Abstract
Understandings and control of solid-phase reaction at metal/Si interfaces become more and more important in realizing future ULSI devices. In this paper, we have summarized the general formation process of silicide at metal/Si interfaces and discussed the interfacial reaction in Co/Si (001) and Ti/SiGe/Si (001) systems from a viewpoint of ULSI applications. In the case of epitaxial growth of thin CoSi2 films, surface morphology is strongly affected by defects and adsorbed-oxygen atoms on Si surfaces, which means that the control of Si surfaces is essential to grow high-quality epitaxial CoSi2 films. At the Ti/SiGe interfaces, Ti atoms preferentially react with Ge atoms and Ge-rich SiGe layers are formed as a result of solid-phase reaction. It can be concluded that SiGe/Si heterostructures are one of candidates in realizing low resistivity contacts.
