High temperature HVPE of AlN on sapphire templates

Abstract Aluminum nitride (AlN) was grown on c‐plane sapphire substrates by hydride vapor phase epitaxy (HVPE). The experiments utilized a two zone inductively heated hot‐wall reactor capable of temperatures exceeding 1500 °C. The precursors of aluminum monochloride (AlCl) and aluminum trichloride (AlCl 3 ) were used, and it was determined that AlCl 3 was more thermodynamically conducive to single crystalline AlN growth at 1450 °C. AlN templates were optimized at a thickness of 1 µm without cracking. The double axis X‐ray diffraction (XRD) rocking curves full width half maximums (FWHMs) were reproducibly demonstrated with an average of 130 arcsec for the (002) and 516 arcsec for the (102). The AlN was transparent in the UV spectrum with a band gap cut off of 200 nm. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)