Patent ID: 8765573

Claim:
A method of forming air gaps between adjacent raised features on a substrate, the method comprising: forming a hydrocarbon material in a bottom region between the adjacent raised features using a flowable deposition process, the hydrocarbon material being substantially free of silicon; forming a silicon-and-nitrogen containing film over the hydrocarbon material using a flowable chemical vapor deposition (CVD) process with a silicon precursor and a radical precursor that are substantially free of carbon, a plasma of the radical precursor generated outside a deposition region after which the radical precursor is transported to the deposition region, the radical precursor and the silicon precursor mixed in the deposition region to deposit the silicon-and-nitrogen containing film over the hydrocarbon material, the silicon-and-nitrogen containing film being substantially free of carbon and filling an upper region between the adjacent raised features and extending over the adjacent raised features; and curing the hydrocarbon material and the silicon-and-nitrogen containing material at an elevated temperature for a period of time to form the air gaps between the adjacent raised features, the elevated temperature being higher than a decomposition temperature of the hydrocarbon material, wherein the hydrocarbon material is substantially removed during the cure such that at least one of the air gaps extend from a first one of the adjacent raised features to a second one of the adjacent raised features.