Dependence of contact resistivity on impurity concentration in CorSi systems

We have investigated the contact resistivity of CorSi contact systems with the implantation of Bq ions in the doping range from 3=1014 to 1=1016 cmy2. The concentrations of electrically activated B atoms are limited by the solubility in Si substrates for the doses above 5=1015 cmy2 at annealing temperatures of 900–11008C and the measured contact resistivities are also ruled by those concentrations. The contact resistivities in the high impurity concentration are theoretically calculated based on a tight-binding model in consideration of the formation of impurity bands and band edge tails. The calculated results are in good agreement with the measured values, and a minimum contact resistivity is obtained to be 1.3=10y7 V cm2 for samples with a dose of 1=1016 cmy2. q2000 Elsevier Science B.V. All rights reserved