A method for forming for use within an integrated circuit a gap filling sandwich composite dielectric layer construction, and an integrated circuit having formed therein the gap filling sandwich composite dielectric layer construction. To practice the method, there is first provided a substrate having formed thereover a patterned layer. There is then formed upon the patterned layer a first conformal dielectric layer through a first plasma enhanced chemical vapor deposition (PECVD) method employing a first radio frequency power optimized primarily to limit plasma induced damage to the substrate and the patterned layer. The first radio frequency power is also optimized secondarily to limit moisture permeation through the first conformal dielectric layer. There is then formed upon the first conformal dielectric layer a gap filling dielectric layer. Finally, there is formed upon the gap filling dielectric layer a second conformal dielectric layer through a second plasma enhanced chemical vapor deposition (PECVD) method employing a second radio frequency power optimized primarily to limit moisture permeation through the second conformal dielectric layer.