Effect of Oxygen Radicals for Epitaxial Growth of Al2O3 on Si

Abstract
Epitaxial Al2O3 films were grown on Si substrates by metal-organic molecular beam epitaxy (MOMBE) using oxygen radicals excited with remote rf plasma and trimethylaluminum (TMA) as source gases. The epitaxial temperature of Al2O3 on Si decreased from 800° C to 700° C using this method. The growth rate of the Al2O3 films increased 1.4–1.6 times at excitation rf power of 400 W, compared with that without rf plasma excitation. The Auger electron spectroscopy (AES) measurement showed that the carbon contamination in the Al2O3 film was removed by the oxygen radicals during the growth. The flatness of the grown Al2O3 surface was improved using oxygen radicals.