Structural characterization of epitaxial γ-Ta2N thin films and AlN/γ-Ta2N heterostructures on SiC substrates

Tantalum nitride (gamma-Ta2N) thin films were grown by radiofrequency plasma molecular beam epitaxy (MBE) on 3 in. diameter 6H- or 4H-SiC substrates. Epitaxial characteristics of these MBE grown layers were determined using high resolution x-ray diffraction (HRXRD) and transmission electron microscopy (TEM) measurements. HRXRD, TEM, and XRD reciprocal space map measurements show that.-Ta2N on SiC grows pseudomorphically and stabilizes to a nearly pure gamma-Ta2N phase. Structural properties of these layers are uniform across the 3 in. wafer diameter. Measured a and c lattice parameter values of a 43 nm thick gamma-Ta2N film on 6H-SiC are 3.079 and 4.898 angstrom, respectively, and the film has an in-plane tensile strain of 1.03%. MBE growth of AlN/gamma-Ta2N /SiC heterostructures has also been demonstrated. Measured lattice a and c constants of AlN on.gamma-Ta2N /SiC are 3.120 and 4.974 angstrom, respectively. TEM and XRD show that SiC substrate and gamma-Ta2N films have parallel epitaxial relation.

Automated summary

Tantalum nitride (γ-Ta2N) thin films were grown on 3 in. diameter 6H- or 4H-SiC substrates by radiofrequency plasma molecular beam epitaxy (MBE). The MBE grown layers showed epitaxial characteristics and nearly pure γ-Ta2N phase. The lattice parameters and strain of the films on SiC were measured. Additionally, the MBE growth of AlN/γ-Ta2N /SiC heterostructures was demonstrated.