Negative effect of arsenic on indium composition of InGaN grown by metalorganic chemical vapor deposition

InGaN/GaN multiple quantum-well structures and In-GaN/GaN multilayers were grown on GaN/sapphire Substrates by low-pressure metalorganic chemical vapor deposition. As the tertiarybutylarsine flow rate increased, we observed various unexpected structural and optical results. These results were attributed to the reduction of In composition in InGaN from 10% to 3.7% with an increase of the TBA flow rate up to 1 mu mol/min, as characterized by secondary ion mass spectrometry. Interestingly, the As concentration was also reduced slightly, accompanying the decrease in In composition. This unexpected result came from changed surface kinetics not from a gas-phase reaction. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim