Abstract: A showerhead adapted for distributing gases into a process chamber and a method for forming dielectric layers on a substrate are generally provided. In one embodiment, a showerhead for distributing gases in a processing chamber includes an annular body coupled between a disk and a mounting flange. The disk has a plurality of holes formed therethrough. A lip extends from a side of the disk opposite the annular body and away from the mounting flange. The showerhead may be used for the deposition of dielectric materials on a substrate. In one embodiment, silicon nitride and silicon oxide layers are formed on the substrate without removing the substrate from a processing chamber utilizing the showerhead of the present invention.