Spontaneous lateral modulation in short-period superlattices investigated by grazing-incidence x-ray diffraction

摘要: The process of spontaneous lateral composition modulation in short-period InAs-AlAs superlattices has been investigated by grazing-incidence x-ray diffraction. We have developed a theoretical description scattering from laterally modulated structures that makes it possible to determine the lateral directly without assuming any structure model. From experimental intensity distributions in reciprocal space we determined the amplitudes the modulation and its degree periodicity their dependence on number superlattice periods. data follows that cannot be explained by bunching of monolayer steps most likely, is caused stress-driven morphological instabilities growing surface.