An Area-Correction Model for Accurate Extraction of Low Specific Contact Resistance

The parasitic factors that strongly influence the measurement accuracy of cross-bridge Kelvin resistors have been extensively discussed during the last few decades. The minimum value of specific contact resistance that can be accurately extracted has been estimated. In this paper, we present an analytical model to account for the actual current flow across the contact and propose an area-correction method for a reliable extraction of specific contact resistance. The model is experimentally verified for low-resistivity (close-to-ideal) metal-to-metal contacts. The minimum contact resistance is determined by the dimensions of the two-metal stack in the area of contact and sheet resistances of the metals used.