Nanoscale leakage current measurements in metal organic chemical vapor deposition crystalline SrTiO3 films

The properties of SrTiO3 thin films, grown by liquid injection metal organic chemical vapor deposition on Si/SiO2, using a mixture of precursors, have been investigated at the nanoscale using an Atomic Force Microscope in the so-called Conductive Atomic Force Microscopy mode. Maps of the leakage currents with a nanometric resolution have been obtained on films elaborated at different temperatures and stoichiometries in order to discriminate the role of each parameter on the onset of leakage Currents in the resulting layers. it appears that the higher the deposition temperature, the higher the leakage currents of the films. The mapping with a nanometric precision allows to show a heterogeneous behaviour of the surface with leaky grains and insulating boundaries. The study of films elaborated at the same temperature with different compositions supports the assumption that the leakage currents on Ti-rich layers are far higher than on Sr-rich layers. (C) 2008 Elsevier B.V. All rights reserved.