Localized slots for stress relieve in copper
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorHarry Chuang
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Abstract
In accordance with the objectives of the invention a new method is provided for the creation of interconnect metal. Current industry practice is to uniformly add slots to wide and long copper interconnect lines, this to achieve improved CMP results. These slots, typically having a width in excess of 3 μm and having a length in excess of 3 μm, are added to interconnect lines having a width that is equal to or in excess of 12 μm. This approach however does not, due to its lack of selectivity of location of the slots, solve problems of localized stress that are associated with isolated single vias in the metal lines. For this reason, the invention provides for the addition of one or more localized slots adjacent to isolated vias in bottom or top metal lines that are no wider than about 2 microns.
Claims20
An integrated circuit device comprising:
- a first copper line over a substrate;
- an insulating layer overlying said first copper line;
- and
- a copper interconnect to said first copper line through an opening in said insulating layer wherein said copper interconnect comprises a single isolated via isolated from other vias formed through said insulating layer elsewhere on said substrate and an overlying second copper line wherein a slot in at least one of said first and second copper lines adjacent to said single isolated via provides stress relief at interfaces between said single isolated via and said first copper line and between said single isolated via and said second copper line.
Dependencies are inferred from the claim text.