Patent ID: 8854067

Claim:
A method of determining a contact resistance of a conductor deposited on a substrate during combinatorial processing, wherein the substrate comprises a semiconductor, the method comprising: a) providing the substrate, wherein the substrate comprises a plurality of site isolated regions; b) providing a Circular Transmission Line Method (CTLM) structure on at least one site isolated region, wherein the CTLM structure comprises: i) an inner conducting region surrounded by an outer conducting region, wherein the outer conducting region is separated from the inner conducting region by an annular gap; and, ii) a first voltage sensing electrode in electrical contact with the inner conducting region and a second voltage sensing electrode in electrical contact with the outer conducting region; and, iii) a first current forcing electrode in electrical contact with the inner conducting region and a second current forcing electrode in electrical contact with the outer conducting region; c) applying a constant current between the inner conducting region and the outer conducting region through the first current forcing electrode and the second current forcing electrode; d) measuring a voltage difference between the inner conducting region and the outer conducting region for each of a plurality of values of constant current, and determining a total resistance from the slope of the line; and, e) repeating steps b)-d), for each of a plurality of sizes of the annular gap, and determining therefrom the contact resistance.