X-ray reflection from self-organized interfaces in an SiGe/Si multilayer

Interface morphology of a strained SiGe/Si multilayer has been investigated by means of non-specular x-ray reflection. Depending on the azimuth of the scattering plane, two types of interface pattern have been observed, namely an asymmetrical random staircase and symmetrical islands superimposed on it. The distribution of the scattered intensity in reciprocal space has been simulated using a structure model of self-similar interface patterns and the distorted-wave Born approximation. The parameters of the interfaces following from the fit of the measured and simulated data were compared with the results of high-resolution x-ray diffractometry and transmission electron microscopy, and a good correspondence has been achieved.