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 dia gram: two-dimensional (2D)-growth, 'hut'- and 'dome'-clusters, 'dome'-clust ers with misfit dislocations at the interface. Variations in the lattice co nstants 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 at tributed to the elastic deformation at the stage of 2D growth and formation of 'hut'-clusters and to the plastic relaxation for the 'dome'-clusters. A s 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 tota l electron structure of the hole spectrum of Ge quantum dots in Si was esta blished. (C) 2000 Elsevier Science B.V. All rights reserved.