Growth of AlN single crystals on 6H‐SiC (0001) substrates with AlN MOCVD buffer layer

Abstract

Abstract6H‐SiC (0001) deposited 300 nm thick AlN film by MOCVD was used as the substrate to grow AlN crystals by the physical vapour transport (PVT) method. It was confirmed that c‐axis oriented AlN films were grown and this material had a 3D growth mode. The root mean square (RMS) value for the film was measured to be 2.17 nm. Nucleation and further growth of AlN on so prepared substrate was investigated. Colorless and transparent AlN crystal with 1 mm thick and 40 mm in diameter was obtained after 4 h growth on this substrate. The transparent AlN showed strong (0001) texture XRD patterns, only the (0002) reflection was observed in symmetric θ‐2θ scans. The full width at half maximum for a (0002) X‐ray rocking curve was less than 0.1° indicating good crystalline quality. Anisotropic etchings in molten KOH shows that the growth (0001) plane exposed to the AlN source predominately has an aluminum polarity, no N‐polar inversion domains were observed. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Debye temperature of wurtzite AlN determined by X-ray powder diffraction

“…AlN polycrystalline wafer was selected as seed. Experimental details can be found elsewhere (Zuo et al , 2012). Pre-sintered source was held into a TaC crucible, which was encased by a graphite crucible.…”

Ultraviolet emission from high-quality crystalline ultra-long AlN whiskers

“…The source was first placed into the TaC crucible loaded in a graphite crucible, then the graphite crucible was placed inside the induction heating furnace. A sketch of the experimental configuration of the crucible and growth assembly was illustrated by Zuo et al (2012). AlN whiskers were grown in a temperature of 1800 °C, under a nitrogen (99.99%) pressure of 0.6 atm and a distance of 15 mm between the source and crucible lid.…”

Observation of the Long Afterglow in AlN Helices

“…AlN has recently been the subject of intense research efforts due to its superior physical properties such as ultrawide direct bandgap, high melting point, and high thermal conductivity. These properties make it suitable as the ultimate material for the fabrication of laser diodes (LDs), photodetectors, and the deep-ultraviolet light-emitting diodes (DUV-LEDs) over the past several decades. − However, growth of AlN with high optical and structural quality as well as a high purity is very essential for the high performance of AlN-based optoelectronic devices. Therefore, it is highly desirable to understand the intrinsic features of native point defects including vacancy, antisite, interstitial, and their complexes because these defects have significant influence on the charge carrier density and dynamics in AlN. − It is very important to shed light on this, both for a fundamental understanding as well as for their practical applications.…”