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 Å thick, were grown on r-plane sapphire substrates using a solid source MOCVD technique. Rocking curve FWHM values as low as 0.63° and AFM surface roughness on the order of 5 Å RMS were obtained with substrate temperatures near 680°C and growth rates of 0.13 Å/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. RBS 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.