A reliable and quick method was reported for detecting threading dislocations in
GaN epitaxial layers grown onto (00•1) sapphire using aqueous KOH etching
maintained at 80C for 10min. Atomic force microscopy characterization of
topological profiles associated with etch-pits revealed asymmetrical and
symmetrical surface topologies. It was argued that high- and low-symmetry
profiles were associated with a and a + c type threading dislocations, whereas
symmetrical profiles were caused by c-type threading dislocations.
Characterization of Threading Dislocations in GaN Using Low-Temperature
Aqueous KOH Etching and Atomic Force Microscopy. I.Han, R.Datta, S.Mahajan,
R.Bertram, E.Lindow, C.Werkhoven, C.Arena: Scripta Materialia, 2008, 59[11],
1171-3