Growth Mechanism of Epitaxial Oxide Films by Laser MBE

Abstract

ABSTRACTCrystallographic structure and valence state of CeO2 and Nd2-O3 films deposited by laser MBE on Si substrates were investigated by reflection high energy electron diffraction (RHEED) and X-ray photoelectron spectroscopy (XPS). In contrast with epitaxial growth of CeO2 (111) and Nd2O3(111) on Si (111), epitaxial films were not obtained on Si(001). Partially reduced mixed valence (4+ and 3+) Ce was indicated to exist by XPS in the cerium oxide film within 2nm from the interface with Si. Beyond this transition layer, two-dimensional growth of CeO2 film on Si(111) was verified from in situ RHEED and as well as on Si(001) from XPS measurements.