Manufacturing method of semiconductor device

A method of manufacturing a semiconductor device, the method comprising:

• forming a sacrificial structure that includes first, second, third, and fourth sacrificial layers;
• forming a stacked structure over the sacrificial structure, the stacked structure including first material layers and second material layers that are alternately stacked;
• forming a channel layer that passes through the stacked structure, and the sacrificial structure, the channel layer being enclosed by a memory layer;
• forming a slit that passes through the stacked structure and the fourth sacrificial layer, the slit exposing the third sacrificial layer;
• forming a polysilicon spacer in the slit;
• exposing the second sacrificial layer by etching the third sacrificial layer through the slit;
• forming an opening that exposes the memory layer by removing the second and third sacrificial layers through the slit;
• removing a part of the memory layer, the first sacrificial layer, and the fourth sacrificial layer to expose the channel layer;
• and
• forming a source layer that contacts the channel layer in the opening.

A method of manufacturing a semiconductor device, the method comprising:

• sequentially forming first, second, third, and fourth sacrificial layers over a first source layer to form a sacrificial structure;
• forming a second source layer over the sacrificial structure;
• forming a stacked structure over the second source layer, the stacked structure including first material layers and second material layers that are alternately stacked;
• forming a channel layer that passes through the stacked structure, the second source layer, and the sacrificial structure, and forming a memory layer that encloses the channel layer;
• forming a slit that passes through the stacked structure, the second source layer, and the fourth sacrificial layer and exposes the third sacrificial layer;
• forming a polysilicon spacer in the slit;
• exposing the first source layer by etching the first, second, and third sacrificial layers using the polysilicon spacer as a protective layer;
• forming an opening that exposes the memory layer by removing the second and third sacrificial layers using the polysilicon spacer as the protective layer;
• removing a part of the memory layer, the first sacrificial layer, and the fourth sacrificial layer to expose the channel layer;
• and
• forming a third source layer that contacts the channel layer in the opening.