Intermodulation Linearity Characteristics of 14-nm RF FinFETs

This paper investigates the RF intermodulation characteristics of transistors from a 14-nm RF FinFET technology using experimental measurements, circuit simulation with Berkeley short-channel IGFET model-common multi-gate (BSIM-CMG), and Volterra series. Linearity sweet spots with respect to gate voltage and RF power, as well as its drain voltage dependence, are examined. Key BSIM-CMG model parameters required for simultaneous fitting of dc I-V, S-parameters, and intermodulation distortion are identified and demonstrated. Volterra series analysis shows that distortion resulting from VDS derivatives of IDS dominates at most biases. A minimum third-order intercept gate voltage VGS,IP3 of 0.5 V is observed, compared with 0.7 V in a 28-nm high-k metal-gate planar device.