BEOL vertical fuse formed over air gap

Patent metadata

Field	Value
Publication number	US-10083908-B2
Application number	US-201715479922-A
Country	US
Kind code	B2
Filing date	Apr 5, 2017
Priority date	Feb 23, 2016
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

A method of forming an electrical device that includes forming a first level including an array of metal lines, wherein an air gap is positioned between the adjacent metal lines. A second level is formed including at least one dielectric layer atop the first level. A plurality of trench structures is formed in the at least on dielectric layer. At least one of the plurality of trench structures opens the air gap. A conductive material is formed within the trenches. The conductive material deposited in the open air gap provides a vertical fuse.

First claim

What is claimed is:

1. A method of forming an electrical device comprising:
forming an array of metal lines, wherein adjacent metal lines in said array of metal lines are separated by an air gap encapsulated in a dielectric material;
forming a trench through the dielectric material, wherein forming the trench opens at least one air gap; and
depositing an electrically conductive material in the trench to form a vertical fuse in said air gap, the vertical fuse having a neck region with a lesser width than a fuse line portion of the vertical fuse, the fuse line portion being present in the at least one air gap and the neck region positioned between the air gap and an end of the trench.

2. The method of claim 1 , wherein forming the air gap is formed by a method including depositing a dielectric cap atop and within a space separating said adjacent metal lines within the array of metal lines, wherein a thickness of the dielectric cap pinches off within the space separating said adjacent metal lines to substantially enclose the air gap.

3. The method of claim 1 , wherein said forming the trench comprises depositing at least one interlevel dielectric layer overlying a level including said air gaps and said array of metal lines, wherein the interlevel dielectric layer entirely encapsulates the air gap; forming a plurality of trenches in the interlevel dielectric layer, wherein at least one trench opens the air gap.

4. The method of claim 3 , wherein said depositing an electrically conductive material in the trenches to form a vertical fuse in an opened air gap, the vertical fuse being present in said space between adjacent metal lines.

5. The method of claim 1 , wherein forming said array of metal lines comprises:
depositing an intralevel dielectric layer on a substrate;
forming a plurality of line trenches in the intralevel dielectric layer;
filling said plurality of line trenches with a metal to provide the array of metal lines; and
recessing the interlevel dielectric layer.

6. The method of claim 2 , wherein the dielectric cap layer is deposited using a substantially conformal deposition process.

7. The method of claim 3 , wherein said forming the trench in the interlevel dielectric layer comprises forming a first trench having a first depth portion and a second depth portion, wherein the second depth portion extends to said at least one open air gap, and forming a second trench having said first depth portion.

8. The method of claim 7 , wherein the second trench does not have a second depth portion.

9. The method of claim 8 , wherein the first depth portion provides a metal line.

10. The method of claim 9 , wherein the second depth portion provides vias.

11. The method of claim 10 , wherein said vias filled with the electrically conductive material provide a first contact region and a second contact region to the vertical fuse, and the open air gap filled with the electrically conductive material provide a fuse link.

Assignees

• IBM

Inventors

• Bergendahl Marc A
• Demarest James J
• Penny Christopher J
• Waskiewicz Christopher J

Classifications

• H10W20/084

  for dual-damascene structures · CPC title

• H10W20/072

  of dielectric parts comprising air gaps · CPC title

• H10W20/46

  comprising air gaps · CPC title

• H10W20/098

  by filling between adjacent conductive parts · CPC title

• H10W20/081

  by forming openings in the dielectric parts · CPC title