the semiconductor pillar, the electrode film protruding further than the isolation dielectric film toward the semiconductor pillar at an inner face of the through-hole, a corner of the electrode film being rounded.

A nonvolatile semiconductor memory device, comprising:

• a substrate;
• a stacked body provided on the substrate and including alternately stacked pluralities of isolation dielectric films and electrode films, a through-hole being formed in the stacked body to extend in the stacking direction;
• a semiconductor pillar buried in the through-hole;
• and
• a charge storage layer provided between the electrode films and the semiconductor pillar,
• the electrode film protruding further than the isolation dielectric film toward the semiconductor pillar at an inner face of the through-hole, an end face of a portion of the isolation dielectric film contacting the electrode film being disposed at a position more distal than end faces of other portions of the isolation dielectric film as viewed from the semiconductor pillar.

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

• alternately stacking a plurality of isolation dielectric films and a plurality of electrode films on a substrate to form a stacked body;
• forming a through-hole in the stacked body to extend in the stacking direction;
• etching an inner face of the through-hole;
• forming a charge storage layer on the inner face of the through-hole;
• and
• burying a semiconductor pillar in the through-hole, the stacking of the isolation dielectric films including:
• forming a first high density film;
• forming a low density film on the first high density film, the low density film being less dense than the first high density film;
• and
• forming a second high density film on the low density film, the second high density film being denser than the low density film.

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

• alternately stacking a plurality of isolation dielectric films and a plurality of electrode films on a substrate to form a stacked body;
• forming a through-hole in the stacked body to extend in the stacking direction;
• etching an inner face of the through-hole;
• forming a charge storage layer on the inner face of the through-hole;
• and
• burying a semiconductor pillar in the through-hole,
• the stacking of the isolation dielectric films including:
• forming a first low density film;
• forming a high density film on the first low density film, the high density film being denser than the first low density film;
• and
• forming a second low density film on the high density film, the second low density film being less dense than the high density film.