A method of treating a substrate comprises depositing silicon oxycarbide on the substrate and removing the silicon oxycarbide from the substrate. The silicon oxycarbide on the substrate is decarbonized by exposure to an energized oxygen-containing gas that heats the substrate and converts the layer of silicon oxycarbide into a layer of silicon oxide. The silicon oxide is removed by exposure to a plasma of fluorine-containing process gas. Alternatively, the remaining silicon oxide can be removed by a fluorine-containing acidic bath. In yet another version, a plasma of a fluorine-containing gas and an oxygen-containing gas is energized to remove the silicon oxycarbide from the substrate.