High performance negative capacitance field-effect transistor featuring low off-state current, high on/off current ratio, and steep sub-60 mV dec−1 swing.

In this work, we demonstrated that the 5-nm-thick HfAlO_x negative capacitance transistor (NCFET) with optimized Al doping can achieve a minimum 33 mV dec⁻¹ subthreshold swing (SS), an ultralow I_off of 7.44 fA μm⁻¹, and a high I_on/I_off ratio of 1.9 × 10⁸. The NC switching with sub-60 mV dec⁻¹SS can be implemented from V_DS = 0.2 V to 0.8 V due to an ultralow off-state leakage current. The experimental results reveal that well-controlled Al doping in HfAlO_x not only reduces off-state leakage of the transistor, but also improves the ferroelectric NC effect to achieve a sub-60 mV dec⁻¹ switching under a favorably low sub-1 voltage. This scaled HfAlO_x NCFET with optimized Al doping and fluorine defect passivation shows the great potential for the application of low power logic devices. [ABSTRACT FROM AUTHOR]