Abstract: An interconnect opening of an integrated circuit is filled with a conductive fill, such as copper, with the interconnect opening being within an insulating layer on a semiconductor wafer. A seed layer of a first alloy is deposited conformally onto sidewalls and a bottom wall of the interconnect opening. The first alloy is comprised of a first metal dopant in a bulk conductive material. The first metal dopant has a relatively high solid solubility in the bulk conductive material, and the first metal dopant has a concentration in the bulk conductive material of the seed layer that is lower than the solid solubility of the first metal dopant in the bulk conductive material.

Abstract: In a method for filling an interconnect opening to form an interconnect of an integrated circuit, the interconnect opening is formed within an insulating layer. The interconnect opening is partially filled with a conductive material to form a recess within the conductive material toward a top of the interconnect opening, and the recess is disposed within the interconnect opening. An alloy is conformally deposited to fill the recess. Any conductive material and the alloy on the insulating layer are polished away such that the conductive material and the alloy are contained within the interconnect opening. A thermal anneal is then performed such that the conductive material and the alloy form into a conductive fill of a single grain structure within the interconnect opening. An additional encapsulating material is formed to cover a top surface of the conductive fill during the thermal anneal from the dopant of the alloy diffusing out of the alloy and along the top surface of the conductive fill.

Abstract: An alloy precipitate is formed to surround a conductive fill within an interconnect opening, including especially a top surface of the conductive fill, to prevent drift of material from the conductive fill into the insulating layer that is surrounding the interconnect opening. An alloy material is deposited non-conformally such that the alloy material is deposited substantially only toward a top of the sidewalls of an interconnect opening and substantially only toward a center of the bottom wall of the interconnect opening. The interconnect opening is filled with the conductive material by growing the conductive material from a seed layer of the conductive material to form a conductive fill of the conductive material within the interconnect opening. The semiconductor wafer is heated to anneal the conductive fill within the interconnect opening such that the conductive fill forms into a substantially single grain structure.