Accurate Estimation of Low ( < 10 − 8 Ω · cm 2 ) Values of Specific Contact Resistivity

Advancements in nanotechnology have created the need for efficient means of communication of electrical signals to nanostructures, which can be addressed using low resistance contacts. In order to study and estimate the resistance of such contacts or the resistance posed by the interface(s) in such contacts, accurate test structures and evaluation techniques need to be used. The resistance posed by an interface is quantified using its specific contact resistivity (SCR), and although multiple techniques have been utilized, inaccuracies of such techniques in measuring values of SCR lesser than 10−8 Ω · cm have been reported. In this letter, an approach for estimating very low values of SCR (lower than the previously limiting 10−8 Ω · cm) using a cross Kelvin resistor test structure is demonstrated using aluminum to titanium silicide ohmic contacts, with a minimum estimated SCR value of 6.0 × 10−10 Ω · cm.