Zr(IV) and Hf(IV) β-diketonate complexes as precursors for the photochemical deposition of ZrO2 and HfO2 thin films

Abstract In this paper amorphous ZrO 2 and HfO 2 thin films were obtained by direct UV irradiation of Zr(IV) and Hf(IV) β-diketonate precursor complexes on Si(1 0 0) and fused silica substrates. The precursors, Zr(CH 3 COCHCOCH 3 ) 4 and Hf(C 6 H 5 COCHCOCH 3 ) 4 were deposited as amorphous thin films by spin coating. The photochemistry of these films was monitored by FT-IR spectroscopy. The photolysis with 254 nm light led to the loss of the ligands from the coordination complexes, and the production of metallic oxides. The thin films products were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). These analyses revealed that as-deposited films are amorphous and that the presence of carbon is thought to arise from the ligands. However, post-annealing of the photodeposited films favors the stoichiometric and optical properties of ZrO 2 and HfO 2 thin films.