Selected-area electron-channeling pattern as a characterization method for heteroepitaxial layers

Strongly mismatched III/V-compound semiconductor heteroepitaxial layers on Si were investigated with respect to their crystal quality by quantitative analysis of selected-area electron-channeling patterns (SAECP). An algorithm, based on the statistical analysis of 2-D SAECPs using digital image processing, is described. Agreement is found between the crystal quality of the thin nucleation layers obtained by SAECP and the density of structural defects as determined by spectroscopic ellipsometry. Furthermore, an area-selectively thinned InP/Si sample was examined by SAECP to obtain the dislocation density versus the residual layer thickness. The dislocation-density distribution agrees well with the theoretical prediction and experimental reference data.