Embodiments of the invention generally provide a method for depositing films using photoexcitation. The photoexcitation may be utilized for at least one of treating the substrate prior to deposition, treating substrate and/or gases during deposition, treating a deposited film, or for enhancing chamber cleaning. In one embodiment, a method for depositing silicon and nitrogen-containing film on a substrate includes heating a substrate disposed in a processing chamber, generating a beam of energy of between about 1 to about 10 eV, transferring the energy to a surface of the substrate; flowing a nitrogen-containing chemical into the processing chamber, flowing a silicon-containing chemical with silicon-nitrogen bonds into the processing chamber, and depositing a silicon and nitrogen-containing film on the substrate.