Semiconductor device and manufacturing method thereof

1. A semiconductor device comprising:

a first source seed layer;

a second source seed layer disposed over the first source seed layer while being spaced apart from the first source seed layer;

a stacked structure formed on the second source seed layer;

channel layers extending inside the first source seed layer by penetrating the stacked structure; and

an interlayer source layer extending into a space between the first source seed layer and the second source seed layer while directly contacting the channel layers, the first source seed layer, and the second source seed layer.

2. The semiconductor device of claim 1 , wherein the first source seed layer, the second source seed layer, and the interlayer source layer include an n-type or p-type dopant.

3. The semiconductor device of claim 1 , wherein the first source seed layer, the second source seed layer, and the interlayer source layer include silicon.

4. The semiconductor device of claim 1 , further comprising an etch stop source layer formed on the second source seed layer, the etch stop source layer being formed of a material having a higher etching selection ratio with respect to an oxide layer than the second source seed layer.

5. The semiconductor device of claim 4 , wherein the etch stop source layer includes carbon doped polysilicon.

6. The semiconductor device of claim 1 , wherein the stacked structure includes interlayer dielectric layers and conductive patterns, which are alternately stacked.

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

a slit penetrating the stacked structure and the second source seed layer between the channel layers;

a sidewall insulating layer formed on a sidewall of the slit; and

a slit insulating layer filling in the slit, the slit insulating layer being formed on the sidewall insulating layer, the slit insulating layer extending to an upper portion of the interlayer source layer.

8. The semiconductor device of claim 7 , wherein the sidewall insulating layer is formed as a single layer of a nitride layer.

9. The semiconductor device of claim 7 , wherein the sidewall insulating layer includes:

a first sidewall insulating layer including a nitride layer;

a second sidewall insulating layer surrounded by the first sidewall insulating layer, the second sidewall insulating layer including an oxide layer; and

a third sidewall insulating layer surrounded by the second sidewall insulating layer, the third sidewall insulating layer including a nitride layer.

10. The semiconductor device of claim 1 , comprising:

a first multi-layered pattern surrounding the outer wall of a first portion of each of the channel layers, which penetrates the stacked structure and the second source seed layer; and

a second multi-layered pattern surrounding the outer wall of a second portion of each of the channel layers, which penetrates an upper portion of the first source seed layer.

11. The semiconductor device of claim 10 , wherein the first multi-layered pattern and the second multi-layered pattern are separated by the interlayer source layer.

12. The semiconductor device of claim 10 , wherein each of the first multi-layered pattern and the second multi-layered pattern includes:

a tunnel insulating layer surrounding the outer wall of each of the channel layers;

a data storage layer surrounding the tunnel insulating layer; and

a blocking insulating layer surrounding the data storage layer.

13. The semiconductor device of claim 1 , further comprising a metal source layer disposed under the first source seed layer, the metal source layer being formed of a material having a lower resistance than the first source seed layer and the second source seed layer.

14. The semiconductor device of claim 13 , further comprising:

a first barrier metal layer surrounding the sidewall and bottom surface of the metal source layer; and

a second barrier metal layer disposed between the first source seed layer and the metal source layer.

15. The semiconductor device of claim 1 , wherein the interlayer source layer surrounds a portion of each of the channel layers, the portion disposed between the first source seed layer and the second source seed layer.