The influence of GaN/AlN quantum dots on crystalline quality of AlN grown on

multistacked quantum dot layers was studied as a function of the GaN deposition.

Dislocations in the AlN grown on the quantum dot quantum dot layers were bent

by the existence of the quantum dot layers and the dislocation density in the AlN

was one order of magnitude smaller than that in AlN grown on sapphire substrate.

In the measurement of Raman spectra, AlN E2 frequency and GaN A1 frequency

depended on the deposition of GaN. The dependence of these two frequencies was

strongly correlated. This suggested that the crystalline quality of AlN was affected

by the growth condition of the GaN quantum dots and size distribution of quantum

dots was of great importance in reduction of the dislocation density in AlN by

using the quantum dot layers as a buffer layer. The reduction of dislocation in the

AlN was efficient when the small quantum dots were grown uniformly but

inefficient when the large quantum dots were grown. Dislocation Density in AlN Grown on Multistacked GaN/AlN Quantum Dot Layers

by Molecular Beam Epitaxy. N.Managaki, N.Iizuka: Physica Status Solidi C, 2009,

6[S2], S531-4