MOCVD of perovskite thin films using an aerosol-assisted liquid delivery system

The deposition of the group II elements Ba and Sr is still the main problem for MOCVD processes of perovskite oxides. In order to overcome the problem of the low vapour pressure of the widely used beta -diketonate precursors, liquid delivery techniques are applied, where the precursors are dissolved in a suitable solvent that can be handled at room temperature before being vaporized. Most of the commercially available liquid delivery systems are based on flash evaporation, that means vaporization occurs in contact with a heated surface, which may result in partial decomposition of the chemicals. We report on an MOCVD system which is based on an aerosol-assisted vaporizer that provides a contact-free evaporation process. This system is characterized by Its simple and robust design and by its versatility, and allows a fast exchange of the precursors. The capability of the system is demonstrated with the examples of SrTiO(3) and (Pb(x)Ba(1-x))TiO(3) thin films. Chemical composition, crystal structure and lattice strain are discussed in detail. Copyright (C) 2000 John Wiley & Sons, Ltd.