Nyakiti, Luke OwuorChaudhuri, JharnaKenik, Ed A.Lu, PengEdgar, James H.2009-11-232009-11-232009-11-23http://hdl.handle.net/2097/2183In the present study, the type and densities of defects in AlN crystals grown on 6H-SiC seeds by the sublimation-recombination method were assessed. The positions of the defects in AlN were first identified by defect selective etching (DSE) in molten NaOH-KOH at 400 °C for 2 minutes. Etching produced pits of three different sizes: 1.8, 2.4, and 2.9 μm. The etch pits were either aligned together forming a sub-grain boundary or randomly distributed. The smaller etch pits were either isolated or associated with larger etch pits. After preparing cross-sections of the pits by the focused ion beam (FIB) technique, transmission electron microscopy (TEM) was performed to determine the dislocation type (edge, mixed or screw) associated with a specific etch pit size. Preliminary TEM bright field and dark field imaging using different zone axes and diffraction vectors indicates an edge dislocation with a Burgers vector 1/3[1120] is associated with the smallest etch pit size.This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).Article (publisher version)