Free nucleation of aluminum nitride single crystals in HPBN crucible by sublimation

摘要

Clear and colorless aluminum nitride (AIN) single crystal thin platelets up to 60mm(2) were prepared at 2100degreesC and 800Torr in hot-pressed boron nitride (HPBN) crucibles by free nucleation in a graphite furnace. Crystals grown in HPBN crucibles typically form thin platelets with the fastest growth rate (above 400 mum/h) occurring in the c-axis direction. Growth striations frequently run the length of the crystals, probably due to the presence of boron in the growth environment. Raman spectra and X-ray topography reveal that the crystals have good structural quality. Emissions peaks around 4.10 eV, 3.90 eV, and 3.70 eV were observed in the photoluminescence spectrum, suggesting that boron from the boron nitride crucible may incorporate into the AIN crystals as hexagonal boron nitride. (C) 2004 Elsevier B.V. All rights reserved.