| abstract |
A method for processing a substrate is provided, wherein a first organosilicon precursor, a second organosilicon precursor, a porogen, and an oxygen source are provided to a processing chamber. The first organosilicon precursor comprises compounds having generally low carbon content. The second organosilicon precursor comprises compounds having higher carbon content. The porogen comprises hydrocarbon compounds. RF power is applied to deposit a film on the substrate, and the flow rates of the various reactant streams are adjusted to change the carbon content as portions of the film are deposited. In one embodiment, an initial portion of the deposited film has a low carbon content, and is therefore oxide-like, while successive portions have higher carbon content, becoming oxycarbide-like. Another embodiment features no oxide-like initial portion. Post-treating the film generates pores in portions of the film having higher carbon content. |