Metal alkoxides and β‐diketonates as precursors for oxide and non‐oxide thin films

Abstract

AbstractSingle‐components or multicomponent oxide thin films are of interest for electronic and opto‐electronic devices, optical applications, catalysis, corrosion protection etc. Their preparation by chemical routes is based on the hydrolytic (sol‐gel process) or pyrolytic (MOCVD) conversion of precursors. Derivatives having MO bonds, namely metal alkoxides, carboxylates or β‐diketonates, are the most common sources of metal oxides. The properties of alkoxides are appropriate for sol‐gel as well as MOCVD applications, whilst the limited hydrolytic susceptibility but good volatility of β‐diketonates is most convenient for MOCVD purposes. The low temperature and flexibility of sol‐gel routes, and the presence of residual OH groups in the final films, are favorable for the encapsulation of organic or organometallic derivatives, the anchoring of enzymes and in general for the development of functional and composite coatings. The facile formation of heterometallic alkoxides is also attractive for the development of coatings based on multimetallic formulations. MOCVD is favorable for the buildup of heterostructures and epitaxial layers. Although metal alkoxides and β‐diketonates are usually oxide precursors, nitride or sulfide films can be obtained by reacting with the appropriate reagents. Fluorinated ligands enhance volatility but often result in the formation of metal fluorides.