Simultaneous analysis of multiple extended x-ray-absorption fine-structure spectra: Application to studies of buried Ge-Si interfaces

Ge K-edge extended x-ray-absorption fine-structure (EXAFS) spectra of a series of strained-layer [(Si)m/(Ge)n]p superlattices grown by molecular-beam epitaxy on the 〈100〉 face of single-crystal Si have provided a determination of the degree of intermixing and the extent of relaxation as a function of the thickness of the Ge layer. The results are obtained with use of constrained simultaneous nonlinear least-squares curve fits to multiple data …