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Physical Insights on Steep Slope FEFETs including Nucleation-Propagation and Charge Trapping Host Publication: 65th Annual IEEE International Electron Devices Meeting, IEDM 2019 Authors: Y. Xiang, A. Verhulst, B. Parvais, N. Horiguchi, G. Groeseneken, M. Garcia Bardon, M. Nur K. Alam, M. Thesberg, B. Kaczer, P. Roussel, M. I. Popovici and L. A. Ragnarsson Publisher: Institute of Electrical and Electronics Engineers Inc Publication Date: Dec. 2019
Abstract: We present a kinetics-based analysis of the steep slope operation of ferroelectric (FE) FETs built on (i) a statistical multidomain nucleation-propagation mechanism of FE polarization switching and (ii) charge trapping in the high- K FE oxide. With a hardware-validated compact model we predict the change in hysteresis direction, the steep slope and the transient behaviors observed in our I-V measurements on Hf0 5Zr0 5O2-based planar n-FEFETs. We find that the proposed field-independent propagation is essential in explaining the measured reverse-sweep steep slope and transient current drift. Furthermore, the model suggests that a higher polarization and accordingly a larger I-V hysteresis are induced upon increased trapping. Finally, we show that for hafnia-based FE oxides, reliability engineering of defect band is needed for obtaining steep slope in scaled logic-FEFETs.
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