Structure and ordering of GaN quantum dot multilayer investigated by 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 quantum dot shape, size and correlation, in both lateral and vertical directions using grazing incidence small angle X-ray scattering. In surface plane, the adjustment of the measurement leads to values for the size and the inter-dot distance that are consistent with direct characterization. In the vertical direction, the correlation length is quantified and shows the perfect vertical alignment of the dots.