Pulsed plasma-enhanced chemical vapor deposition of Al2O3-TiO2 nanolaminates

Self-limiting synthesis of alumina-titania nanolaminates (ATO, Al2O3/TiO2) was accomplished via pulsed plasma-enhanced chemical vapor deposition. At the synthesis temperature of 150 degrees C the alumina layers were amorphous. while TiO2 layers displayed a polycrystalline anatase structure. Digital control over nanolaminate structure was demonstrated through elemental analysis and transmission electron microscopy imaging. The dielectric performance of the ATO structures was examined as a function of composition and bilayer thickness. Capacitance-voltage measurements showed that the effective dielectric constant was consistent with treating the nanolaminates as individual capacitors in series. Current-voltage measurements showed that leakage current deteriorated with TiO2 content, though low leakage was restored through interfacial engineering. (C) 2009 Elsevier B.V. All rights reserved.