Abstract
The quantitative study by transmission electron microscopy (TEM) of crystalline defects in ultra-thin film deposited on a substrate system is often complicated by the elastic interactions between short dislocation segments and the free surface of the film. It is shown, in the frame of isotropic elasticity and two-beam dark-field TEM, how to tackle the quantitative identification of short inclined segments of misfit dislocations located at a few tens of nanometers below a free surface. The method, which uses repeatedly the concept of angular dislocation, is applied to some defects observed in a GeSi film deposited on a surface slightly deviating from a (0 0 1) silicon surface. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim