Iron(III) β-diketonates: CVD precursors for iron oxide film formation

Abstract Complexes [Fe(β-diketonate) 3 ] (β-diketonate = 2-acetylcyclopentanoate ( 3a ), = 2-acetylcyclohexanoate ( 3b ), = 4,4-dimethyl-1-phenyl pentanedionate ( 3c )) were synthesized by the reaction of FeCl 3 with the respective β-diketones in presence of NaOH. The molecular structures of 3a and 3c in the solid state are discussed, confirming an octahedral coordination sphere at Fe(III) setup by the three bidentate-bonded β-diketonato ligands. Variation of the β-diketonato ligands allowed to influence the thermal behavior and vapor pressure of the complexes. TG-MS ( = Thermo Gravimetry-Mass Spectrometry) studies, exemplarily carried out on 3a , confirmed the release of the β-diketonate ligands. Complexes 3a – c were applied as MOCVD (=Metal-Organic Chemical Vapor Deposition) precursors for the deposition of Fe 2 O 3 thin films on silicon substrates. It was found that with 3a , b , conformal and dense carbon-free γ- and α-Fe 2 O 3 layers were produced at 450 °C, which was verified by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photon spectroscopy.