Interconnections for 3D memory
View Patent ↗Apparatuses and methods for interconnections for 3D memory are provided. One example apparatus can include a stack of materials including a plurality of pairs of materials, each pair of materials including a conductive line formed over an insulation material. The stack of materials has a stair step structure formed at one edge extending in a first direction. Each stair step includes one of the pairs of materials. A first interconnection is coupled to the conductive line of a stair step, the first interconnection extending in a second direction substantially perpendicular to a first surface of the stair step.
1. An apparatus, comprising:
a stack of materials including a plurality of pairs of materials, pairs of materials including a conductive line formed over an insulation material, the stack of materials having a stair step structure formed at one edge extending in a first direction, a stair step including one of the pairs of materials;
a first interconnection coupled to the conductive line of a stair step, the first interconnection extending in a second direction substantially perpendicular to a first surface of the stair step; and
a second interconnection coupled to the first interconnection, the second interconnection extending in a third direction substantially perpendicular to both the first and second directions, wherein the second interconnection is substantially parallel to a bit line.
2. The apparatus of claim 1 , wherein the second interconnection does not extend beyond a rectangular area bounded on one side by the stack of materials and bounded on a second side by the stair step structure.
3. The apparatus of claim 1 , further comprising a third interconnection coupled to the second interconnection, the third interconnection extending in a direction opposite the second direction, the third interconnection being substantially parallel with the first interconnection.
4. The apparatus of claim 3 , wherein the third interconnection extends to an elevation below the stack of materials.
5. The apparatus of claim 3 , further comprising a fourth interconnection coupled to the third interconnection, the fourth interconnection extending in the first direction.
6. The apparatus of claim 3 , further comprising a fourth interconnection coupled to the third interconnection, the fourth interconnection extending in a direction opposite the first direction.
7. The apparatus of claim 3 , wherein the fourth interconnection extends underneath the stack of materials.
8. The apparatus of claim 1 , wherein the second interconnection is arranged such that a pitch of the second interconnection is independent of a width of the stack of materials in the second direction.
9. The apparatus of claim 1 , wherein the stack of materials has a first width in a direction perpendicular to the first direction, and the stair step structure has a second width in a direction perpendicular to the first direction, the second width being less than the first width.
10. The apparatus of claim 9 , wherein a stair step of the stair step structure extends in the first direction a length corresponding to the pitch of the second interconnection.
11. A method of forming a memory, comprising:
forming a stack of pairs of materials, the pairs of materials including a conductive line formed over an insulation material, the conductive line having a longest dimension in a first direction, the stack of pairs of materials having a wide width portion and a narrow width portion;
forming a stair step structure on one edge of the stack of pairs of materials;
forming an ascending interconnection coupled to the conductive line at a stair step, the ascending interconnection extending in a first direction substantially perpendicular to a first surface of the stair step structure;
forming a top planar interconnection coupled to the ascending interconnection, the top planar interconnection having a longest dimension in a direction different than the first direction and being substantially parallel to a bit line; and
forming a descending interconnection coupled to the top planar interconnection, the descending interconnection extending in a direction substantially parallel to the first direction.
12. The method of claim 11 , further comprising forming a bottom planar interconnection coupled to the descending interconnection, wherein the bottom planar interconnection has a longest dimension in the first direction.
13. The method of claim 12 , wherein a first bottom planar interconnection extends in a first radial direction from a descending interconnection, and a second bottom planar interconnection extends in a second radial direction from a descending interconnection, the second radial direction being different from the first radial direction.
14. The method of claim 12 , wherein the second radial direction is an opposite radial direction from the first radial direction.
15. The method of claim 12 , wherein the bottom planar interconnection has a longest dimension in the first direction.
16. The method of claim 11 , wherein forming the stack of pairs of materials includes removing a portion of the stack of pairs of materials in an area adjacent to the wide width portion and the narrow width portion.
17. The method of claim 16 , wherein removing the portion of the stack of pairs of materials occurs after forming the stair step structure, the area including a portion of the stair step structure.
18. The method of claim 16 , wherein the descending interconnections pass within the area.
19. A method of operating a memory, comprising:
performing a read operation or a program operation;
equalizing potential of access lines for a block of the memory after the read operation or the program operation is completed; and
setting potential of equalized access lines for the block of the memory to a reference potential,
wherein the memory is a three dimensional memory including:
a stack of access lines configured to have a stair step structure on an edge, the access lines being coupled to circuitry controlling the equalizing through a first interconnection formed of a same material as the access lines and having a longest dimension in a first direction substantially perpendicular to a direction of a longest dimension of the access lines; and
a second interconnection coupled to the first interconnection, the second interconnection extending in a second direction substantially perpendicular to the stack of access lines and the first direction, wherein the second interconnection is substantially parallel to a bit line.
20. The method of claim 19 , further comprising discharging the access lines to a ground reference potential after equalizing.
21. The method of claim 20 , further comprising biasing the access lines to potentials different than the reference potential after discharging.
22. The method of claim 21 , wherein biasing the access lines to potentials different than the reference potential includes biasing the access lines each to a different potential.
23. The method of claim 19 , wherein equalizing the access lines includes coupling all of the access lines together.
24. The method of claim 19 , further comprising biasing the access lines each to a different potential after equalizing.
25. The method of claim 19 , further comprising equalizing a plurality of select gate lines of the memory array to the same potential.
26. The method of claim 25 , wherein equalizing the plurality of select gate lines includes coupling the plurality of select gate lines to the access lines.