Extracting composition and alloying information of coherent Ge(Si)/Si(001) islands from [001] on-zone bright-field diffraction contrast images

Abstract

Ge(Si)/Si(001) coherent islands grown at 700 °C by molecular beam epitaxy were investigated using transmission electron microscopy. [001] on-zone bright-field diffraction contrast imaging and image simulation techniques were used to investigate the structure of these coherent islands. Comparison of simulated and experimental images indicates nonuniform composition distribution within the coherent islands when the islands were grown at high temperatures (700 °C), but uniform composition for growth at lower temperatures (600 °C).