Thermodynamic and experimental studies of β-Ga2O3 growth by metalorganic vapor phase epitaxy

Abstract

Thermodynamic analysis and experimental demonstration of β-Ga2O3 growth by metalorganic vapor phase epitaxy using triethylgallium (TEG) and oxygen (O2) precursors were performed. Thermodynamic analysis revealed that the O2 supplied is preferentially used for the combustion of hydrocarbons and H2 derived from TEG. Therefore, the use of high growth temperatures and high input VI/III ratios is essential for the complete combustion of hydrocarbons and H2, and β-Ga2O3 growth. The use of an inert gas as the carrier gas was also determined as necessary to grow β-Ga2O3 at high temperatures. Based on these results, a (01) oriented smooth β-Ga2O3 layer could be grown on a c-plane sapphire substrate at 900 °C with a growth rate of 1.4 μm h−1 at an input VI/III ratio of 100. The grown layer showed a clear optical bandgap of 4.84 eV, and impurity concentrations of hydrogen and carbon were below the background levels of the measurement system.