Thermodynamic analysis of trimethylgallium decomposition during GaN metal organic vapor phase epitaxy

We analyzed the decomposition of Ga(CH3)(3) (TMG) during the metal organic vapor phase epitaxy (MOVPE) of GaN on the basis of first-principles calculations and thermodynamic analysis. We performed activation energy calculations of TMG decomposition and determined the main reaction processes of TMG during GaN MOVPE. We found that TMG reacts with the H-2 carrier gas and that (CH3)(2)GaH is generated after the desorption of the methyl group. Next, (CH3)(2)GaH decomposes into (CH3)GaH2 and this decomposes into GaH3. Finally, GaH3 becomes GaH. In the MOVPE growth of GaN, TMG decomposes into GaH by the successive desorption of its methyl groups. The results presented here concur with recent high-resolution mass spectroscopy results. (C) 2018 The Japan Society of Applied Physics