Investigation of Strain and Thin Film Relaxation in GexSi1-x/Si Strained-Layer Superlattice by Dark-Field Electron Holography

Elastic strain plays an important role in modifying physical properties such as the mobility of charge carriers in semiconductors. Strain analyses reveal that the reduction of the total strain and the elastic strain could be as large as 30 and 65%, respectively in a very thin transmission electron microscopy (TEM) specimen. The strain and thin film relaxation in a cross-sectional transmission electron microscopy (XTEM) specimen of GeSi/Si strained-layer superlattice has been investigated by dark-field electron holography with a large holographic field of view (FOV) to 150 nm achieved by moving the specimen down below the front-focal plane of the objective lens in free lens control mode. [doi:10.2320/matertrans.M2012138]