Evaluation of ultra-low specific contact resistance extraction by cross-bridge Kelvin resistor structure and transmission line method structure

This work evaluates the accuracy of the specific contact resistance extraction by the cross-bridge Kelvin resistor (CBKR) structure and the self-aligned transmission line method (mTLM) structure considering three-dimensional effect. The mTLM structure is more accurate than the CBKR structure in theory but more sensitive to process variation. The sensitivity to process variation could be suppressed by averaging large amount data. Nevertheless, the recessed contact interface would underestimate the true specific contact resistance and would cause complicated extraction problem for both test structures as the contact resistivity becomes less than 10^-8 ohm-cm².