A method for processing a substrate in a plasma processing system having a showerhead and a shower-pedestal oriented below the showerhead is provided. The method includes supporting the substrate between the showerhead and the shower-pedestal. The substrate is supported to be spaced apart from the shower-pedestal and the shower head. The method includes flowing a process gas out of the shower-pedestal in a direction that is toward a backside of the substrate, and flowing an inert gas out of the showerhead in a direction that is toward a topside of the substrate. The method includes generating a plasma, using the process gas, between the shower-pedestal and the backside of the substrate. The plasma is configured to deposit a film on said backside of the substrate and the inert gas is configured to prevent or reduce deposition on said topside of the substrate.