Semiconductor device and manufacturing method of a semiconductor device

1. A semiconductor device comprising:

a stack structure including conductive patterns spaced apart from each other;

a channel structure penetrating the stack structure;

a slit insulating layer penetrating the stack structure in a first direction; and

a source contact in contact with the slit insulating layer,

wherein air gaps are defined between the conductive patterns,

wherein the slit insulating layer includes a first interposition part covering a sidewall of one of the conductive patterns and a second interposition part covering one of the air gaps from the side,

wherein a smallest width of the second interposition part in a second direction perpendicular to the first direction is smaller than a smallest width of the first interposition part in the second direction,

wherein the source contact includes a first contact part covering the first interposition part of the slit insulating layer and a second contact part covering the second interposition part of the slit insulating layer, and

wherein an interface between the first contact part of the source contact and the first interposition part of the slit insulating layer is convex towards the first contact part of the source contact.

2. The semiconductor device of claim 1 ,

wherein a width of the second interposition part becomes larger as approaching the first interposition part from a central level of the second interposition part.

3. The semiconductor device of claim 1 ,

wherein a width of the first interposition part becomes smaller approaching the second interposition part from a central level of the first interposition part.

4. The semiconductor device of claim 1 ,

wherein a width of the second interposition part is smallest at a central level of an air gap adjacent to the second interposition part.

5. The semiconductor device of claim 1 ,

wherein a largest width of the second contact part is larger than a largest width of the first contact part.

6. The semiconductor device of claim 1 ,

wherein the second interposition part includes a second sidewall defining an air gap adjacent to the second interposition part and a first sidewall facing the second sidewall, and

wherein the first sidewall and the second sidewall are formed asymmetrically to each other.

7. The semiconductor device of claim 6 ,

wherein the first sidewall and the second sidewall are curved.

8. The semiconductor device of claim 1 , further comprising:

a memory layer surrounding the channel structure; and

protective patterns disposed between the memory layer and the respective conductive patterns.

9. The semiconductor device of claim 8 ,

wherein each of the protective patterns is in contact with a top surface, a sidewall, and a bottom surface of each of the conductive patterns, respectively.

10. The semiconductor device of claim 8 ,

wherein the protective patterns are disposed between the air gaps.

11. A semiconductor device comprising:

a stack structure including conductive patterns spaced apart from each other;

a channel structure penetrating the stack structure;

a slit insulting layer penetrating the stack structure in a first direction; and

a source contact in contact with the slit insulating layer,

wherein air gaps are defined between the conductive patterns,

wherein the slit insulating layer includes a first interposition part disposed between one of the conductive patterns and the source contact, and a second interposition part disposed between one of the air gaps and the source contact,

wherein the one of the conductive patterns abuts the one of the air gaps,

wherein the first interposition part includes a first sidewall in contact with the source contact and a second sidewall in contact with the one of the conductive patterns,

wherein the first sidewall is convex in a direction away from the one of the conductive patterns, and

wherein at least a portion of the one of the air gaps protrudes more than the second sidewall toward the source contact.

12. The semiconductor device of claim 11 ,

wherein the first and second sidewalls are formed symmetrically to each other.

13. The semiconductor device of claim 11 ,

wherein a sidewall of the source contact is curved to correspond to the first sidewall of the first interposition part of the slit insulating layer.

14. The semiconductor device of claim 11 ,

wherein the slit insulating layer includes a first insulating part in contact with at least one of the conductive patterns and a second insulating part covering a sidewall of the first insulating part.

15. The semiconductor device of claim 14 ,

wherein the first insulating part comprises a plurality of first insulating parts,

wherein the first insulating parts are spaced apart from each other, and

wherein the second insulating part is in contact with the first insulating parts.

16. The semiconductor device of claim 14 ,

wherein a largest width of the first insulating part is larger than a largest width of the second insulating part.