Growth of Sr1−xBaxF2 films on InAs by molecular beam epitaxy

Abstract

Heteroepitaxial films of Sr1−x BaxF2 have been deposited onto (001), (110), and (111)B oriented InAs substrates by molecular beam epitaxy. The epitaxial growth was studied by reflection high energy electron diffraction (RHEED), electron microscopy, x-ray diffraction, and secondary ion mass spectrometry (SIMS). The films grown epitaxially on the (001) and (110) substrates exhibit {111} faceting, and smooth and featureless growth occurs only on the (111)B oriented substrates. Single crystalline Sr1−x BaxF2 films lattice-matched to the InAs substrates are grown at temperatures higher than 200, 450, and 400 °C on the (001), (110), and (111)B faces, respectively. SIMS profiles indicate that the interdiffusion between epitaxial film and substrate is rather small even at a growth temperature of 520 °C. The change in RHEED patterns during the thermal cleaning of substrate surfaces is also described.