Molecular beam epitaxy grown template for subsequent atomic layer deposition of high κ dielectrics.

Molecular beam epitaxy (MBE) grown high κ 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 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. [ABSTRACT FROM AUTHOR]