Epitaxial growth of CeO 2 on (100) InP using reactive r.f. magnetron sputtering

Abstract

The epitaxial growth of CeO2 thin films has been realized on (100) InP substrates using reactive r.f. magnetron sputtering. Oxide films were nucleated in the presence of molecular hydrogen (4% H2/Ar sputtering gas) in order to reduce the native oxide formation on the InP surface, which interferes with CeO2 epitaxy. A metal cerium target was used as the cation source, with water vapor serving as the oxidizing species. Epitaxial films were sputter-deposited at a substrate temperature of 550 °C in a H2O vapor pressure of approximately 10-3 Torr. Crystallinity of the oxide films was examined using θ–2θ X-ray diffraction, ω-rocking curves, and in-plane φ-scans. The best results were obtained when the initial nucleation layer was deposited with P(H2O)<10-5 Torr, followed by deposition at P(H2O)=10-3 Torr. The epitaxial growth of CeO2 on InP could prove enabling in efforts to integrate functional oxides with InP-based optoelectronic and microwave technologies.