This Is AuburnElectronic Theses and Dissertations

RF Characterization and Modeling of 14nm RF FinFETs




Zhang, Jiabi

Type of Degree

PhD Dissertation


Electrical and Computer Engineering

Restriction Status


Restriction Type

Auburn University Users

Date Available



This work focuses on the characterization and compact modeling of RF characteristics of both n- and p-channel transistors fabricated using 14-nm FinFET technologies. DC I-V, as well as its higher order derivatives, C-V, S-parameters and two-tone intermodulation linearity are experimentally measured and modeled using BSIM-CMG compact model. Third order intermodulation distortion is examined using experimental measurements, circuit simulation with BSIM-CMG, and Volterra series analysis. Linearity sweet spots with respect to gate voltage and input power, as well as drain voltage dependence, are examined. A strategy for extracting BSIM-CMG model parameters for fitting intermodulation in addition to DC I-V, C-V and S-parameters is developed and demonstrated. Key BSIM-CMG model parameters are identified for simultaneously fitting DC I-V, C-V, Y-parameters and intermodulation distortion. Volterra series analysis shows that distortions resulting from $V_{DS}$ dependence of $I_{DS}$ well dominate over distortions from $V_{GS}$ dependence of $I_{DS}$. Third order intercept gate voltage ($V_{GS,IP3}$) is extracted from frequency dependence of IIP3. A worst case $V_{GS,IP3}$ of 0.5V is observed, compared to 0.7V in a 28-nm high-k metal gate planar device. Comparison is made between NMOS and PMOS on DC and RF characteristics. Compared to NMOS, PMOS shows larger $I_{DS}$, $g_m$ and $g_{o}$, comparable $f_T$, lower $f_{max}$ at minimum length, better IP3 over a large bias range, and a lower distortion at higher RF power. A larger $V_{GS,IP3}$ is observed in PMOS at higher $V_{GS}$ when $V_{DS}$ is relatively high.