Patent ID: 7700484

Claim:
A method of filling nano-sized features of a substrate using a deposition system including a processing chamber, a gas supply system coupled to the processing chamber, an inductively coupled plasma (ICP) source coupled to the processing chamber, a copper target coupled to the processing chamber, a DC source coupled to the copper target, a substrate holder coupled to the processing chamber, an RF bias generator coupled to the substrate holder for supporting the substrate, and a backside gas supply system coupled to the substrate holder, the method comprising performing consecutive first and second dry-filling processes by: performing the first dry-filling process with a first backside pressure applied to the substrate to maintain the substrate at below room temperature, the performing of the first dry-filling process comprising: (a) creating a first dry-filling plasma with a first DC power level provided by the DC source to the copper target for sputtering copper from the copper target; and (b) depositing a seed layer of metal at a first rate into the nano-sized features of the substrate by the net positive deposition of a first amount of low-resistivity copper from the copper within the first dry-filling plasma; then performing the second dry-filling process with a second backside pressure applied to the substrate, the second backside pressure being sufficiently lower than the first backside pressure so as to increase the surface mobility of the deposited low-resistivity copper on the sidewalls during the second dry-filling process and create a bottom-up filling process, the performing of the second dry-filling process comprising: (a) creating a second dry-filling plasma with a second DC power level provided by the DC source to the copper target for sputtering copper from the copper target; and (b) depositing a second amount of low-resistivity copper at a second rate into the nano-sized features of the substrate by depositing the second amount of low-resistivity copper from the copper within the second dry-filling plasma; then (c) creating a shaping plasma with a third DC power level provided by the DC source to the copper target, the third DC power level being lower than the first and second DC power levels.