Formation of alloy material using alternating depositions of alloy doping element and bulk material

Abstract

An alloy material is formed on an underlying material, and the alloy material comprises an alloy doping element mixed into a bulk material. A first layer of material including the alloy doping element is deposited on the underlying material using a first type of deposition process. The first type of deposition process is corrosion resistive to the underlying material according to one aspect of the present invention. A second layer of material including the bulk material is deposited on the first layer of material using a second type of deposition process. A thermal anneal may be performed by heating the first layer of material and the second layer of material such that the alloy doping element is mixed into the bulk material to form the alloy material on the underlying material. The alloy doping element of the first layer of material deposited on the underlying material promotes adhesion of the alloy material to the underlying material. The present invention may be used to particular advantage when the underlying material is a diffusion barrier material deposited on sidewalls and a bottom wall of an interconnect opening, and when the alloy material is a copper alloy formed on the diffusion barrier material. In this manner, a plurality of deposition processes are used for forming a stack of layers of materials comprising the alloy material. The first type of deposition process for depositing the first layer of material on the underlying material is corrosion resistive to the underlying material. Corrosion to the underlying material is undesired because corrosion to the underlying material may degrade the adhesion of the interconnect to the underlying material to increase undesired electromigration failure of the interconnect. The second deposition process for depositing the second layer of material on the first layer of material may be a faster deposition process for depositing the bulk material of the alloy.

Dependencies are inferred from the claim text.