Chapter 12 Intrinsic stress of epitaxial thin films and surface layers

Abstract

This chapter discusses intrinsic stress of epitaxial thin films and surface layers. Future application of thin films in nanoscale technology substantially tightens the demands on stability as well as on structural and compositional integrity and ultimately necessitates the fabrication of high quality single crystalline films. A preparation technique in the past that has proven its capability to meet high standards was molecular beam epitaxy (MBE). Epitaxial films and surface layers that are arranged coherently with a mismatched support—for example, the substrate or bulk crystal, respectively, are elastically strained, and therefore are in a state of stress. In the literature, two complementary approaches can be found to investigate the response to misfit: (1) techniques, which determine the strain by measuring interatomic distances and (2) techniques, which determine the stress from the bending of the support. Recently, scanning tunneling microscopy (STM) has also contributed successfully to the investigation of the transmittance of misfit strain during epitaxial growth.