Detection and measurement of local distortions in a semiconductor layered structure by convergent-beam electron diffraction.

It is shown that local tetragonal distortion in a Si Ge0.05Si0.95 strained-layered structure can be detected and quantified from analyses of the high-order Laue zone lines which are present in the bright-field disks of [001] convergent-beam electron diffraction patterns. The detection of a tetragonal distortion is based on symmetry arguments, whereas the quantification requires a detailed analysis which is based on computer simulated patterns, assuming a kinematical approximation of the scattering process and including surface relaxation. The result of this quantitative analysis is in good agreement with the tetragonal distortion which is predicted by isotropic elasticity theory. [ABSTRACT FROM AUTHOR]