Polymer-assisted deposition of metal-oxide films

In the last several years, metal-oxides have become the basis for many revolutionary electronic devices because they exhibit a wide range of electronic properties that conventional metallic elements and covalent semiconductors do not possess. Metal-oxide films can be grown by physical vapor deposition, chemical vapor deposition, and chemical solution deposition techniques. One of the challenges in solution-based processes of complex functional metal-oxide films has been to produce high quality films and at the same time to control the stoichiometry. In this talk, we describe a new chemical solution method called polymer-assisted deposition (PAD) to grow epitaxial complex metal-oxides such as ferroelectric Ba1-xSrxTiO3, Pb0.40Sr0.60TiO3, and BaZr0.27Ti0.73O3 films. We use a new strategy to control the distribution of metals in solution at a molecular level and a mixture of metal precursor and soluble polymer to form a solution with desired viscosity. By actively binding the metal, the polymer serves to encapsulate the metal to prevent chemical reaction while maintaining an even distribution of the metal in solution.?? This ensures a homogeneous metal distribution and prevents unwanted reactivity that can lead to the formation of undesired phases. The successful growth of epitaxial ferroelectric films with desired properties by PAD suggests that PAD is a feasible alternative approach to the growth of high quality ferroelectric materials.