Electronic states and microstructure at the silicide-silicon interface

The understanding of Schottky barrier formation at the silicide-silicon contact requires information on the electronic states and microstructure of the reacted interface. Considerable progress has been made recently in the study of these interface properties using surface spectroscopy, transmission electron microscopy and ion channeling techniques. This review is focused mainly on the results for the near-noble metal silicides with some brief discussions for the refractory metal silicides. The basic bonding characteristics in silicides are discussed first with emphasis on the role of hybrid states between metal d and Si p orbitals. Then the stoichiometry and microstructure of the interface as well as their effect on the electronic properties are described. Spectroscopy evidence is given to show the existence of interface states in the vicinity of the band gap. Finally, measurements of Schottky barrier height are discussed in an attempt to assess the effects of phase stoichiometry and microstructure on the electrical properties of the Schottky barrier. © 1982.