Seeded growth of AlN bulk single crystals by sublimation

AIN bulk single crystals were grown by sublimation of AIN powder at temperatures of 2110-2300degreesC in an open crucible geometry in a 400 Torr nitrogen atmosphere. Small, single crystalline AIN e-platelets, prepared by vaporization of Al in a nitrogen atmosphere, were used as seeds. Seeded growth occurred preferentially in the crystallographic c-direction, with growth rates exceeding 500mum/h, while the seed crystals grew only marginally in the c-plane. Transparent, centimeter-sized AIN single crystals were grown within 24h. Characterization by X-ray diffraction showed that rocking curves around the (0 0 0 2) reflection were very narrow (25 arcsec full-width at half-maximum), thus indicating very high crystalline quality of the material grown on the seeds. (C) 2002 Elsevier Science B.V. All rights reserved.