Surface and interface properties of BaTiO3 ferroelectric thin films studied by in-situ photoemission spectroscopy

Overview & Synopsis

The aim of this work was to better understand the surface and interface properties of sputtered ferroelectric BaTiO3 thin films. They are typically used as dielectrics in integrated capacitors, electromechanical sensors and so. This thesis studies the chemical and electronic structures of the interface of BaTiO3 in order to understand basic mechanisms of contact formation with the substrate and the electrode like the Schottky barrier height. Furthermore, the surface stoichiometry of such films has been investigated under different thermal preparation revealing significant instability through segregation phenomenon. Finally, the doping effect with niobium is studied regarding compensation mode, dopant solubility and dielectric properties. The experimental setup allows for in-situ analysis of surface and interface properties using photoelectron spectroscopy.