Atomic Layer Deposition of Lanthanum-Based Ternary Oxides

Lanthanum-based ternary oxide \(La_xM_{2−x}O_3\) (M = Sc, Lu, or Y) films were deposited on HF-last Si substrates by atomic layer deposition. Both \(LaScO_3\) and \(LaLuO_3\) films are amorphous while the as-deposited \(La_xY_{2−x}O_3\) 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 \(LaScO_3\), \(LaLuO_3\), and \(La_{1.23}Y_{0.77}O_3\) films are \(\sim 23\), \(28 \pm 1\), and \(17 \pm 1.3\), respectively, with leakage current density up to 6 orders of magnitude lower than that of thermal \(SiO_2\) with the same effective oxide thickness. Conformal coating thickness is demonstrated on holes with aspect ratio \(\sim 80:1\).