Embodiments described herein provide a method for sealing a porous low-k dielectric film. The method includes forming a sealing layer on the porous low-k dielectric film using a cyclic process. The cyclic process includes repeating a sequence of depositing a sealing layer on the porous low-k dielectric film and treating the sealing layer until the sealing layer achieves a predetermined thickness. The treating of each intermediate sealing layer generates more reactive sites on the surface of each intermediate sealing layer, which improves the quality of the resulting sealing layer.