Atomic layer deposition of lanthanum-based ternary oxides

Abstract

Lanthanum-based ternary oxide LaxM2-xO3 (M = Sc, Lu, or Y) films were deposited on HF-last Si substrates by atomic layer deposition. Both LaScO3 and LaLuO3 films are amorphous while the as-deposited LaxY2-xO3 films form a polycrystalline layer/amorphous layer structure on Si. Transmission electron microscopy and electrical analysis show the absence of interfacial layers. The dielectric constants for LaScO3, LaLuO3, and La 1.23Y0.77O3 films are ∼23, 28 ± 1, and 17 ± 1.3, respectively, with leakage current density up to 6 orders of magnitude lower than that of thermal SiO2 with the same effective oxide thickness. Conformal coating thickness is demonstrated on holes with aspect ratio ∼80:1. © 2009 The Electrochemical Society.