Columnar growth structure and evolution of wavy interface morphology in amorphous multilayered thin films

Columnar growth and evolution of wavy interface morphology, formation of nodes and growth morphology on a random surface was investigated by cross-sectional transmission electron microscopy (XTEM) in sputtered amorphous Si/Ge (a-Si/Ge) multilayers. It was demonstrated that shadowing is responsible for the formation of these morphological features and Huygens principle can be applied for their description. For the study of the relation of the columnar growth and wavy interface morphology periodic multilayers were deposited with layer thicknesses up to 50 nm. In a-Si/Ge multilayers the minima of the wavy interface morphology, coincide with the column boundaries. The diameter of columns shows linear dependence on the thickness of the thicker component layer, indicating that the correlated multilayer structure is established by the surface morphology of the thicker component layer. (C) 1999 Elsevier Science S.A. All rights reserved.