Three-dimensional type nand memory device

A method of manufacturing a semiconductor device, comprising:

• forming a stacked film alternately including a plurality of first layers and a plurality of second layers in a first direction;
• forming a hole extending in the first direction in the stacked film;
• forming a first insulator on a side face of the stacked film in the hole;
• removing the first insulator in the hole to expose a first part of the side face of the stacked film at a predetermined height in the first direction of the hole and to expose a side face of the first insulator remaining on a second part of the side face of the stacked film at the predetermined height;
• forming a second insulator on the first part of the side face of the stacked film and the side face of the remaining first insulator in the hole;
• forming a charge storage layer on a side face of the second insulator in the hole;
• forming a third insulator on a side face of the charge storage layer in the hole;
• and
• forming a semiconductor layer on a side face of the third insulator in the hole.