The interface analysis of GaN grown on 0° off 6H-SiC with an ultra-thin buffer layer

Abstract

Previously, we reported a growth method by metalorganic vapor phase epitaxy using a single two-dimensional growth step, resulting in 1.2-µm crack-free GaN directly grown on 6H-SiC substrate. The introduction of Al-treatment prior to the standard GaN growth step resulted in improved surface wetting of gallium on the SiC substrate. Transmission electron microscope and energy dispersive spectrometer analysis of the epitaxial interface to the SiC determined that an ultra-thin AlGaN interlayer had formed measuring around 2–3 nm. We expect our growth technique can be applied to the fabrication of GaN/SiC high frequency and high power devices.