GROWTH, STRUCTURAL CHARACTERIZATION AND INTERFACIAL REACTION OF MAGNETRON SPUTTERED CeO2 THIN FILMS ON DIFFERENT SUBSTRATES

Abstract

CeO 2 thin films were deposited on Si , Al , Ti –6 Al –4 V alloy, Si 3 N 4 and glass substrates by magnetron sputtering at room temperature. Growth of CeO 2 films on Si and Si 3 N 4 and effect of annealing were investigated by XRD, FESEM and AFM. Interaction between deposited CeO 2 films and Si , Al , Ti –6 Al –4 V alloy, Si 3 N 4 and glass substrates was investigated by XPS. XRD studies show that films are oriented preferentially to (200)-direction of CeO 2 and no significant change is observed in the XRD patterns of films after heat treatment. CeO 2 film on Si 3 N 4 exhibits rough morphology, whereas very fine morphology is observed in CeO 2 film on Si . CeO 2 film on Si shows lower roughness in relation to that on Si 3 N 4 as demonstrated by AFM studies. XPS results show that Ce is present as both +4 and +3 oxidation states in CeO 2 film deposited on Si and Al substrates, whereas Ce 4+ is the main species in CeO 2 films deposited on Ti –6 Al –4 V alloy, Si 3 N 4 and glass substrates. Ce3d , Si2p and O1s core level spectra demonstrate that Ce 2 O 3 or cerium silicate and SiO x type of species are formed at the interface of CeO 2 and Si . Similarly, formation of interfacial species like Ce 2 O 3 or cerium aluminate is evident in CeO 2 film on Al as demonstrated by XPS studies. On the other hand, interfacial reactions between CeO 2 and Ti –6 Al –4 V alloy, Si 3 N 4 and glass substrates are limited in the respective films.