Vapour-liquid-solid-like growth of high-quality and uniform 3C-SiC heteroepitaxial films on α-Al2O3(0001) substrates
We demonstrate a heteroepitaxial growth of 3C-SiC thin films on α-Al2O3(0001) substrates by a vapour-liquid-solid (VLS)-like mechanism, an advanced process of alternating deposition of SiC and NiSi2 flux in nanoscale, which process is facilitated by our pulsed laser deposition system with rapid beam deflection (RBD-PLD). In the VLS-like growth, different from conventional VLS processes, the nanoscale liquid precursors diffuse over the substrate and are highly and uniformly dispersed, preventing possible effects on the substrate etching and subsequent film growth by local flux. As a result, the VLS-like growth process is found to work effectively even in heteroepitaxial growth of uniform and high-quality SiC films with a low inclusion of carbon impurity, as evidenced by X-ray diffraction, scanning electron microscopy, Raman spectroscopy and UV-vis spectroscopy. These results illustrate the versatility of the VLS-like growth process for uniform and high-quality crystal thin films of various materials in heteroepitaxial systems.