BALLISTIC-ELECTRON-EMISSION-MICROSCOPY INVESTIGATION OF HOT-CARRIER TRANSPORT IN EPITAXIAL COSI2 FILMS ON SI(100) AND SI(111)

The attenuation lengths lambda's of hot electrons in thin films of epi taxial CoSi2 on Si(100) and Si(111) were measured as a function of ene rgy using constant-height-mode and constant-current-mode ballistic-ele ctron-emission microscopy (BEEM). Between similar to 1 and similar to 3 eV above the Fermi energy, the lambda's were found to be significant ly anisotropic and their energy dependencies differed strongly from th e free-electron behavior. At higher energies, e(-)-e(-) scattering in CoSi2 was found to be dominant, giving a majority of the BEEM current and largely determining the spatial resolution of both forward and rev erse BEEM imaging, both of which could bk used for direct mapping of i nterfacial steps. Also, constant-height-mode BEEM was used to investig ate the interfacial transport across CoSi2/n-type Si(111), CoSi2/p-typ e Si(111), and CoSi2/n-type Si(100). Evidence for different interfacia l structures of CoSi2/Si(100) was observed.