Device Characterization and Threshold Voltage Extraction of Multi-VT Transistors in UMC 65nm Technology: A Methodological Approach

Accurate threshold voltage (Vth) extraction is crucial for NMOS and PMOS device design in advanced technologies like UMC 65 nm. This paper compares six Vth extraction methods - Constant Current (CC), Extrapolated Linear Region (ELR), Transconductance Linear Extrapolation (GMLE), Second Derivative (SD), Ratio, and Second Derivative Logarithmic (SD Log) across LVT, HVT, NVT, and RVT transistors. The study evaluates each method's sensitivity to parasitic resistances and mobility degradation and quantitatively assesses noise filtering for second derivative-based methods. The GMLE method yields the lowest Vth values, while the Ratio method provides higher estimates with implications for real-world device performance. This comparison offers a practical guide for selecting the most suitable Vth extraction technique based on specific application needs.