Role of ripening and defects in the formation of mesotaxial cobalt-disilicide layers

Previous studies of the formation of buried silicide layers through mesotax y, i.e., the introduction of the metal component by ion implantation with s ubsequent annealing of the structure, have shown that high-quality films ca n be achieved. but at processing temperatures too high to be useful for int egration with silicon device technology. Recently, we proposed a modified r ipening model to describe the early stages of the formation of a buried fil m which intentionally excluded the role of defects. In the current study, t he predictions of that model are tested by varying sample preparation condi tions. We show that the shift of the silicide precipitate layer is correlat ed with the narrowing of the cobalt profile, thus requiring both processes to be described by the same mechanism. We also show in a TEM study that spe cific defect morphologies are correlated with specific properties of the fo rming buried film, requiring an extension of the previous model. (C) 2001 E lsevier Science B.V. All rights reserved.