The use of Ce(fod)4 as a precursor for the growth of ceria films by metal-organic chemical vapour deposition

We report the growth of thin films of cerium oxide using the metal-organic chemical vapour deposition (MOCVD) technique. The homoleptic complex, Ce(fod)₄, where fod-H is 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dione, was used as a precursor. Silicon wafers with a (100) orientation were used as substrates. This work can be considered a feasibility study of this precursor as a potential source of ceria for the eventual production of solid solutions with a stoichiometry of Ce_0.9Gd_0.1O_1.95. These ceramic films are intended for use as electrolytes in solid oxide fuel cells (SOFCs). In this paper, the difficulties associated with CVD growth of oxide films using solid phase precursors such as Ce(fod)₄ which contain fluorinated ligands are discussed as well as the methods used to eliminate such problems. The variation of important CVD parameters such as moist oxygen flow rate are discussed in terms of their effect on the growth rate and the elemental composition of the deposited films. Analysis was carried out using techniques such as scanning electron microscopy, X-ray photoelectron spectroscopy and X-ray fluorescence.