An embodiment of the present invention provides methods for forming a carbon-containing layer having a low dielectric constant and good gap-fill capabilities. A method includes depositing a carbon-containing layer on a substrate and transforming the carbon-containing layer to remove at least some of the carbon. The transforming step may include annealing the carbon-containing layer in a furnace containing a hydrogen atmosphere, for example. The carbon-containing layer may be a carbon-doped silicon oxide material, where the transforming step changes the carbon-doped silicon oxide. Additionally, the method may include subjecting the annealed layer to a hydrogen and/or low oxygen plasma treatment to further remove carbon from the layer. Additionally, a step of adding a capping layer to the annealed, plasma treated material is provided. Products made by the above methods are also included, such as a product including a low k carbon-containing layer where the low k carbon-containing layer has been transformed to remove some of the carbon from the layer. An additional product includes a transformed carbon-containing layer further subjected to a hydrogen plasma treatment to remove more carbon from the layer. Further, a capping layer deposited over the transformed and hydrogen plasma treated layer is provided.