A ferroelectric negative-capacitance (NC) transistor using aluminum-doped hafnium oxide (HfAlOx) with fluorine passivation is successfully demonstrated. The fluorine-passivated device shows a nearly hysteresis-free forward/reverse swing of sub-30 mV dec−1 for symmetric switch, a wide sub-60 mV (dec·swing)−1 range over 4 decades of drain current, an ultralow off-leakage current of 4 fA μm−1, and a high on/off current ratio of >108. The fluorine defect passivation (FP) reduces oxygen vacancies of ferroelectric HfAlOx to mitigate interface depolarization field and thereby reinforce surface potential amplification effect during NC operation.
Cheng, C. H., Fan, C. C., Hsu, H. H., Wang, S. A., & Chang, C. Y. (2019, February 1). Improved Negative-Capacitance Switch of Ferroelectric Field Effect Transistor Using Defect Passivation Engineering. Physica Status Solidi - Rapid Research Letters. Wiley-VCH Verlag. https://doi.org/10.1002/pssr.201800493