Optimization of Cross-Bridge Kelvin Resistor (CBKR) Layout for the Precise Contact Resistance Measurement of TiSi2/n+ Si

This study investigates the impact of cross-bridge Kelvin resistor (CBKR) layout designs on specific contact resistivity (ρc) measurements between TiSi2 and n+ Si. The theoretical ρc is calculated as a function of silicon doping concentration (NSi) and Schottky barrier height (ϕb) to evaluate the measurement value. Various CBKR patterns are fabricated and measured with different contact hole areas (Ac) and aligned margins (δ) to evaluate measurement accuracy. The results show that CBKR with a narrow active width (W) can more accurately measure the ρc compared to the conventional layout mainly attributed to the current path confinement. In addition, if the contact hole length (L) is smaller than the transfer length (LT), the entire Ac contributes to the voltage drop of contact resistance (Rc), resulting in improved measurement accuracy. In contrast, if δ is increased, the measurement error decreases due to current dispersion near the recessed TiSi2 region, which is different from conventional CBKR layouts. Consequently, the measured ρc with an optimized layout shows a close value to the theoretical ρc.