Accurate contact resistivity extraction on Kelvin structures with upper and lower resistive layers

An accurate procedure to extract contact resistivity from contact resistance measurements made on both D-resistor and L-resistor type Kelvin cross test structures with both upper and lower resistive layers is presented. Through computer simulation it can be shown that the collar effects of both upper and lower layers are additive when both layers have a symmetric geometry. The method is based on the determination of a set of "universal curves" through computer simulation. Using dimensionless variables, these curves can be employed in all experimental conditions, eliminating the need of further simulations.