Semiconductor device and manufacturing method of the semiconductor device

A semiconductor device, comprising:

• a stacked structure including insulating layers and conductive layers alternately stacked on each other;
• a hard mask pattern located on the stacked structure;
• a channel structure passing through the hard mask pattern and the stacked structure;
• insulating patterns interposed between the insulating layers and the channel structure, wherein each insulating pattern includes a first surface and a second surface, wherein the first surface faces each of the insulating layers and is flat, and wherein the second surface faces the channel structure and includes a curved surface;
• and
• a memory layer interposed between the stacked structure and the channel structure, wherein the memory layer fills a space between the insulating patterns,
• wherein a sidewall of each of the conductive layers is located on an extending line of a sidewall of the hard mask pattern, and wherein the insulating patterns protrude farther towards the channel structure than the sidewall of the hard mask pattern.