Structure and ordering of GaN quantum dot multilayers

Grazing incidence x-ray techniques are used to characterize the structure o f multilayered GaN quantum dots in an AlN matrix. For a dot lateral size of 170 Angstrom, the values of the interdot vertical and lateral correlation lengths are 1500 and 250 Angstrom, respectively. The presence of smaller qu antum dots is observed only in the layers deposited first. The strain distr ibution in the multilayer is also investigated as a function of depth. Alon g the dot columns, the crystal lattice remains coherent, with elastic relax ation from the bottom to the top of the multilayer. (C) 2001 American Insti tute of Physics.