A Model System: LPE SiGe/Si(001) Islands

Abstract

This section deals with an ideal model system of i_{1-x}Ge_x islands grown by liquid-phase epitaxy (LPE). These islands are too large to show quantum size effects. However, they are grown rather close to thermodynamic equilibrium and are very regular in shape, size, and chemical composition. Therefore, LPE-grown islands may serve as a model system with regard to a better understanding of the Stranski--Krastanow growth mode. Consequently, we shall first focus on the basic aspects of growth. Beyond the growth aspect, LPE-grown SiGe islands also represent a model system for X-ray diffuse scattering. They are large enough to give sufficiently high scattering signals. On the other hand, the very regular shape and size can be exploited to determine growth-induced composition gradients inside the islands. Besides that, positional correlation effects can be studied and a rich variety of details can be revealed.