Sublimation growth of non-polar AlN single crystals was investigated. The crystals were prepared in two methods: By slicing along the m-plane from c-plane-grown thick crystals, and by hetero-epitaxial growth on m -plane SiC substrates. Defects of the crystals were observed by high-resolution transmission electron microscope. The dislocation density in AlN/SiC (00•1) decreased significantly at about 1.5μm above the interface, while stacking faults initiated from the interface toward the growth surface in AlN/SiC (1¯1•0). With increasing crystal thickness, the dislocation density decreases up to 5 x 104/cm2 at a thickness of 10mm. In the AlN single crystal grown on SiC (00•1), it was noteworthy that the dislocations were localized around the AlN/SiC interface and that far fewer dislocations occurred near the growth surface. High-crystallinity AlN thick single crystals could be grown on SiC (00•1) substrates.

Sublimation Growth of Nonpolar AlN Single Crystals and Defect Characterization. I.Satoh, S.Arakawa, K.Tanizaki, M.Miyanaga, Y.Yamamoto: Physica Status Solidi C, 2010, 7[7-8], 1767–9