Thermodynamic and experimental studies of β-Ga<sub>2</sub>O<sub>3</sub> growth by metalorganic vapor phase epitaxy
Ken Goto, Kazutada Ikenaga, N. Tanaka, Masato Ishikawa, Hideaki Machida, Yoshinao Kumagai
Abstract
Abstract Thermodynamic analysis and experimental demonstration of β -Ga 2 O 3 growth by metalorganic vapor phase epitaxy using triethylgallium (TEG) and oxygen (O 2 ) precursors were performed. Thermodynamic analysis revealed that the O 2 supplied is preferentially used for the combustion of hydrocarbons and H 2 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 H 2 , and β -Ga 2 O 3 growth. The use of an inert gas as the carrier gas was also determined as necessary to grow β -Ga 2 O 3 at high temperatures. Based on these results, a ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mn>2</mml:mn> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> 01) oriented smooth β -Ga 2 O 3 layer could be grown on a c -plane sapphire substrate at 900 °C with a growth rate of 1.4 μ m 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.