Profile and CD uniformity control by plasma oxidation treatment

A method forming spacers from a non-silicon oxide, silicon containing spacer layer with horizontal surfaces and sidewall surfaces over a substrate, comprising:

• (a) forming a silicon oxide layer over plasma etch chamber surfaces before placing the substrate in the plasma etch chamber;
• (b) providing a plasma treatment to form a silicon oxide coating over the spacer layer, wherein the silicon oxide coating provides a horizontal coating on the horizontal surfaces and sidewall coatings on the sidewall surfaces of the spacer layer, wherein the plasma treatment sputters silicon oxide from the plasma etch chamber to provide silicon for the silicon oxide layer formed during the plasma treatment;
• (c) 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;
• and
• (d) etching the spacer layer, wherein the sidewall coatings of the silicon oxide coating protect sidewall surfaces of the spacer layer.

A method for forming spacers from a non-silicon oxide, silicon containing spacer layers with horizontal surfaces and sidewall surfaces over a plurality of substrates, comprising:

• (a) forming a silicon oxide layer over plasma etch chamber surfaces before placing a substrate in the plasma etch chamber;
• (b) placing a substrate of the plurality of substrates with a spacer layer that is silicon containing but non-silicon oxide containing in a plasma etch chamber before providing the plasma oxidation treatment, wherein the chamber has an antenna;
• (c) providing a plasma oxidation treatment to form a silicon oxide coating over the spacer layer, wherein the silicon oxide coating provides a horizontal coating on the horizontal surfaces and sidewall coatings on the sidewall surfaces of the spacer layer, comprising:
• providing an oxygen plasma;
• and
• sputtering silicon to form silicon oxide with the oxygen plasma, wherein the plasma oxidation treatment sputters silicon oxide from the plasma etch chamber to provide silicon for the silicon oxide layer formed during the plasma oxidation treatment;
• (d) providing a 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;
• (e) etching the spacer layer, wherein the sidewall coatings of the silicon oxide coating protect sidewall surfaces of the spacer layer;
• (f) removing the substrate from the plasma etch chamber after etching the spacer layer, wherein the providing the plasma oxidation treatment, providing the anisotropic main etch, and etching the spacer layer are performed in the same plasma etch chamber using the antenna;
• (g) repeating steps (a) to (f) until each of the plurality of substrates is processed.

A method forming spacers from a non-silicon oxide, silicon containing spacer layer with horizontal surfaces and sidewall surfaces over a substrate, comprising:

• (a) providing a plasma oxidation treatment to form a silicon oxide coating over the spacer layer, wherein the silicon oxide coating provides a horizontal coating on the horizontal surfaces and sidewall coatings on the sidewall surfaces of the spacer layer, wherein the providing the plasma oxidation treatment, comprises:
• providing an oxygen plasma;
• and
• sputtering silicon to form silicon oxide with the oxygen plasma, wherein the sputtered silicon deposits on the sidewalls to form the sidewall coatings;
• (b) 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;
• and
• (c) etching the spacer layer, wherein the sidewall coatings of the silicon oxide coating protect sidewall surfaces of the spacer layer.