The Effect of Random Dopant Fluctuation on Specific Contact Resistivity

An analytical model is developed to describe the effect of random dopant fluctuation (RDF) on specific contact resistivity $\rho_{c}$. This model accounts for Schottky-barrier (SB) lowering due to image force, interface dipole, and bandgap narrowing effects and is calibrated to TCAD models and previously published experimental results. The contact parameters considered are contact area, SB height, and dopant concentration. The presented analysis suggests that $\rho_{c}$ variation due to RDF will not be significant up to the end of the CMOS roadmap.