ON THE THERMAL-DECOMPOSITION OF TRIMETHYLGALLIUM - A MOLECULAR-BEAM SAMPLING MASS-SPECTROSCOPY STUDY

Thermal decomposition of trimethylgallium in H2, N2, and their admixtures is studied using molecular beam sampling mass spectrometry. Methane and ethane are found as the primary volatile byproducts of decomposition. The relative amount of CH4 increases and C2H6 decreases with an increase in H2 concentration relative to N2. The activation energy for the rupture of the first Ga-methyl bond is found to be E1a = 64.6 kcal/mol. The activation energies for the rupture of the second and third Ga-methyl bonds are estimated to be E1b = 52.6 kcal/mol and E1c = 54.1 kcal/mol. Our data reinforce a radical mechanism where TMGa decomposes by way of successively releasing its three methyl radicals.