High-throughput thermodynamic analysis of epitaxial growth of β-Ga2O3 by the chemical vapor deposition method from TMGa-H2O system

A comprehensive thermodynamic study of CVD beta-Ga2O3 epitaxial films from TMGa-H2O (trimethylgalliumwater) system is performed with a wide experimental condition range and high mesh grid number. The highthroughput computational approach was utilized, investigating the effects of temperature (500-1500 K), pressure (0-100,000 Pa) and H2O fraction (0-100%) on equilibrium condensed phase purity and gas speciation. The beta-Ga2O3 growth regime expands with increasing temperature and H2O fraction. High purity (>99%) beta-Ga2O3 is predicted under high H2O fractions (>80%) and temperatures from 1000-1300 K. And the dominant Ga species are Ga(g), Ga(OH) and Ga2O, while H2O, CO2 and CO carry O. Median temperatures of 1000-1200 K maximize TMGa conversion efficiency while minimizing graphite formation. The computations yield optimal CVD conditions of 1000-1200 K, 2000-10000 Pa, and VI: III> 7 for high quality beta-Ga2O3 epitaxial growth, providing useful guidance for further experimental CVD process development.