Methods and apparatus for producing stable low k FSG film for HDP-CVD

The present invention relates to the manufacture of integrated circuits, and more specifically, to methods, apparatus and systems for forming fluorinated silicate glass ("FSG") films with improved characteristics in a high-density-plasma chemical-vapor-deposition ("HDP-CVD") environment. Methods and apparatus of the present invention deposit fluorinated silicate glass (FSG) in such a manner that it strongly adheres to an overlying or underlying barrier layer or etch stop layer, and has a lower dielectric constant, among other benefits. In one embodiment, silicon tetrafluoride (SiF), oxygen (O), and argon (Ar) are used as the reactant gases, with the ratio of oxygen to silicon controlled to be at between about 2:1 to 6:1. Such Olevels help reduce the amount of degradation of ceramic chamber components otherwise caused by the elimination of silane from the process recipe.