Embodiments described herein generally relate to methods for processing a dielectric film on a substrate with UV energy. In one embodiment, a precursor film is deposited on the substrate, and the precursor film includes a plurality of porogen molecules. The precursor film is first exposed to UV energy at a first temperature to initiate a cross-linking process. After a first predetermined time, the temperature of the precursor film is increased to a second temperature for a second predetermined time to remove porogen molecules and to continue the cross-linking process. The resulting film is a porous low-k dielectric film having improved elastic modulus and hardness.