ELECTRICAL CHARACTERIZATION OF THE BETA-FESI2 SI HETEROJUNCTION AFTERTHERMAL-OXIDATION/

The influence of an oxidant ambient on the electrical transport proper ties of beta-FeSi2/Si heterostructures has been investigated. Current- voltage and capacitance-voltage analyses on diodes formed on p-type si licon did not reveal any change in the dominant transport mechanism af ter oxidation, other than an increase of the 0 K hole barrier from 0.4 2 to 0.46 eV. The transport showed a thermally activated process and w as interpreted as thermionic emission of holes from the silicon region to the silicide. However, on n-type silicon a change from a thermally activated process to a tunneling limited transport was observed after oxidation. A multistep recombination-tunneling mechanism was suggeste d with formed defects presumably situated close to the interface or in side the silicide film. It was also observed that dry oxidation was le ss detrimental to the heterojunction characteristics than oxidation in wet ambient. (C) 1996 American Institute of Physics.