Characterization of Interface Roughness

Abstract

In this chapter, the characterization of interface roughness is discussed. Roughness can be often described by a self-affine model of the height profile. This holds even in the case of very flat stepped interfaces of semiconductor layer systems grown on vicinal substrates. However, the existence of atomic steps and step bunches induces anisotropic interface morphologies and inclined inheritance of interface roughness in a multilayer. How these effects can be analyzed will be discussed in detail. In particular, a simple geometric model is presented which simplifies the evaluation of inclined interface roughness. We shall also demonstrate that with increasing strain, the model of self-affine roughness will break down, and monodisperse step bunches show up that may partially release their internal strain.