Investigation of growth of thin layers of perovskite on native silicon dioxide by a combination of atomic force microscopy and transmission electron microscopy

摘要

Thin layers of (Sr,Ba)TiO_3 perovskite have been grown on native silicon dioxide by pulsed laser deposition at the Technical University of Darmstadt, Germany. Atomic force microscopy (AFM) has been used to investigate the surfaces of the native silicon oxide before and after over-growth by the perovskite in plan-view. Bright-field and dark-field scanning transmission electron microscopy (STEM) in a JEOL 2010F field-emission transmission electron microscope have been combined to investigate the layer stacks of Si/SiO_2/(Ba,Sr)TiO_3 in cross-section. The aim is to correlate surface roughnesses in plan-view geometry with interface roughness in cross-sectional geometry, with an emphasis on detecting percolation in the perovskite layers if they approach thicknesses of only a few unit cells.