Three-dimensional semiconductor memory devices

1. A three-dimensional (3D) semiconductor memory device comprising:

a source structure on a horizontal semiconductor layer, the source structure comprising a first source conductive pattern and a second source conductive pattern which are sequentially stacked on the horizontal semiconductor layer;

an electrode structure comprising a plurality of electrodes vertically stacked on the source structure;

a vertical semiconductor pattern penetrating the electrode structure and the source structure;

a contact plug penetrating the electrode structure and the source structure and spaced apart from the vertical semiconductor pattern; and

an insulating spacer disposed between the contact plug and the electrode structure,

wherein the contact plug comprises a lower portion adjacent to the source structure, and

wherein the lower portion of the contact plug includes a void.

2. The 3D semiconductor memory device of claim 1 ,

wherein the void of the lower portion of the contact plug is positioned at a level between a top surface of the first source conductive pattern and a bottom surface of the first source conductive pattern.

3. The 3D semiconductor memory device of claim 1 ,

wherein the contact plug further comprises an upper portion adjacent to the electrode structure, and

wherein a width of the lower portion is greater than a width of the upper portion.

4. The 3D semiconductor memory device of claim 1 ,

wherein a portion of a sidewall of the vertical semiconductor pattern is in contact with the source structure.

5. The 3D semiconductor memory device of claim 1 ,

wherein the first source conductive pattern includes a discontinuous interface at a level between a top surface of the horizontal semiconductor layer and a bottom surface of the second source conductive pattern.

6. The 3D semiconductor memory device of claim 5 ,

wherein the discontinuous interface is laterally spaced apart from the vertical semiconductor pattern and the contact plug.

7. The 3D semiconductor memory device of claim 5 ,

wherein the discontinuous interface is enclosed by the first source conductive pattern.

8. The 3D semiconductor memory device of claim 1 ,

wherein the contact plug further comprises an upper portion adjacent to the electrode structure, and

wherein the upper portion of the contact plug includes a discontinuous interface.

9. The 3D semiconductor memory device of claim 1 ,

wherein a first portion of a sidewall of the vertical semiconductor pattern is horizontally spaced apart from the second source conductive pattern, and

wherein a second portion of the sidewall of the vertical semiconductor pattern is in contact with the first source conductive pattern.

10. The 3D semiconductor memory device of claim 1 ,

wherein the first and second source conductive patterns include a semiconductor material doped with charge carrier impurities having a first conductivity type, and

wherein a concentration of the charge carrier impurities in the first source conductive pattern is greater than a concentration of the charge carrier impurities in the second source conductive pattern.

11. The 3D semiconductor memory device of claim 1 , further comprising:

a data storage pattern vertically extending between the vertical semiconductor pattern and the electrode structure,

wherein a bottom surface of the data storage pattern is in contact with a portion of the first source conductive pattern.

12. The 3D semiconductor memory device of claim 11 ,

wherein the bottom surface of the data storage pattern is located at a level between a bottom surface of a lowermost one of the electrodes and a bottom surface of the second source conductive pattern.

13. The 3D semiconductor memory device of claim 1 ,

wherein the first source conductive pattern comprises:

a lower portion adjacent to a top surface of the horizontal semiconductor layer; and

an upper portion adjacent to a bottom surface of the second source conductive pattern, and

wherein the upper portion of the first source conductive pattern and the lower portion of the first source conductive pattern have different crystal structures from each other.

14. The 3D semiconductor memory device of claim 13 ,

wherein the first source conductive pattern further comprises:

a sidewall portion which extends from the upper and lower portions of the first source conductive pattern in a direction perpendicular to the top surface of the horizontal semiconductor layer and surrounds a second portion of a sidewall of the vertical semiconductor pattern.

15. The 3D semiconductor memory device of claim 14 ,

wherein a top surface of the sidewall portion of the first source conductive pattern is located at a level between a bottom surface of a lowermost one of the electrodes and a top surface of the first source conductive pattern, and

wherein a bottom surface of the sidewall portion of the first source conductive pattern is located at a level between a bottom surface of the vertical semiconductor pattern and the top surface of the horizontal semiconductor layer.

16. The 3D semiconductor memory device of claim 13 ,

wherein the upper portion of the first source conductive pattern includes amorphous or poly-crystalline silicon, and

wherein the lower portion of the first source conductive pattern includes single-crystalline silicon.

17. The 3D semiconductor memory device of claim 13 ,

wherein the upper portion of the first source conductive pattern includes amorphous silicon, and

wherein the lower portion of the first source conductive pattern includes poly-crystalline silicon.

18. A three-dimensional (3D) semiconductor memory device comprising:

peripheral circuits integrated on a semiconductor substrate;

peripheral interconnection lines connected to the peripheral circuits;

a lower insulating layer covering the peripheral circuits and the peripheral interconnection lines;

a horizontal semiconductor layer on the lower insulating layer;

a source structure on the horizontal semiconductor layer, the source structure comprising a first source conductive pattern and a second source conductive pattern which are sequentially stacked on the horizontal semiconductor layer;

an electrode structure comprising a plurality of electrodes vertically stacked on the source structure;

a vertical semiconductor pattern penetrating the electrode structure and the source structure;

a data storage pattern vertically extending between the vertical semiconductor pattern and the electrode structure;

a contact plug penetrating the electrode structure and the source structure and spaced apart from the vertical semiconductor pattern; and

an insulating spacer disposed between the contact plug and the electrode structure,

wherein a portion of a sidewall of the vertical semiconductor pattern is in contact with the first source conductive pattern, and

wherein the contact plug comprises a lower portion adjacent to the source structure, and

wherein the lower portion of the contact plug includes a void.

19. The 3D semiconductor memory device of claim 18 ,

wherein the void of the lower portion of the contact plug is positioned at a level between a top surface of the first source conductive pattern and a bottom surface of the first source conductive pattern.

20. The 3D semiconductor memory device of claim 18 , wherein the first source conductive pattern includes a discontinuous interface at a level between a top surface of the horizontal semiconductor layer and a bottom surface of the second source conductive pattern.