In situ optical monitoring of layer composition in the chemical beam epitaxy of AlGaAs from amine-alane sources

Normal incidence in situ laser reflectometry (LR) was used to give reliable quantitative composition and thickness information during epitaxial growth of GaAs, AlGaAs, and AlAs by chemical beam epitaxy. AlGaAs layers grown using amine-alane sources showed variations in growth rate and composition arising from instabilities in the source. In the case of dimethylethylamine-alane, the growth rate varied from run to run, between layers in a multilayer structure and during the growth of thick AlGaAs layers. The use of LR gave a rapid indication of the problem, which was solved by using trimethylamine-alane as a source.[PUBLICATION ABSTRACT]