Memory devices

1. A memory device, comprising:

a multi-layer stack, disposed on a substrate and comprising a plurality of first conductive lines and a plurality of dielectric layers stacked alternately, wherein each of the plurality of first conductive lines has a first side and a second side opposite to the first side; and

a plurality of second conductive lines crossing over the plurality of first conductive lines, wherein widths of the plurality of second conductive lines are increased as the plurality of second conductive lines become far away from the first side.

2. The memory device of claim 1 further comprising a plurality of conductive contacts electrically connected to the first conductive lines, wherein the plurality of conductive contacts are disposed at the first side.

3. The memory device of claim 1 , wherein the plurality of second conductive lines are substantially perpendicular to the plurality of first conductive lines.

4. The memory device of claim 1 , wherein a plurality of spacings formed between the plurality of second conductive lines are decreased as the plurality of spacings become far away from the first side.

5. The memory device of claim 1 , wherein a plurality of spacings formed between the second conductive lines are substantially the same.

6. The memory device of claim 1 further comprising a plurality of dielectric pillars disposed on the substrate and penetrating through the multi-layer stack, wherein the plurality of dielectric pillars have a plurality of first conductive pillars and a plurality of second conductive pillars disposed at two ends thereof respectively, the plurality of first conductive pillars are electrically connected to first ones of the plurality of second conductive lines, and the plurality of second conductive pillars are electrically connected to second ones of the plurality of second conductive lines.

7. The memory device of claim 1 , wherein the plurality of first conductive lines comprise a plurality of word lines, and the plurality of the second conductive lines comprise a plurality of bit lines and a plurality of source lines.

8. A memory device, comprising:

a multi-layer stack, comprising a plurality of first conductive lines and a plurality of dielectric layers stacked alternately, the multi-layer stack comprising a memory region and a first staircase region and a second staircase region disposed on opposite sides of the memory region; and

a plurality of second conductive lines over the plurality of first conductive lines in the memory region, wherein widths of first portions of the plurality of second conductive lines are increased as the first portions of the plurality of second conductive lines become close to a middle of the memory region.

9. The memory device of claim 8 further comprising a plurality of conductive contacts electrically connected to the first conductive lines in the first staircase region.

10. The memory device of claim 8 further comprising a plurality of dielectric pillars penetrating through the multi-layer stack in the memory region, wherein the plurality of dielectric pillars have a plurality of first conductive pillars and a plurality of second conductive pillars disposed at two ends thereof respectively.

11. The memory device of claim 10 , wherein the plurality of second conductive lines electrically connected to the plurality of first conductive pillars are bit lines, and the plurality of second conductive lines electrically connected to the plurality of second conductive pillars are source lines.

12. The memory device of claim 8 , wherein the plurality of first conductive lines are respectively extended along a first direction, and the plurality of second conductive lines are respectively extended along a second direction substantially perpendicular to the first direction.

13. The memory device of claim 8 further comprising:

a channel layer in the memory region, penetrating through the plurality of first conductive layers and the plurality of dielectric layers; and

a memory material layer in the memory region, disposed between the channel layer and each of the plurality of first conductive layers and the plurality of dielectric layers.

14. The memory device of claim 8 , wherein widths of second portions of the plurality of second conductive lines are increased as the second portions of the plurality of second conductive lines become far away from the middle of the memory region.

15. The memory device of claim 14 , wherein the first portions and the second portions of the plurality of second conductive lines are disposed at opposite sides of the middle of the memory region.

16. A memory device, comprising:

a staircase structure, including a plurality of first conductive lines and a plurality of dielectric layers stacked alternately, the staircase structure comprising a memory region and a first staircase region aside the memory region; and

a plurality of second conductive lines over the plurality of first conductive lines in the memory region, wherein widths of the plurality of second conductive lines are increased as the plurality of second conductive lines become far away from the first staircase region.

17. The memory device of claim 16 further comprising a plurality of conductive contacts electrically connected to the first conductive lines, wherein the plurality of conductive contacts are disposed over the first staircase region.

18. The memory device of claim 16 further comprising a second staircase region, wherein the first staircase region and the second staircase region are disposed at opposite sides of the memory region.

19. The memory device of claim 16 , wherein the nearest one of the plurality of second conductive lines to the first staircase region has a first width, the farthest one of the plurality of second conductive lines to the first staircase region has a second width, and a ratio of the second width to the first width is in a range of about 5 to about 20.

20. The memory device of claim 16 , wherein a plurality of spacings formed between the plurality of second conductive lines are decreased as the plurality of spacings become far away from the first staircase region.