In one embodiment a method for fabricating a compound nitride semiconductor device comprising positioning one or more substrates on a susceptor in a processing region of a metal organic chemical vapor deposition (MOCVD) chamber comprising a showerhead, depositing a gallium nitride layer over the substrate with a thermal chemical-vapor-deposition process within the MOCVD chamber by flowing a first gallium containing precursor and a first nitrogen containing precursor through the showerhead into the MOCVD chamber, removing the one or more substrates from the MOCVD chamber without exposing the one or more substrates to atmosphere, flowing a chlorine gas into the processing chamber to remove contaminants from the showerhead, transferring the one or more substrates into the MOCVD chamber after removing contaminants from the showerhead, and depositing an InGaN layer over the GaN layer with a thermal chemical-vapor-deposition process within the MOCVD chamber is provided.