Recently, gallium nitride (GaN) films grown on graphene have been widely studied. Here, we have grown low-threading-dislocation-density GaN films on graphene by hydride vapor phase epitaxy (HVPE). The full widths at half maximum (FWHMs) of X-ray rocking curves (XRCs) of the GaN films were 276 and 350 arcsec at the 0002 and reflections, respectively. This shows that the threading dislocation densities are on the order of magnitude of 108 cm−2, which is consistent with the results of cathodoluminescence (CL).
Growth of high-quality GaN within a limited thickness is still a challenge, which is important both in improving device performance and in reducing the cost. In this work, a self-organized graphene is investigated as a nano-mask for two-step GaN epitaxial lateral overgrowth (2S-ELOG) in hydride vapor phase epitaxy. Efficient improvement of crystal quality was revealed by x-ray diffraction. The microstructural properties, especially the evolution of threading dislocations (TDs), were investigated by scanning electron microscopy and transmission electron microscopy. Stacking faults blocked the propagation of TDs, and fewer new TDs were subsequently generated by the coalescence of different orientational domains and lateral-overgrown GaN. This evolution mechanism of TDs was different from that of traditional ELOG technology or one-step ELOG (1S-ELOG) technology using a two-dimensional (2D) material as a mask.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.