Self-aligned cross-point phase change memory-switch array
View Patent ↗Subject matter disclosed herein relates to a memory device, and more particularly to a self-aligned cross-point phase change memory-switch array and methods of fabricating same.
1. A method of forming a cross-point memory array, comprising:
forming a set of substantially parallel rows of a first multiple-layer memory structure separated by first trenches, the first multi-layer memory structure comprising a first phase change material layer between a first memory electrode layer and a second memory electrode layer;
filling said first trenches with a first passivation material to form a first resulting structure; and
forming a set of substantially parallel columns of a second multiple-layer switch structure perpendicular to said parallel rows over said first resulting structure, the second multi-layer switch structure having a switch layer comprising a second phase change material layer,
wherein forming the set of substantially parallel columns of the second multi-layer switch structure comprises etching the first phase change material layer, the first memory electrode layer and the second memory electrode layer.
2. The method of claim 1 , wherein said first multiple-layer memory structure further comprises a row metal layer covered with the first phase change material layer between the first memory electrode layer and the second memory electrode layer.
3. The method of claim 2 , wherein said second multiple-layer switch structure comprises a column metal layer covering the switch layer, wherein said switch layer comprises the second phase change material layer between a first switch electrode layer and a second switch electrode layer.
4. The method of claim 2 , wherein said substantially parallel columns of said second multi-layer switch structure comprise column metal lines and second phase change material lines between first switch electrode lines and second switch electrode lines.
5. The method of claim 4 , further comprising
etching said column metal lines, said second switch electrode lines, said second phase change material lines, and said first switch electrode lines to form a plurality of switch devices at cross-points of said cross-point memory array.
6. The method of claim 2 , wherein said first multiple-layer memory structure further comprises a sacrificial layer.
7. The method of claim 6 , further comprising:
removing at least a portion of said sacrificial layer to form shallow trenches; and
filling said shallow trenches with switch bottom electrode lines.
8. The method of claim 7 , wherein said second multiple-layer switch structure comprises the second phase change material layer, the first switch electrode layer, and a column metal layer.
9. The method of claim 1 , wherein said substantially parallel rows of said first multiple-layer memory structure comprise row metal lines and first phase change material lines between first memory electrode lines and second memory electrode lines.
10. The method of claim 9 , further comprising:
etching said second memory electrode lines and said first phase change material lines to form a phase change material pattern comprising a phase change material array.
11. The method of claim 10 , further comprising:
etching said first memory electrode lines to form a plurality of memory devices at cross-points of said cross-point memory array.