Noble metal layer formation for copper film deposition

A method of forming an interconnect structure, comprising:

• (a) providing a substrate structure to a process chamber;
• wherein the substrate structure includes an insulating material layer having vias defined therethrough to a contact metal;
• (b) forming a tungsten-containing barrier layer on the contact metal inside the vias;
• (c) forming a cobalt metal layer on the tungsten-containing barrier layer using a cyclical deposition process, wherein the cyclical deposition process includes a plurality of cycles and wherein each cycle comprises establishing a flow of an inert gas in the process chamber and modulating the flow of the inert gas with alternating periods of exposure to one of a cobalt metal-containing precursor and a silane-containing reducing gas;
• wherein the cobalt metal-containing precursor is selected from the group consisting of (cyclopentadienyl)(cyclohexadienyl) cobalt, (cyclobutadienyl)(cyclopentadienyl) cobalt, bis(cyclopentadienyl) cobalt, bis(methylcyclopentadienyl) cobalt, cyclopentadienyl(1,3-hexadienyl) cobalt, (cyclopentadienyl)(5-methylcyclopentadienyl) cobalt, and bis(ethylene) (pentamethylcyclopentadienyl) cobalt;
• and
• (d) depositing a copper layer on the cobalt metal layer.