Patent ID: 7351285

Claim:
A method for forming a seed layer in a process chamber containing a showerhead, the showerhead comprising an inner gas delivery zone and an outer gas delivery zone, the method comprising: providing a substrate in said process chamber with a center of the substrate generally aligned with the inner gas delivery zone and an edge of the substrate generally aligned with the outer gas delivery zone; and depositing a variable thickness Ru seed layer on the substrate by: exposing the substrate to a first gas flowed through the inner gas delivery zone, the first gas comprising Ru 3 (CO) 12 in a first amount and carbon monoxide, and exposing the substrate to a second gas flowed through the outer gas delivery zone, the second gas comprising Ru 3 (CO) 12 in a second amount between zero and a value less than the first amount, and an inert gas or carbon monoxide, or a combination thereof, whereby the Ru seed layer is deposited with a thickness at the edge of the substrate that is less than a thickness at the center of the substrate.