Nonvolatile memory device and method for fabricating the same
A three-dimensional nonvolatile memory device and a method for fabricating the same include a semiconductor substrate, a plurality of active pillars, a plurality of gate electrodes, and a plurality of supporters. The semiconductor substrate includes a memory cell region and a contact region. The active pillars extend in the memory cell region perpendicularly to the semiconductor substrate. The gate electrodes intersect the active pillars, extend from the memory cell region to the contact region and are stacked on the semiconductor substrate. The supporters extend in the contact region perpendicularly to the semiconductor substrate to penetrate at least one or more of the gate electrodes.
1. A nonvolatile memory device comprising:
a substrate including a first region and a second region;
an electrode structure including a plurality of electrodes vertically stacked on the substrate, the electrode structure having a stair step structure on the second region,
a plurality of first vertical layers penetrating the electrode structure on the first region;
a plurality of contact plugs on the second region and connected to respective ones of the plurality of electrodes;
at least one second vertical layer penetrating the electrode structure between the first region and the second region;
a plurality of bit lines crossing the electrode structure in the first region and connected to the plurality of first vertical layers; and
a plurality of conductive lines connected to the plurality of contact plugs,
wherein the at least one second vertical layer is free of connection with any bit line, and
wherein respective top surfaces of the plurality of conductive lines are coplanar with respective top surfaces of the plurality of bit lines.
2. The nonvolatile memory device of claim 1 , wherein the at least one second vertical layer is between a first group comprising the plurality of first vertical layers and a second group comprising the plurality of contact plugs, in a cross-sectional view.
3. The nonvolatile memory device of claim 1 , wherein the at least one second vertical layer is closer to the plurality of first vertical layers than to the plurality of contact plugs.
4. The nonvolatile memory device of claim 1 , wherein the at least one second vertical layer comprises a dielectric supporter and is spaced apart from the stair step structure.
5. The nonvolatile memory device of claim 1 , wherein the at least one second vertical layer and the plurality of first vertical layers each comprise an equal length in a vertical direction.
6. The nonvolatile memory device of claim 1 , wherein respective uppermost surfaces of the plurality of first vertical layers are coplanar with an uppermost surface of the at least one second vertical layer.
7. The nonvolatile memory device of claim 1 , wherein the plurality of first vertical layers and the at least one second vertical layer comprise semiconductor material.
8. The nonvolatile memory device of claim 1 ,
wherein respective top surfaces of the plurality of contact plugs are equidistant from a top surface of the substrate, and
wherein respective bottom surfaces of the plurality of contact plugs are located at different distances from the top surface of the substrate.
9. The nonvolatile memory device of claim 1 , wherein the plurality of contact plugs have a vertical length that increases with increasing distance from the first region.
10. A nonvolatile memory device comprising:
a substrate including a first region and a second region;
an electrode structure including a plurality of electrodes vertically stacked on the substrate, the electrode structure including a flat portion on the first region and a stair step portion on the second region;
a plurality of first vertical layers penetrating the flat portion of the electrode structure, in a cross-sectional view;
at least one second vertical layer penetrating an end region of the flat portion of the electrode structure, in the cross-sectional view;
a plurality of dielectric third vertical layers penetrating the stair step portion of the electrode structure, in the cross-sectional view;
a plurality of contact plugs on the stair step portion of the electrode structure and connected to respective ones of the plurality of electrodes;
a plurality of bit lines crossing the electrode structure in the first region and connected to the plurality of first vertical layers, respectively, in the cross-sectional view; and
a plurality of conductive lines in the second region and connected to the plurality of contact plugs,
wherein the at least one second vertical layer is spaced apart from the stair step portion of the electrode structure.
11. The nonvolatile memory device of claim 10 ,
wherein the electrode structure extends from the first region to the second region in a horizontal direction, and
wherein the end region of the flat portion of the electrode structure is between the stair step portion of the electrode structure and the plurality of first vertical layers.
12. The nonvolatile memory device of claim 10 , wherein the at least one second vertical layer and the plurality of first vertical layers each comprise an equal vertical length.
13. The nonvolatile memory device of claim 10 , wherein the plurality of first vertical layers and the at least one second vertical layer comprise semiconductor material.
14. The nonvolatile memory device of claim 10 ,
wherein an uppermost surface of the flat portion of the electrode structure has a uniform vertical height from the substrate,
wherein the stair step portion of the electrode structure has a vertical height that decreases with increasing distance from the first region,
wherein the plurality of electrodes comprise respective sidewalls located at different horizontal positions from each other, on the second region, and
wherein the plurality of contact plugs contact top surfaces of the respective ones of the plurality of electrodes.
15. The nonvolatile memory device of claim 12 , wherein the at least one second vertical layer is free of connection with any bit line.
16. A nonvolatile memory device comprising:
a substrate including a memory cell region and a contact region;
an electrode structure including a plurality of electrodes vertically stacked on the substrate;
a plurality of first vertical layers penetrating the electrode structure on the memory cell region;
at least one second vertical layer penetrating the electrode structure on the contact region,
wherein the at least one second vertical layer and the plurality of first vertical layers each comprise an equal length in a vertical direction;
a plurality of contact plugs on the contact region and connected to respective ones of the plurality of electrodes;
a plurality of bit lines crossing the electrode structure in the memory cell region and connected to the plurality of first vertical layers; and
a plurality of conductive lines connected to the plurality of contact plugs,
wherein the at least one second vertical layer is free of connection with any bit line.
17. The nonvolatile memory device of claim 16 ,
wherein the electrode structure has a stair step structure on the contact region, and
wherein the at least one second vertical layer is spaced apart from the stair step structure.
18. The nonvolatile memory device of claim 16 , wherein the plurality of first vertical layers and the at least one second vertical layer comprise semiconductor material.
19. The nonvolatile memory device of claim 16 ,
wherein respective top surfaces of the plurality of contact plugs are equidistant from a top surface of the substrate, and
wherein respective bottom surfaces of the plurality of contact plugs are located at different distances from the top surface of the substrate.