Growth of AlN Crystals on SiC Substrates by Thermal Nitridation of Al₂O₃

Abstract

The growth of AlN crystals on c-plane 6H-SiC substrates by thermal nitridation of Al 2 O 3 pellets in the presence of graphite and ZrO 2 was demonstrated. Addition of graphite and ZrO 2 effectively accelerated the evaporation of Al 2 O 3 , yielding c-axis oriented AlN films on SiC substrates. The SiC substrate was severely deteriorated at 2173 K, which produced a porous interface between the AlN film and substrate, resulting in lowquality AlN crystals. The deterioration of SiC was successfully suppressed by introducing a pre-deposited homo-buffer layer, allowing two-dimensional-like growth of AlN. The buffer layer promoted the formation of a high-quality AlN film. At 2173 K, the full-width at half maximum of the X-ray rocking curves of the (0002) and (10-10) planes of the AlN film was 360 and 425 arcsec, respectively.A. Zangvil-contributing editor Manuscript No. 34555.

Conditions for growth of AlN single crystals in Al–Sn flux

“…III‐V nitride semiconductors are widely used in short‐wavelength light‐emitting diodes (LEDs) and laser diodes. AlGaN with a high Al content and AlN are good candidates for deep ultraviolet LEDs and high‐power devices because AlN‐based semiconductors have a wide band gap and high thermal conductivity . To realize these AlN‐based devices, high‐quality and large AlN single‐crystal substrates are required.…”

“…AlGaN with a high Al content and AlN are good candidates for deep ultraviolet LEDs and high-power devices because AlN-based semiconductors have a wide band gap and high thermal conductivity. 1,2 To realize these AlN-based devices, high-quality and large AlN single-crystal substrates are required. AlN single-crystal substrates are typically grown using methods such as sublimation, flux growth, and highpressure growth.…”