US Patent 7344996 Helium-based etch process in deposition-etch-deposition gap fill

Plasma etch processes incorporating helium-based etch chemistries can remove dielectric a semiconductor applications. In particular, high density plasma chemical vapor etch-enhanced (deposition-etch-deposition) gap fill processes incorporating etch chemistries which incorporate helium as the etchant that can effectively fill high aspect ratio gaps while reducing or eliminating dielectric contamination by etchant chemical species.