Transportation in MOCVD of traces of oxygenated aluminum and gallium organometallics

Gas-phase transportation of dimethylmethoxy compounds of aluminum and gallium, which contaminate corresponding trimethyl metal compounds used in MOCVD, were investigated. It was found that larger amounts of oxygenated compounds were transported than can be calculated from the vapor pressure ratio of Me2MOMe (I) to Me3M (II). A decrease in the ratio (m/n) of the concentration of oxygenated compound (m) in the bubbler to the concentration of that transported to the reactor (n) was observed, especially at very low content of I in Me3M. The 1H-NMR and cryometric studies strongly suggest that an equilibrium between the system of trimeric dimethylmetal methoxy compound (Me3M)n and mixed species