In situ FTIR and surface analysis of the reaction of trimethylgallium and ammonia
Using a combination of in situ FTIR spectroscopy and detailed surface analysis, we find that TMGa decomposes at the same rate in either hydrogen or nitrogen forT < 300° C. Although ammonia does not decompose under these conditions, mixing TMGa with ammonia increases the rate of methane formation. Reacting perdeutroammonia with TMGa shows that hydrogen from the ammonia is incorporated into the product methane (whereas deuterium in the gas phase is not incorporated into the gaseous product). TMGa and ND3 do react; however, nitrogen incorporation in the growing film is temperature dependent. Further, although the decomposition of TMGa occurs in the gas phase, the last steps of the decomposition/reaction occur on the substrate surface.