SPATIAL VARIATIONS OF HOT-CARRIER TRANSMISSION ACROSS COSI2 SI INTERFACES ON A NANOMETER-SCALE/

In situ ballistic-electron-emission microscopy (BEEM) and spectroscopy have been performed at 77 K on epitaxial CoSi2 films on n-Si(100) and Si(111) of both doping types. Two different mechanisms have been iden tified, by which structural defects at these interfaces give rise to v ariations of the carrier transmission across the interface on a nanome ter scale: On CoSi2/Si(111) interfacial misfit dislocations locally en hance the scattering probability at the interface. By the same mechani sm individual interfacial point defects can be resolved in BEEM images . No variations of the Schottky barrier have been observed at this int erface. In contrast, on CoSi2/Si(100), certain interfacial dislocation s and other defects lower the Schottky barrier by up to 0.1 eV on a na nometer scale.