Faceting in AlN bulk crystal growth and its impact on optical properties of the crystals

• DOI: 10.1002/pssc.201100345
• Publication Date: 2012-01-13T13:37:00Z
• Authors: Matthias Bickermann; Boris M. Epelbaum; Octavian Filip; Barbara Tautz; Paul Heimann; Albrecht Winnacker
• Keywords: Faceting; Cathodoluminescence; Facet (psychology); Crystal (programming language); Basal plane

Abstract The surface of bulk AlN single crystals grown by PVT on Al‐polar (0001) seeds is typically constructed from prismatic, pyramidal, and basal plane facets. Simultaneous growth different facets with kinetics leads to formation a zonar structure which visible due local differences in coloration the wafers. Four zones an wafer representing (1) {10 1 3} pyramidal facets, (2) adjacent ridges (3) + (4) outer centre areas corresponding depressions are investigated. They show striking optical absorption (OA) spectra, cathodoluminescence (CL) spectra chemical analysis (SIMS). In near centres depressions, deep‐UV as well luminescence significantly increased. We assign OA CL bands observed these presence carbon and/or lack oxygen segregation effects caused faceting. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)