Apparatus, systems, and methods for processing workpieces are provided. In one example implementation, a fluorine and oxygen plasma-based process can be used to smooth a roughened surface of a silicon and/or a silicon containing structure. The process can include generating species from a process gas using an inductive coupling element in a first chamber. The process can include introducing a fluorine containing gas and an oxygen containing gas with the species to create a mixture. The process can further include exposing the silicon and/or the silicon containing structure to the mixture such that the mixture at least partially etches a roughened portion to leave a smoother surface of the silicon and/or the silicon containing structure.