Anti-reflective coatings for use at 248 nm and 193 nm

The present invention is directed to a silicon carbide anti-reflective coating (ARC) and a silicon oxycarbide ARC. Another embodiment is directed to a silicon oxycarbide ARC that is treated with oxygen plasma. The invention includes method embodiments for forming silicon carbide layers and silicon oxycarbide layers as ARC's on a semiconductor substrate surface. Particularly, the methods include introducing methyl silane materials into a process chamber where they are ignited as plasma and deposited onto the substrate surface as silicon carbide. Another method includes introducing methyl silane precursor materials with an inert carrier gas into the process chamber with oxygen. These materials are ignited into a plasma, and silicon oxycarbide material is deposited onto the substrate. By regulating the oxygen flow rate, the optical properties of the silicon oxycarbide layer can be adjusted. In another embodiment, the silicon oxycarbide layer can be treated with oxygen plasma.