Abstract
Molecular beam epitaxy (MBE) grown high κ dielectrics of Al2 O3 and Hf O2 are employed as templates to suppress effectively the oxide/Si interfacial layer formation during the subsequent atomic layer deposition (ALD) growth. The absence of the interfacial layer was confirmed using x-ray photoelectron spectroscopy and high resolution transmission electron microscopy. Two composite films consisting of ALD Al2 O3 (1.9 nm) MBE Al2 O3 (1.4 nm) and ALD Al2 O3 (3.0 nm) MBE Hf O2 (2.0 nm) showed overall κ values of 9.1 and 11.5, equivalent oxide thicknesses of 1.41 and 1.7 nm, Dit of 2.2× 1011 and 2× 1011 cm-2 eV-1, and leakage current densities of 2.4× 10-2 A cm2 at Vfb -1 V and 1.1× 10-4 A cm2 at Vfb +1 V, respectively. The attainment of high dielectric constant suggests that there is no low κ capacitor in series near the oxide/Si interface. © 2006 American Institute of Physics.