Influence of grown conditions on dodecagonal GaN micro-pillars structural parameters investigated by XRD

In this paper, we present results of x-ray diffraction investigations of GaN micro-pillars grown on GaN template. These rods are special in so far that they have stable a- and m-plane side walls and dodecagonal and not hexagonal shape as usual. Such growth mode is simulated by adding As as surfactant. The work shows the influence of changing the amount of gallium and arsenic and lowering the temperature on the growth of micro-pillars. Changing the growth parameters led to both a change in the density of the growing micro-pillars, their height and width, and their structural parameters, such as a disturbance in the direction of growth of the structures. In order to characterize the studied samples, measurements were carried on the configuration from the surface and from the edge of the sample. This measurements method allowed to visualize the structure in the perpendicular and parallel directions of the micro-pillars growth. In addition, the strain and mosaic analysis showed correlations between the resulting shape and density of the rods and the strain of the GaN-pillar and GaNAs crystalline lattice.