Patent ID: 8671878

Claim:
An apparatus for forming spacers from non-silicon oxide, silicon containing spacer layer with horizontal surfaces and sidewall surfaces over a substrate, comprising: a plasma processing chamber, comprising: a chamber wall forming a plasma processing chamber enclosure; a substrate support for supporting a substrate within the plasma processing chamber enclosure; a pressure regulator for regulating the pressure in the plasma processing chamber enclosure; at least one antenna for providing power to the plasma processing chamber enclosure for sustaining a plasma; at least one bias electrode for providing a bias voltage; a gas inlet for providing gas into the plasma processing chamber enclosure; and a gas outlet for exhausting gas from the plasma processing chamber enclosure; a gas source in fluid connection with the gas inlet, comprising; an oxygen gas source; and an anisotropic etch gas source; a controller controllably connected to the gas source, the at least one antenna, and at least one bias electrode, comprising: at least one processor; and non-transitory computer readable media having computer-executable instructions for performing a method comprising: providing a plasma oxidation treatment of a spacer layer to form a silicon oxide coating over the spacer layer, wherein the silicon oxide coating provides a horizontal silicon oxide coating on horizontal surfaces and sidewall silicon oxide coatings on sidewall surfaces of the spacer layer, the plasma oxidation treatment comprising: providing an oxygen plasma; and sputtering silicon to form silicon oxide using the oxygen plasma, wherein the sputtering of silicon deposits silicon oxide on the sidewalls to form the sidewall coatings; providing an anisotropic main etch that selectively etches horizontal surfaces of the spacer layer and silicon oxide coating with respect to sidewall surfaces of the spacer layer and the sidewall coatings of the silicon oxide coating; etching the spacer layer, wherein the sidewall coatings of the silicon oxide coating protect sidewall surfaces of the spacer layer; removing the substrate from the plasma etch chamber after etching the spacer layer, wherein the providing the plasma oxidation treatment, the anisotropic main etch, and etching the spacer layer are performed in the same plasma etch chamber using the antenna.