Within a method for forming a dielectric layer, there is first provided a substrate. There is then formed over the substrate a dielectric layer, wherein the dielectric layer is formed from a dielectric material comprising silicon, carbon and nitrogen. Preferably, a nitrogen content is graded within a thickness of the dielectric layer to provide an upper lying nitrogen rich contiguous surface layer of the dielectric layer and a lower lying nitrogen poor contiguous layer of the dielectric layer. The method contemplates a microelectronic fabrication having formed therein a dielectric layer formed in accord with the method. The method provides the resulting dielectric layer with a lower dielectric constant and enhanced adhesion properties as a substrate layer.