A method of forming a silicon oxide layer on a substrate. The method includes providing a substrate and forming a first silicon oxide layer overlying at least a portion of the substrate, the first silicon oxide layer including residual water, hydroxyl groups, and carbon species. The method further includes exposing the first silicon oxide layer to a plurality of silicon-containing species to form a plurality of amorphous silicon components being partially intermixed with the first silicon oxide layer. Additionally, the method includes annealing the first silicon oxide layer partially intermixed with the plurality of amorphous silicon components in an oxidative environment to form a second silicon oxide layer on the substrate. At least a portion of amorphous silicon components are oxidized to become part of the second silicon oxide layer and unreacted residual hydroxyl groups and carbon species in the second silicon oxide layer are substantially removed.