Self-Assembled SiGe Dots

摘要

We review recent progress in the growth and characterization of Si_(1-x)Ge_x islands and Ge dots on (001) Si. We discuss the evolution of the island morphology with Si_(1-x)Ge_x coverage, and the effect of growth parameters or post-growth annealing on the shape of the islands and dots. We outline some of the structural, and optical properties of Si_(1-x)Ge_x islands and review recent progress in the determination of their composition and strain distribution. We describe the use of undulated Si_(1-x)Ge_x islands superlattices for infrared detection at telecommunication wavelengths. We discuss various approaches currently being investigated to engineer Si_(1-x)Ge_x quantum dots and in particular control their size, density and spatial distribution. For example, we show how C pre-deposition on Si (001) can influence nucleation and growth of Ge islands. We also show how low temperature Si homoepitaxy can lead to a particular surface cusp morphology that may promote dot nucleation.