Ballistic-electron-emission microscopy and related ballistic-hole and carrier-scattering spectroscopies have been used to investigate carrier transport in the epitaxial ${\mathrm{CoSi}}_2$/Si system. An unexpected degree of variation in interface transmission is observed despite the high crystal quality of the epitaxial silicide layer. Furthermore, clear evidence of the ${\mathrm{CoSi}}_2$ band structure is observed, which has a dramatic effect on interface transport. The major effect of the silicide band structure is to increase the interfacial barrier to electron transmission to a value in excess of the Schottky barrier height.

• Received 24 May 1991

DOI:https://doi.org/10.1103/PhysRevB.44.6546