In situ RHEED control of self-organized Ge quantum dots

In situ registration of high-energy electron diffraction patterns was used for constructing the diagram of structural and morphological states of the Gz film on the Si(100) surface. The following regions identified in the diagram: two-dimensional (2D)-growth, 'hut'- and 'dome'-clusters, 'dome'-clusters with misfit dislocations at the interface. Variations in the lattice constants of the Ge film during, the MBE growth on the: Si(100) surface were determined. An increase in the lattice constant at the (100) surface was attributed to the elastic deformation at the stage of 2D growth and formation of 'hut'-clusters and to the plastic relaxation for the 'dome'-clusters. As a result, epitaxial silicon structures with germanium quantum dots of 15 nm base size at the density of 3 x 10(11) cm(-2) were synthesized. The total electron structure of the hole spectrum of Ge quantum dots in Si was established. (C) 2000 Elsevier Science B.V. All rights reserved.