CRYSTALLINE QUALITY AND SURFACE-MORPHOLOGY OF (100)CEO2 THIN-FILMS GROWN ON SAPPHIRE SUBSTRATES BY SOLID SOURCE METALORGANIC CHEMICAL-VAPOR-DEPOSITION

(100)-oriented, cerium oxide epitaxial thin films, approximately 250 Angstrom thick, were grown on r-plane sapphire substrates using a solid source MOCVD technique. Rocking curve FWHM values as low as 0.63 degrees and AFM surface roughness on the order of 5 Angstrom RMS were obtained with substrate temperatures near 680 degrees C and growth rates of 0.13 Angstrom/s. Lower substrate temperatures and higher metalorganic source feed rates resulted in rougher layers, which had broader XRD rocking curve widths, indicating poorer out-of-plane alignment. RES channeling spectra showed that the best films had high crystalline quality: only at the film-substrate interface were slight distortions due to lattice or thermal expansion mismatch detected.