Thin film growth of gadolinia by metal-organic chemical vapour deposition (MOCVD)

We report the growth of thin films of gadolinia using metal-organic chemical vapour deposition (MOCVD) under reduced pressure, The mixed ligand complex [{Gd(tmhd)(3)}(2)(tetraglyme)], where tmhd-H is 2,2,6,6-tetramethyl-3,5-heptanedione and tetraglyme is tetraethylene glycol dimethyl ether, was used as precursor. Silicon wafers with a (100) orientation were used as substrates. The work described can be considered as a preliminary stage in the eventual manufacture of solid electrolytes with a mixed metal composition oi Ce0.9Gd0.1O1.95 and, as such, certain process parameters are restricted by limits associated with potential cerium precursors which are reported in a separate paper. The effects oi the deposition conditions on the structure and composition of the resulting oxide films are presented. The dependence of growth on parameters such as the evaporation rate, moist oxygen flow rate and substrate temperature (T-sub) is discussed. Characterization of the microstructure using scanning electron microscopy (SEM) and X-ray diffraction (XRD) confirms the first reported growth, to our knowledge, oi thin, uniform layers of gadolinia by the CVD technique.