Analysis and scaling of Kelvin resistors for extraction of specific contact resistivity

An accurate numerical analysis of Kelvin resistors used for direct interfacial contact resistance measurements is presented. Curves that allow extraction of true specific contact resistivity from measured specific contact resistivity are given for different ratios of square contact window size (l) to square diffusion tap width (w). Scaling transformations are proposed to extract curves for different feature sizes. It has been shown that when l is made smaller than w, the extracted value of the specific contact resistivity (ρce) can be significantly higher than the true specific contact resistivity (ρc), especially for low values of ρc.