INSITU RHEED OBSERVATION OF CEO2 FILM GROWTH ON SI BY LASER ABLATION DEPOSITION IN ULTRAHIGH-VACUUM

In a newly developed ultrahigh-vacuum (UHV) film preparation system equipped with in situ reflection high-energy electron diffraction (RHEED) and X-ray photoelectron spectrometer (XPS) analyzer, a sintered CeO2 target was ablated by ArF excimer laser to deposit films on Si(001), (111) and (110) substrates at temperatures ranging from 600 to 700°C. Tetravalence of the Ce in the films was confirmed by XPS, indicating that stoichiometric CeO2 was formed even in the UHV (≤10-6 Torr) condition. The orientation of deposited CeO2 films was strongly dependent on the surface state of Si substrates. The results are well explained in terms of preferential arrangement of the first plane of growing CeO2 by its interaction with substrate surface. © 1990 The Japan Society of Applied Physics.