RF-plasma MBE growth of epitaxial metallic TaNx transition metal nitride films on SiC

Abstract

RF-plasma molecular-beam epitaxy was used to epitaxially grow 3–150-nm-thick metallic TaNx thin films on hexagonal SiC substrates. Single-phase hexagonal γ-Ta2N films were obtained when the starting substrate temperature was ∼900 °C and the active N to Ta ratio was ∼2.5–3. The films were characterized using in situ reflection high-energy electron diffraction and ex situ atomic force microscopy, contactless sheet resistance, x-ray diffraction, and cross-sectional transmission electron microscopy. Smooth, single-crystal, low-resistivity films of epitaxial, hexagonal γ-Ta2N on SiC are demonstrated for films at least ∼50-nm-thick.