Implementations disclosed herein relate to methods for controlling substrate outgassing of hazardous gasses after an epitaxial process. In one implementation, the method includes providing a substrate comprising an epitaxial layer into a transfer chamber, wherein the transfer chamber has an ultraviolet (UV) lamp module disposed adjacent to a top ceiling of the transfer chamber, flowing an oxygen-containing gas into the transfer chamber through a gas line of the transfer chamber, flowing a non-reactive gas into the transfer chamber through the gas line of the transfer chamber, activating the UV lamp module to oxidize residues or species on a surface of the substrate to form an outgassing barrier layer on the surface of the substrate, ceasing the flow of the oxygen-containing gas and the nitrogen-containing gas into the transfer chamber, pumping the transfer chamber, and deactivating the UV lamp module.