Work Functions of the transition Metals and Metal Silicides

The work functions of polycrystalline metals are often used to systematize Schottky barrier height data for rectifying contacts to semiconductors. Rectifying contacts to silicon devices are predominantly formed using conductive metal silicides with work functions which are not as well characterized as metal work functions. The present work has two objectives. First, it classifies the transition metals using correlations between the metal work function and the atomic chemical potential. Second, the available data for metal silicides is collected and interpreted using an average charge transfer (ACT) model. The ACT model accounts for the electronic hardness of the component elements in addition to their chemical potentials. New trends in the behavior of silicide work functions are identified.