Abstract: Embodiments of the present invention generally relate to methods and apparatus for removing unwanted deposition build-up from one more interior surfaces of a substrate processing chamber after a substrate is processed in a chamber to form, for example, Group III-V materials by metal-organic chemical vapor deposition (MOCVD) deposition processes and/or hydride vapor phase epitaxial (HVPE) deposition processes. In one embodiment, a method for removing unwanted deposition build-up from one or more interior surfaces of a substrate processing chamber is provided. The method comprises depositing one or more Group III containing layers over a substrate disposed in the substrate processing chamber, transferring the substrate out of the substrate processing chamber, and pulsing a halogen containing gas into the substrate processing chamber to remove at least a portion of the unwanted deposition build-up from one or more interior surfaces of the substrate processing chamber.