System and method for multi-layer global bitlines
View Patent ↗A system and method for manufacturing a semiconductor device including multi-layer bitlines. The location of the bitlines in multiple layers provides for increased spacing and increased width thereby overcoming the limitations of the pitch dictated by the semiconductor fabrication process used. The bitlines locations in multiple layers thus allows the customization of the spacing and width according to the use of a semiconductor device.
1. A semiconductor device comprising:
a terminal metal layer, wherein said terminal metal layer comprises a pad to couple said semiconductor device to another semiconductor device;
a first layer and a second layer, wherein said first and said second layer are below said terminal metal layer;
a third layer, wherein said third layer comprises a plurality of data storage elements, wherein each data storage element of said plurality of data storage elements is accessible to a different bitline positioned at different layers; and
a plurality of bitlines wherein a first portion of said plurality of bitlines is in said first layer and a second portion of said plurality of bitlines is in said second layer, and wherein said first layer and said second layer are adjacent, wherein said first portion of said plurality of bitlines is further in said second layer and wherein said second portion of said plurality of bitlines is further in said first layer, wherein said first portion and said second portion of said plurality of bitlines switch layers over one or more sectors, wherein each sector has a different sector select area, and wherein a first portion of a first bitline of said first portion of said plurality of bitlines in said second layer comprises a first sub-portion of a first width and a second sub-portion of a second width.
2. The semiconductor device of claim 1 wherein said plurality of bitlines has a reduced width within a sector select area.
3. The semiconductor device of claim 1 wherein substantially equal portions of said plurality of bitlines are within said first layer and said second layer.
4. The semiconductor device of claim 1 wherein said plurality of bitlines spans one or more sectors within a single layer.
5. The semiconductor device of claim 1 wherein a horizontal pitch of a first bitline of said plurality of bitlines and second bitline of said plurality of bitlines is substantially similar to a pitch of a semiconductor fabrication process used in manufacturing said semiconductor device.
6. The semiconductor device of claim 1 wherein a width of said plurality of bitlines is increased without substantially changing the capacitance of said plurality of bitlines.
7. The semiconductor device of claim 6 wherein said width of said plurality of bitlines is customized for a target use of said semiconductor device.
8. The semiconductor device of claim 1 wherein a first distance between adjacent bitlines of said first portion of said plurality of bitlines is greater than a second distance between a first bitline of said first portion of said plurality of bitlines and a second bitline of said second portion of said plurality of bitlines.
9. The semiconductor device of claim 1 wherein said first portion of said plurality of bitlines comprises a first set of bitlines of said plurality of bitlines and wherein said second portion of said plurality of bitlines comprises a second set of bitlines of said plurality of bitlines.
10. The semiconductor device of claim 1 wherein said first portion and said second portion of the plurality of bitlines switch layers in a sector select area.
11. A memory device comprising:
a first data storage element and a second data storage element, wherein said first data storage element and said second data storage element are within a first layer, wherein said first and second data storage elements are each accessible to a different bitline positioned at different layers;
a first global bitline for accessing said first data storage element, wherein said first global bitline is within in a second layer;
a second global bitline for accessing said second data storage element, wherein said second global bitline is within a third layer, and wherein said second layer and said third layer are adjacent, wherein a first portion of said first global bitline is in said third layer and wherein a second portion of said second global bitline is in said second layer, wherein said first global bitline and said second global bitline switch layers over one or more sectors, wherein each sector has a different sector select area; and
a fourth layer, wherein said fourth layer comprises a terminal metal, wherein said fourth layer comprises a pad to couple said memory device to another memory device, and wherein said second portion of said second global bitline in second layer comprises a first sub-portion of a first width and a second sub-portion of a second width.
12. The memory device of claim 11 wherein said width of said first and said second global bitline is customized for a target application of said memory device.
13. The memory device of claim 11 wherein said first global bitline and said second global bitline span one or more sectors within a single layer.
14. The memory device of claim 11 wherein said first global bitline is further within said third layer and said second global bitline is further within said second layer.
15. A method of manufacturing a semiconductor device, comprising:
forming a first layer, wherein said first layer comprises a plurality of data storage elements, wherein each data storage element of said plurality of data storage elements is accessible to a different bitline positioned at different layers;
forming a second layer, wherein said second layer comprises a first global bitline for accessing a first portion of said plurality of data storage elements;
forming a third layer, wherein said third layer comprises a second global bitline for accessing a second portion of said plurality of data storage elements, and wherein said second layer and said third layer are adjacent; and
forming a terminal metal layer, wherein said terminal metal layer comprises a pad to couple said semiconductor device to another device, wherein said third layer further comprises a first portion of said first global bitline and wherein said second layer further comprises a second portion of said second global bitline, wherein said first global bitline and said second global bitline switch layers over one or more sectors, wherein each sector has a different sector select area, and wherein said second portion of said second global bitline in second layer comprises a first sub-portion of a first width and a second sub-portion of a second width.
16. The method of claim 15 wherein said first global bitline has a reduced width within a sector select area.
17. The method of claim 15 wherein substantially equal portions of said first global bitline and said second global bitline are within said second layer and said third layer.
18. The method of claim 15 wherein said first global bitline spans one or more sectors within a single layer.
19. The method of claim 15 wherein a width of said first global bitline is increased without substantially changing the capacitance of said first global bitline and said second global bitline, wherein said first global bitline and said second global bitline are horizontally adjacent.