Ostwald ripening in two-dimensional and three-dimensional systems of As clusters in low temperature grown GaAs films

Two-dimensional (2D) sheets of As clusters were produced in the crystalline GaAs matrix using molecular-beam epitaxy (MBE) at low temperature, indium delta-doping, and subsequent annealing. The sheets were inserted into a 3D array of arsenic clusters. Ostwald ripening in 2D and 3D cluster systems was studied using cross-sectional transmission electron microscopy. The cluster growth rate was found to be lower in the 2D system, than in the 3D one. The thickness of the 2D sheets increased with cluster coarsening and was evaluated as double average cluster diameter. The limitations were found for design of structures with built-in 2D sheets of As clusters separated by cluster-free GaAs matrix.