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 La1.23Y0.77O3 films are similar to 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 similar to 80:1.