Pulsed plasma-enhanced chemical vapor deposition of Al 2O 3–TiO 2 nanolaminates

Abstract

Self-limiting synthesis of alumina–titania nanolaminates (ATO, Al 2O 3/TiO 2) was accomplished via pulsed plasma-enhanced chemical vapor deposition. At the synthesis temperature of 150 °C the alumina layers were amorphous, while TiO 2 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 TiO 2 content, though low leakage was restored through interfacial engineering.