Three-dimensional semiconductor memory device

1. A three-dimensional semiconductor memory device, comprising:

a peripheral circuit structure including:

peripheral circuits on a semiconductor substrate,

landing pads connected to the peripheral circuits, and

a lower dielectric layer that covers the peripheral circuits and the landing pads;

an electrode structure on the peripheral circuit structure, the electrode structure including vertically stacked electrodes;

a planarized dielectric layer that covers the electrode structure;

peripheral through plugs spaced apart from the electrode structure, the peripheral through plugs penetrating the planarized dielectric layer to connect to the landing pads;

conductive lines connected through contact plugs, respectively, to the peripheral through plugs; and

at least one dummy through plug adjacent to a first peripheral through plug of the peripheral through plugs, the at least one dummy through plug penetrating the planarized dielectric layer and extending into the lower dielectric layer, and the at least one dummy through plug being in direct contact with the lower dielectric layer and insulated from the conductive lines.

2. The device as claimed in claim 1 , wherein the peripheral through plugs include:

a second peripheral through plug spaced apart at a first distance from the first peripheral through plug; and

a third peripheral through plug spaced apart at a second distance from the second peripheral through plug, the second distance being less than the first distance.

3. The device as claimed in claim 1 , wherein each of the peripheral through plugs has a first upper width, and the at least one dummy through plug has a second upper width less than the first upper width.

4. The device as claimed in claim 3 , wherein a bottom surface of the at least one dummy through plug is at a level higher than a level of a bottom surface of the first peripheral through plug.

5. The device as claimed in claim 1 , wherein each of the peripheral through plugs has a first upper width, and the at least one dummy through plug has a second upper width that substantially equals the first upper width.

6. The device as claimed in claim 5 , wherein the at least one dummy through plug is coupled to one of the landing pads.

7. The device as claimed in claim 1 , wherein a bottom surface of the at least one dummy through plug is at a level different from a level of a bottom surface of the first peripheral through plug.

8. The device as claimed in claim 1 , wherein:

a top surface of the at least one dummy through plug is at a same level as a level of a top surface of the first peripheral through plug, and

when viewed in a direction perpendicular to a top surface of the semiconductor substrate, a length of the at least one dummy through plug is different from a length of the first peripheral through plug.

9. The device as claimed in claim 1 , wherein the at least one dummy through plug does not overlap the peripheral circuits.

10. The device as claimed in claim 1 , wherein the at least one dummy through plug includes at least two dummy through plugs surrounding the first peripheral through plug.

11. The device as claimed in claim 1 , further comprising:

a horizontal layer between the peripheral circuit structure and the electrode structure, the horizontal layer including a cell array region, a first connection region, and a second connection region; and

cell through plugs on the first connection region, the cell through plugs penetrating the electrode structure to connect to the peripheral circuit structure,

wherein the electrode structure has a stepwise structure on the first connection region.

12. The device as claimed in claim 11 , wherein the electrode structure further includes mold patterns on the first connection region, the mold patterns being at same levels as levels of the electrodes, and the cell through plugs penetrating the mold patterns.

13. A three-dimensional semiconductor memory device, comprising:

a peripheral circuit structure including:

peripheral circuits on a semiconductor substrate, and

landing pads connected to the peripheral circuits;

a horizontal layer on the peripheral circuit structure, the horizontal layer including a cell array region, a first connection region, and a second connection region;

an electrode structure on the cell array region and the first connection region, the electrode structure including electrodes vertically stacked with a stepwise structure on the first connection region;

a planarized dielectric layer covering the electrode structure;

peripheral through plugs on the second connection region, the peripheral through plugs penetrating the planarized dielectric layer to connect to the landing pads, and the peripheral though plugs including:

a first peripheral through plug,

a second peripheral through plug spaced apart at a first distance from the first peripheral through plug,

a third peripheral through plug spaced apart at a second distance from the second peripheral through plug, the second distance being less than the first distance, and

at least one dummy through plug adjacent to the first peripheral through plug, the at least one dummy through plug penetrating the planarized dielectric layer,

wherein each of the first, second, and third peripheral through plugs has a first upper width,

wherein the at least one dummy through plug has a second upper width less than the first upper width, and

wherein a bottom surface of the at least one dummy through plug is in direct contact with a dielectric layer that covers the peripheral circuits and the landing pads.

14. The device as claimed in claim 13 , further comprising:

an interlayer dielectric layer on the planarized dielectric layer; and

conductive lines on the interlayer dielectric layer, the conductive lines being correspondingly connected through contact plugs to the first, second, and third peripheral through plugs,

wherein the at least one dummy through plug is insulated from the conductive lines.

15. The device as claimed in claim 13 , wherein a bottom surface of the at least one dummy through plug is at a level different from a level of a bottom surface of the first peripheral through plug.

16. The device as claimed in claim 13 , wherein:

a top surface of the at least one dummy through plug is at a same level as a level of a top surface of the first peripheral through plug, and

when viewed in a direction perpendicular to a top surface of the semiconductor substrate, a length of the at least one dummy through plug is different from a length of the first peripheral through plug.

17. A three-dimensional semiconductor memory device, comprising:

a peripheral circuit structure including:

peripheral circuits on a semiconductor substrate,

landing pads connected to the peripheral circuits, and

a dielectric layer that covers the peripheral circuits and the landing pads;

a horizontal layer on the dielectric layer of the peripheral circuit structure, the horizontal layer including a cell array region, a first connection region, and a second connection region;

an electrode structure on the cell array region and the first connection region, the electrode structure including electrodes vertically stacked with a stepwise structure on the first connection region;

a planarized dielectric layer covering the electrode structure;

vertical channel structures on the cell array region, the vertical channel structures penetrating the electrode structure;

a cell through plug on the first connection region and coupled to a first landing pad of the landing pads, the cell through plug penetrating the electrode structure;

a first peripheral through plug on the second connection region and coupled to a second landing pad of the landing pads;

a second peripheral through plug spaced apart at a first distance from the first peripheral through plug;

a third peripheral through plug spaced apart at a second distance from the second peripheral through plug, the second distance being less than the first distance;

at least one dummy through plug adjacent to the first peripheral through plug, the at least one dummy through plug penetrating the planarized dielectric layer, and a bottom surface of the at least one dummy through plug being in direct contact with the dielectric layer of the peripheral circuit structure;

an interlayer dielectric layer on the planarized dielectric layer; and

conductive lines on the interlayer dielectric layer, the conductive lines being correspondingly connected through contact plugs to the first, second, and third peripheral through plugs,

wherein each of the first, second, and third peripheral through plugs has a first upper width, and

wherein the dummy through plug has a second upper width less than the first upper width.

18. The device as claimed in claim 17 , wherein:

a top surface of the at least one dummy through plug is at a same level as a level of top surfaces of the first, second, and third peripheral through plugs, and

when viewed in a direction perpendicular to a top surface of the semiconductor substrate, a length of the at least one dummy through plug is different from a length of the first peripheral through plug.