Embodiments of the invention generally provide a method for depositing films or layers using a UV source during a photoexcitation process. The films are deposited on a substrate and usually contain a material, such as silicon (e.g., epitaxy, crystalline, microcrystalline, polysilicon, or amorphous), silicon oxide, silicon nitride, silicon oxynitride, or other silicon-containing materials. The photoexcitation process may expose the substrate and/or gases to an energy beam or flux prior to, during, or subsequent a deposition process. Therefore, the photoexcitation process may be used to pre-treat or post-treat the substrate or material, to deposit the silicon-containing material, and to enhance chamber cleaning processes. Attributes of the method that are enhanced by the UV photoexcitation process include removing native oxides prior to deposition, removing volatiles from deposited films, increasing surface energy of the deposited films, increasing the excitation energy of precursors, reducing deposition time, and reducing deposition temperature.