X-RAY REFLECTIVITY INVESTIGATIONS OF THE INTERFACE MORPHOLOGY IN STRAINED SIGE SI MULTILAYERS/

We have studied the lateral and vertical correlation of the interface roughness of Si/SiGe multilayers grown on Si(001) substrates with a mi scut between 0.2 degrees and 0.5 degrees using high resolution x-ray r eflectivity. The theoretical analysis of the measurements proved that the established phenomenological models for the description of the int erface profiles fail in the common case of moderately small miscut ang les. We obtained qualitatively correct results for the roughness corre lations using a microscopic kinetic step-flow growth model, which acco unts for the aggregation of monolayer steps (step bunching) during the hetero-epitaxial growth.