Investigation of GaN quantum dot stacking in multilayers with X-ray grazing incidence techniques

The growth of GaN quantum dot multilayers embedded in an AlN matrix can be controlled using the Stranski–Krastanov mode. For samples grown in the wurtzite structure, we present a non-destructive statistical investigation of the structure and ordering of the GaN quantum dots, using X-ray grazing incidence techniques. With grazing incidence small-angle X-ray scattering we can quantify the strong vertical alignment of the dots. With grazing incidence diffraction, the strain in the multilayer is analyzed. We find that the GaN quantum dots are partially relaxed to a lattice parameter between the bulk value for GaN and that of the AlN lattice.