Chapter 6 - Strained-layer heteroepitaxy to fabricate self-assembled semiconductor islands

Abstract

This chapter discusses types of self-assembled quantum structures that involve the formation of defect-free three-dimensional islands during strained-layer epitaxy. Because the formation of these island nanostructures is highly dependent on the growth process, the basics of heteroepitaxy has been reviewed. The common experimental techniques used to fabricate and study these structures have also been discussed along with properties and applications of these islands. Self-assembled islands formed during strained-layer epitaxy constitute a unique and promising approach to the fabrication of semiconductor nanostructures. During growth, the deposited material grows in a two-dimensional fashion until a transformation occurs and three-dimensional growth begins. The two-dimensional islands that grow during the early stages are often anisotropic and depend on the nature of the deposition surface. The transition is abrupt and the resulting islands are uniform in size. These islands have special properties and are being used more frequently for physical studies and device fabrication. Thermodynamic issues such as elastic strain and kinetic issues such as surface diffusion are part of the complex process of self-assembled island formation.