FOURIER-TRANSFORM INFRARED DIAGNOSTICS OF GAS-PHASE REACTIONS IN THE METALORGANIC CHEMICAL-VAPOR-DEPOSITION OF ALUMINUM FROM DIMETHYLETHYLAMINE ALANE

The gas phase reaction mechanism in the aluminum metalorganic chemical vapor deposition from dimethylethylamine alane (DMEAA) was investigat ed by Fourier transform infrared spectroscopy. DMEAA in the gas phase was dissociated into dimethylethylamine and alane even at room tempera ture and the dissociation rate was accelerated at higher gas temperatu res. Alane, produced from the dissociation of DMEAA, disappeared rapid ly and the intermediates, produced during the degradation of alane, ma y form Al particles. The dissociation reaction was found to be a first order reaction, and the activation energy was about 9.56 kcal/mol. In H-2 carrier gas, the dissociation of DMEAA was slower than that in Ar gas. The deposition rate was decreased when the substrate temperature was above 150 degrees C because DMEAA decomposed rapidly in the gas p hase. From the experimental observations, a gas phase reaction mechani sm was proposed and the degradation mechanism of liquid DMEAA was sugg ested. (C) 1998 American Vacuum Society.