US Patent 11276560 Spacer etching process

Systems and methods for processing a workpiece are provided. In one example, a method includes placing a workpiece on a workpiece support in a processing chamber. The workpiece has at least one material layer and at least one structure thereon. The method includes admitting a process gas into a plasma chamber, generating one or more species from the process gas, and filtering the one or more species to create a filtered mixture. The method further includes providing RF power to a bias electrode to generate a second mixture and exposing the workpiece to the second mixture to etch a least a portion of the material layer and to form a film on at least a portion of the material layer.