Processing and Structural Characterization of Ferroelectric Thin Films Deposited by Ion Beam Sputtering

Abstract

ABSTRACTAn analysis is presented of the ion beam sputter deposition of ferroelectric KNbO3 and Pb(Zr, Ti)O3 (PZT), and the observed compositional, structural, and microstructural properties of these films. Films are deposited using a specially designed computer-controlled system with ability to produce multicomponent films via layer-by-layer deposition of elemental components. Metal or oxide targets are sequentially exposed to a high current ion beam by means of a rotatable target holder. A quartz crystal resonator provides feedback information on layer thicknesses to the computer. Precise control of film stoichiometry is obtained using this method.KNbO3, a material possessing a high figure-of-merit for electrooptic applications, has been deposited epitaxially on (100) MgO substrates. The structure of the optically transparent films has been studied with x-ray and electron diffraction, and transmission electron microscopy. The effects of various processing parameters on the microstructure of the films are discussed.We have demonstrated the ability of the technique to produce multicomponent films and control cation concentration at elevated substrate temperatures for materials such as PZT. The microstructure and associated ferroelectric properties are discussed in relation to processing conditions.