Silicide interfaces in silicon technology

Abstract

This paper does not constitute an overall review of the role of interfaces in the use of silicides in current microelectronic technology. However, for the sake of some degree of completeness, most of the uses of silicides, be it infrared detection or thermoelectric generation, are mentioned and some recent references listed. Emphasis is given to four different topics. The first is the use of PtSi for ohmic and rectifying contacts; this provides the opportunity a) to look at the development of planar device metallization, starting with aluminum, and b) to survey briefly elements of the theory of Schottky and ohmic contacts to semiconductors. A second topic is the epitaxy of silicides on silicon, with a brief discussion of β-FeSi2, recently shown to be electroluminescent. What is known about grain boundary diffusion in silicides and other intermetallic compounds is reviewed with some speculation about the structure of grain boundaries and the consequences for silicide growth via solid state reactions. Finally, the role of epitaxy between various morphological variations of TiSi2 is examined because of the important place of this silicide in metal oxide semiconductor field effect transistor technology.