Local strain distributions in silicon-on-insulator/stressor-film composites

We have used scanning microdiffraction topography to determine the mismatch strains and local strain distributions in silicon-on-insulator substrates with overlying thin film stressor features. Analysis of the data using the edge-force model and the Ewald-von Laue dynamical diffraction theory shows the presence of an exponential strain gradient in the vicinity of the buried SiO2 /Si -substrate interface. We show that, for simple geometries, it is possible to deduce the sign of the mismatch strain simply by inspecting the microdiffraction topograph. © 2008 American Institute of Physics.