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HfTiO2 layers of various stoichiometries where deposited by physical vapor depostion on TiN and TiN/Ru bottom electrodes (BE) in order to determine the influence of composition, conduction band offset, and BE morphology on the overall leakage current characteristics. Current-voltage spectroscopy, transmission electron microscopy, electron energy loss spectroscopy, and conductive atomic force microscopy studies show increased leakage current and charge trapping with increased Ti content. The interplay of conduction band offset and trap density were studied. The influence of Ru bottom electrode roughness on the leakage current is higher than the influence of Ti content and low conduction band offset. [ABSTRACT FROM AUTHOR]

The charge transport in (Zr02)0.8(Al2O3)0.2 thin films consisting of nanoscale crystallites in an amorphous matrix were investigated by conductive atomic force microscopy. Local current-voltage curves were obtained either from multiple current images for different biases or by ramping the tip bias at a specific location. Comparison of both approaches for amorphous matrix sites implies that they are equivalent. Current-voltage curves for crystallite and amorphous sites are different, but repeated voltage ramps at amorphous sites yield curves as obtained at pristine crystallites. This suggests charge transport through leakage paths along defects at grain boundaries and along stress-induced defects at amorphous sites. [ABSTRACT FROM AUTHOR]