An apparatus for forming spacers is provided. A plasma processing chamber is provided, comprising a chamber wall, a substrate support, a pressure regulator, an antenna, a bias electrode, a gas inlet, and a gas outlet. A gas source comprises an oxygen gas source and an anisotropic etch gas source. A controller comprises a processor and computer readable media. The computer readable media comprises computer readable code for placing a substrate of the plurality of substrates in a plasma etch chamber, computer readable code for providing a plasma oxidation treatment to form a silicon oxide coating over the spacer layer, computer readable code for sputtering silicon to form silicon oxide with the oxygen plasma, computer readable code for providing an anisotropic main etch, computer readable code for etching the spacer layer, computer readable code for removing the substrate from the plasma etch chamber after etching the spacer layer.