Molecular Beam Epitaxy Grown Template For Subsequent Atomic Layer Deposition Of High Kappa Dielectrics

Molecular beam epitaxy (MBE) grown high kappa dielectrics of Al2O3 and HfO2 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 Al2O3(1.9 nm)/MBE Al2O3(1.4 nm) and ALD Al2O3(3.0 nm)/MBE HfO2(2.0 nm) showed overall kappa values of 9.1 and 11.5, equivalent oxide thicknesses of 1.41 and 1.7 nm, D-it of 2.2x10(11) and 2x10(11) cm(-2) eV(-1), and leakage current densities of 2.4x10(-2) A/cm(2) at V-fb-1 V and 1.1x10(-4) A/cm(2) at V-fb+1 V, respectively. The attainment of high dielectric constant suggests that there is no low kappa capacitor in series near the oxide/Si interface.