Method of selectively alloying interconnect regions by ion implantation
AssigneeAdvanced Micro Devices, Inc.
InventorsPaul R. Besser, Larry Zhao, Donggang David Wu
Life of this patent
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Abstract
A metal interconnect structure and method of making the same implants ions of an alloy elements into a copper line through a via. Then ion implantation of the alloy elements in the copper line through the via provides improved electromigration properties at the copper line at a critical electromigration failure site, without attempting to provide alloy elements throughout the entire copper line.
Claims20
A metal interconnect structure comprising:
- a copper line;
- a dielectric layer over the copper line;
- a via extending through the dielectric layer to the copper line;
- a conductive plug filling the via and contacting the copper line;
- and
- a solid solution of copper and alloy elements in the copper line only in an area of the copper line adjacent the conductive plug.
A method of selectively alloying an element to interconnect metallization, comprising the steps of:
- etching an opening through a dielectric layer to expose a portion of an underlying metallization layer;
- ion implanting alloy elements into the exposed portion of the metallization layer, a remaining portion of the metallization layer remaining substantially free of the alloy elements;
- and
- forming a solid solution of the alloy elements and the metallization layer at the exposed portion.
A method of implanting alloy elements for copper below a via at a top of a copper line covered by a dielectric layer, comprising the steps of:
- ion implanting an alloy elements into the copper line only at the top of the copper line that is exposed by the via;
- forming a conductive plug in the via;
- and
- annealing to cause formation of a solid solution of the alloy elements at the top of the copper line that is covered by the conductive plug.
A method of implanting alloy elements for copper below a via at a top of a copper line covered by a dielectric layer, comprising the steps of:
- ion implanting an alloy elements into the copper line only at the top of the copper line that is exposed by the via;
- forming a conductive plug in the via;
- annealing to cause formation of a solid solution of the alloy elements at the top of the copper line that is covered by the conductive plug;
- wherein the alloy elements is at least one of Sn, Pd, C, Ca, Mg, Al, and Hf, and the ion implantation is performed with a dosage of between about 1×1015 and about 1×1017, and an implantation energy of about 10 keV;
- and
- wherein ions of the alloy elements implant into a portion of the dielectric layer during the ion implanting of the alloy elements into the copper line, the method further comprising removing the portion of the dielectric layer into which the ions of the alloy elements implanted.
Dependencies are inferred from the claim text.