We have investigated hot electron transmission across epitaxial metal-disilicide/n-Si(111) interfaces using ballistic electron emission microscopy (BEEM). Different crystal orientations of epitaxial NiSi(2) were grown on a Si(111) substrate using molecular beam epitaxy. The presence of different interfaces of NiSi(2) on Si(111) were confirmed by high resolution transmission electron microscopy. Electrical transport measurements reveal a clear rectifying Schottky interface with a barrier height of 0.69 eV. However, using BEEM, three different regions with different transmissions and Schottky barrier heights of 0.65 eV, 0.78 eV, and 0.71 eV are found. The addition of a thin Ni film on the NiSi(2) layer strongly reduces the transmission in all the three regions and interestingly, almost equalizes the transmission across them. (C) 2011 American Institute of Physics. [doi:10.1063/1.3610458]