Memory device with reduced-resistance interconnect

Patent metadata

Field	Value
Publication number	US-10134737-B2
Application number	US-201615384373-A
Country	US
Kind code	B2
Filing date	Dec 20, 2016
Priority date	Dec 29, 2015
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

An interconnect structure includes a lower interconnect layer, an intermediate interconnect layer, and an upper interconnect layer. First and second conductive lines in the lower interconnect layer extend generally in a first direction over a memory array region, and additional lower conductive lines in the lower interconnect layer extend generally in the first direction over a peripheral region. A first plurality of conductive line segments in the intermediate interconnect layer extend generally in the first direction over the memory array region, and additional intermediate conductive line segments in the intermediate interconnect layer extend generally in a second, perpendicular direction over the peripheral region. A second plurality of conductive line segments in the upper interconnect layer extend generally in the first direction over the memory array region, and additional upper conductive line segments in the upper interconnect layer extend generally in the first direction over the peripheral region.

First claim

What is claimed is:

1. A memory device, comprising:
a first conductive line and a second conductive line extending generally in parallel with one another within a lower interconnect layer over a row of memory cells, the first conductive line and the second conductive line being coupled to memory cells of the row;
a first plurality of conductive line segments disposed within an intermediate interconnect layer over the lower interconnect layer, wherein conductive line segments of the first plurality of conductive line segments are coupled to different locations on the first conductive line and are electrically coupled in parallel with the first conductive line;
a second plurality of conductive line segments disposed in the intermediate interconnect layer, wherein conductive line segments of the second plurality of conductive line segments are coupled to different locations on the second conductive line and are electrically coupled in parallel with the second conductive line, the second plurality of conductive line segments being geometrically parallel to the first plurality of conductive line segments;
a third plurality of conductive line segments being disposed in an upper interconnect layer disposed over the intermediate interconnect layer, wherein conductive line segments of the third plurality of conductive line segments are coupled to different locations on the first conductive line and are electrically coupled in parallel with the first conductive line; and
a fourth plurality of conductive line segments being disposed in the upper interconnect layer, wherein conductive line segments of the fourth plurality of conductive line segments are coupled to different locations on the second conductive line and are electrically coupled in parallel with the second conductive line, the fourth plurality of conductive line segments being geometrically parallel to the second plurality of conductive line segments;
wherein there is a one-to-one correspondence between a number of memory cells in the row and a sum of the first plurality of conductive line segments plus the third plurality of conductive line segments.

2. The memory device of claim 1 , wherein the lower interconnect layer is immediately adjacent to the intermediate interconnect layer with only one layer of vias electrically connecting the lower interconnect layer to the intermediate interconnect layer.

3. The memory device of claim 2 , wherein the intermediate interconnect layer is immediately adjacent to the upper interconnect layer with only one layer of vias electrically connecting the intermediate interconnect layer to the upper interconnect layer.

4. The memory device of claim 1 , wherein the lower interconnect layer is a metal1 layer, the intermediate interconnect layer is a metal2 layer, and the upper interconnect layer is a metal3 layer.

5. The memory device of claim 1 , wherein the memory device comprises a memory array region and a peripheral region spaced apart from the memory array region, wherein the first, second, third, and fourth plurality of conductive line segments are arranged generally in parallel in a first direction over the memory array region.

6. The memory device of claim 5 :
wherein the lower interconnect layer comprises the first conductive line over the memory array region and a fifth plurality of conductive line segments in the peripheral region, the fifth plurality of conductive line segments arranged in parallel with the first conductive line;
wherein the intermediate interconnect layer comprises the second plurality of conductive line segments over the memory array region and a sixth plurality of conductive line segments in the peripheral region, the sixth plurality of conductive line segments arranged perpendicular to the second plurality of conductive line segments; and
wherein the upper interconnect layer comprises the third plurality of conductive line segments over the memory array region and a seventh plurality of conductive line segments in the peripheral region, the seventh plurality of conductive line segments arranged in parallel with the third plurality of conductive line segments.

7. The memory device of claim 1 , wherein the conductive line segments of the first plurality of conductive line segments have respective first lengths which are equal to one another, and wherein the conductive line segments of the second plurality of conductive line segments have respective second lengths which are equal to one another and which are equal to the respective first lengths.

8. The memory device of claim 1 , wherein the conductive line segments of the third plurality of conductive line segments have respective third lengths which are equal to one another, and wherein the conductive line segments of the fourth plurality of conductive line segments have respective fourth lengths which are equal to one another and which are equal to the respective third lengths.

9. The memory device of claim 1 , wherein the first plurality of conductive line segments are collinear along a centerline between the first and second conductive lines, and the second plurality of conductive line segments are also collinear along the centerline between the first and second conductive lines, as viewed from over the row.

10. The memory device of claim 1 , wherein the first conductive line and the second conductive line are each coupled to each memory cell along the row.

11. A memory device, comprising:
a memory array region corresponding to an array of memory cells;
a peripheral region spaced apart from the memory array region and corresponding to peripheral circuitry operably coupled to the array of memory cells; and
an interconnect structure arranged over the memory array region and the peripheral region, the interconnect structure comprising a lower interconnect layer, an intermediate interconnect layer, and an upper interconnect layer, which are disposed in a dielectric structure;
wherein first and second conductive lines disposed in the lower interconnect layer extend generally in a first direction over the memory array region, and additional lower conductive lines disposed in the lower interconnect layer extend generally in the first direction over the peripheral region and are arranged generally in parallel with the first and second conductive lines;
wherein a first plurality of conductive line segments disposed in the intermediate interconnect layer extend generally in the first direction over the memory array region, and additional intermediate conductive line segments in the intermediate interconnect layer extend generally in a second direction, which is perpendicular to the first direction, over the peripheral region; and
wherein a second plurality of conductive line segments in the upper interconnect layer extend generally in the first direction over the memory array region, and additional upper conductive line segments in the upper interconnect layer extend generally in the first direction over the peripheral region.

12. The memory device of claim 11 , wherein the first and second conductive lines each have a first minimum line width, and a conductive line segment in at least one of the first plurality of conductive line segments or the second plurality of conductive line segments has a second minimum line width that is greater than the first minimum line width.

13. The memory device of claim 11 , wherein a first subset of the first plurality of conductive line segments are coupled electrically in parallel with the first conductive line, and a second subset of the second plurality of conductive line segments are coupled electrically in parallel with the second conductive line.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Singh Sahil Preet
• Chen Yen-Huei

Classifications

• H10W20/0698

  Local interconnections · CPC title

• H10W20/43

  Layouts of interconnections · CPC title

• H10W20/42

  Vias, e.g. via plugs · CPC title

• G11C5/025 Primary

  Geometric lay-out considerations of storage- and peripheral-blocks in a semiconductor storage device (geometrical lay-out of the components in integrated circuits, geometrical lay-out of the components in integrated circuits H10D89/10) · CPC title

• G11C7/12 Primary

  Bit line control circuits, e.g. drivers, boosters, pull-up circuits, pull-down circuits, precharging circuits, equalising circuits, for bit lines · CPC title