Low resistance and reliable copper interconnects by variable doping

摘要

A method and system is provided for efficiently varying the composition of the metal interconnects for a semiconductor device. A metal interconnect according to the present disclosure has an intermediate layer on a dielectric material, the intermediate layer having a relatively higher concentration of an impurity metal along with a primary metal, the impurity metal having a lower reduction potential than the primary metal. The metal interconnect has a main layer of the metal alloy interconnect on top of the intermediate layer and surrounded by the intermediate layer, the main layer having a relatively higher concentration of the primary metal than the intermediate layer, wherein the intermediate and main layers of the metal alloy interconnect each maintains a material uniformity.

主权项

1. A method for fabricating a metal alloy interconnect in a semiconductor device, the method comprising:
defining an interconnect boundary profile, comprising vias or trenches, on a substrate material; plating a primary metal and one or more impurity metals together to form a first layer of interconnect along the interconnect boundary profile, wherein the first layer of interconnect comprising a primary metal and one or more impurity metals; and plating a primary metal and one or more impurity metals together to form a second layer of interconnect over the first layer of interconnect, wherein the second layer of interconnect comprising the primary metal with one or more impurity metals, wherein the second layer of interconnect is thicker than the first layer of interconnect and the second layer of interconnect has a lower electrical resistance than the first layer of interconnect.