Layout of driver sets in a cross point memory array
View Patent ↗Layouts of driver sets in a cross point memory array. Since both terminals of a memory cell in a cross point structure are typically used for selection purposes, dedicated driver sets are typically required for both x and y directions. By fabricating the cross point array above the driver circuitry, several different driver set layouts can be utilized that allow for varying designs.
1. A re-writable memory comprising:
a semiconductor substrate;
a cross point memory array formed above the semiconductor substrate, including
at least one x-direction conductive layer that includes conductive array lines;
at least one y-direction conductive layer that includes conductive array lines; and
memory plugs;
at least one x-direction driver set that drives the at least one x-direction conductive layer, the at least one x-direction driver set being formed on the semiconductor substrate; and
at least one y-direction driver set that drives the at least one y-direction conductive layer, the at least one y-direction driver set being formed on the semiconductor substrate;
wherein the at least one x-direction driver set and the at least one y-direction driver set both use logic to drive isolated conductive array lines, and wherein at least one driver set is substantially underneath the cross point memory array.
2. The re-writable memory of claim 1 , wherein:
a first portion of at least one driver set is positioned on a first side of the cross point array, and a second portion of the at least one driver set is positioned on the opposite side of the cross point array.
3. The re-writable memory of claim 2 , wherein:
the first and second portions of the at least one driver set are interdigitated.
4. The re-writable memory of claim 3 , wherein:
the at least one driver set substantially underneath the cross point array is the at least one x-direction driver set.
5. The re-writable memory of claim 4 , wherein
the at least one y-direction driver set is not underneath the cross point memory array.
6. The re-writable memory of claim 4 , wherein:
a portion of the at least one y-direction driver set is underneath the cross point memory array.
7. The re-writable memory of claim 3 , wherein:
the at least one driver set substantially underneath the cross point array is the at least one y-direction driver set.
8. The re-writable memory of claim 7 , wherein
the at least one x-direction driver set is not underneath the cross point memory array.
9. The re-writable memory of claim 2 , wherein:
a portion of the at least one x-direction driver set is underneath the cross point memory array.
10. The re-writable memory of claim 2 , wherein:
the first and second portions of the at least one driver set are not interdigitated.
11. The re-writable memory of claim 10 , wherein:
all the driver sets are substantially underneath the cross point memory array.
12. The re-writable memory of claim 11 , wherein:
there are at least four driver sets that drive three x-direction conductive layers and two y-direction conductive layers.
13. The re-writable memory of claim 12 , wherein:
there are at least six driver sets that drive five x-direction conductive layers and four y-direction conductive layers.
14. The re-writable memory of claim 11 , further comprising:
other peripheral circuitry that is formed in the semiconductor substrate and is substantially underneath the cross point memory array.
15. A re-writable memory comprising:
a semiconductor substrate;
a cross point array that is formed on top of the semiconductor substrate and electrically connected to the semiconductor substrate, the cross point array including a layer of x-direction conductive array lines, a layer of memory plugs, and a layer of y-direction conductive array lines;
an x-direction driver set formed on the semiconductor substrate, each driver within the set being electrically coupled to a single x-direction conductive array line on the layer of x-direction conductive array lines; and
a y-direction driver set formed on the semiconductor substrate, each driver within the set being operably connected to a single y-direction conductive array line on the layer of y-direction conductive array lines and being operable to drive a memory plug to a read voltage or a write voltage in conjunction with the x-direction driver set;
wherein at least one of the driver sets is substantially underneath the cross point memory array.
16. The re-writable memory of claim 15 , wherein:
a first portion of at least one driver set is positioned on a first side of the cross point array, and a second portion of the at least one driver set is positioned on the opposite side of the cross point array.
17. The re-writable memory of claim 16 , wherein:
the first and second portions of the at least one driver set are interdigitated.
18. The re-writable memory of claim 16 , wherein:
the first and second portions of the at least one driver set are not interdigitated.
19. The re-writable memory of claim 15 , wherein:
all the driver sets are substantially underneath the cross point memory array.
20. The re-writable memory of claim 19 , wherein:
the cross point array has multiple layers of memory plugs.
21. A re-writable memory comprising:
a semiconductor substrate;
a cross point memory array formed above the semiconductor substrate, including
at least one x-direction conductive layer that includes conductive array lines;
at least one y-direction conductive layer that includes conductive array lines; and
memory plugs;
at least one x-direction driver set that drives the at least one x-direction conductive layer, the at least one x-direction driver set being formed on the semiconductor substrate; and
at least one y-direction driver set that drives the at least one y-direction conductive layer, the at least one y-direction driver set being formed on the semiconductor substrate;
wherein at least one x-direction driver set is entirely driving conductive array lines from one side of the conductive array.
22. The re-writable memory of claim 21 , wherein:
the at least one x-direction driver set and the at least one y-direction driver set both use logic to drive isolated conductive array lines.
23. The re-writable memory of claim 21 , wherein:
the at least one x-direction driver set is substantially underneath the cross point memory array.
24. The re-writable memory of claim 23 , wherein:
all x-direction driver sets are substantially underneath the cross point memory array.
25. The re-writable memory of claim 21 , wherein:
the memory plugs exhibit a non-linear resistive characteristic.
26. The re-writable memory of claim 25 , wherein:
the memory plug includes a conductive metal oxide.
27. A re-writable memory comprising:
a semiconductor substrate;
a cross point memory array formed above the semiconductor substrate, including
at least one x-direction conductive layer that includes a portion of contiguous x-direction conductive array lines;
at least one y-direction conductive layer that includes a portion of contiguous y-direction conductive array lines; and
memory plugs;
at least one x-direction driver set that drives the at least one x-direction conductive layer, the at least one x-direction driver set including a non-interdigitated driver subset that
drives the portion of contiguous x-direction conductive array lines; and
is formed on the semiconductor substrate such that it makes electrical contact with the portion of contiguous x-direction conductive array lines from a first side of the cross point array; and at least one y-direction driver set that drives the at least one y-direction conductive layer, the at least one y-direction driver set being formed on the semiconductor substrate.
28. The re-writable memory of claim 27 , wherein:
the non-interdigitated driver subset is placed underneath the cross point memory array.
29. The re-writable memory of claim 27 , wherein:
the at least one x-direction conductive layer includes a second portion of contiguous x-direction conductive array lines; and
the at least one x-direction driver set includes a second non-interdigitated driver subset that
drives the second portion of contiguous x-direction conductive array lines; and
is formed on the semiconductor substrate such that it makes electrical contact with the second portion of contiguous x-direction conductive array lines from a second side of the cross point array, the second side being opposite from the first side.
30. The re-writable memory of claim 29 , wherein:
the at least one y-direction driver set includes a second non-interdigitated driver subset that
drives the portion of contiguous y-direction conductive array lines; and
is formed on the semiconductor substrate such that it makes electrical contact with the portion of contiguous y-direction conductive array lines from a third side of the cross point array, the third side being adjacent to the first side.
31. The re-writable memory of claim 30 , wherein:
the at least one y-direction conductive layer includes a second portion of contiguous y-direction conductive array lines; and
the at least one y-direction driver set includes a second non-interdigitated driver subset that
drives the second portion of contiguous y-direction conductive array lines; and
is formed on the semiconductor substrate such that it makes electrical contact with the second portion of contiguous y-direction conductive array lines from a fourth side of the cross point array, the fourth side being opposite from the third side.
32. The re-writable memory of claim 31 , wherein:
the x-driver subsets and the y-driver subsets are placed underneath the cross point memory array.
33. The re-writable memory of claim 27 , wherein:
the cross point memory array formed above the semiconductor substrate is one of a plurality of cross point memory arrays formed above the semiconductor substrate.
34. The re-writable memory of claim 33 , wherein:
the memory is organized to read or write N bits of data at a time, and
the number of cross point memory arrays in the plurality of cross point memory arrays is N or a multiple of N.
35. The re-writable memory of claim 27 , wherein:
the re-writable memory is a portable storage device.
36. The re-writable memory of claim 35 , wherein:
the memory plugs exhibit a non-linear resistive characteristic.
37. The re-writable memory of claim 36 , wherein:
the memory plug includes a conductive metal oxide.