Abstract: A method and structure for protecting a flowable oxide insulator in a semiconductor by oxidizing sidewalls of the FOX insulator, optionally nitridizing the oxidized FOX sidewalls, and then covering all surfaces of a trough or plurality of troughs in the FOX insulator, including the sidewalls, with a conductive secondary protective layer. In a multiple layer damascene structure, the surface of the FOX insulator is also oxidized, an additional oxide layer is deposited thereon, and a nitride layer deposited on the oxide layer. Then steps are repeated to obtain a comparable damascene structure. The materials can vary and each damascene layer nay be either a single damascene or a dual damascene layer.

Abstract: An insulator for covering an interconnection wiring level in a surface thereof on a semiconductor substrate containing semiconductor devices formed by curing a flowable oxide layer and annealing is provided. The annealing is carried out in the presence of hydrogen and aluminum to obtain a dielectric constant of the oxide layer to a value below 3.2. Also provided is electrical insulation between neighboring devices using the flowable oxide which is cured and annealed. In this case, the annealing can be carried out in hydrogen with or without the presence of aluminum.