Negative differential capacitance in ferroelectrics, which can be stabilized using a dielectric, could be used to overcome the limitations of capacitive coupling in electronic devices. However, the use of negative differential capacitance in scaled silicon-based structures—such as those used in advanced low-power logic devices—remains challenging. Here we report the electrical performance enhancement due to negative differential capacitance in metal–oxide–semiconductor capacitors based on ferroelectric zirconium-doped hafnia (Hf0.5Zr0.5O2) with a thickness down to 1 nm. The devices exhibit superior performance to physically thinner control devices without the ferroelectric zirconium-doped hafnia. An S-shaped polarization–electric field relation verifies the negative differential capacitance effect. The effect is also achieved in field-effect transistors in which high-κ hafnia is replaced with the ferroelectric zirconium-doped hafnia, leading to an increase in on current and decrease in off current along with negative drain-induced barrier lowering. The negative differential capacitance exhibits endurance over more than 1015 cycles and can be tuned using doping that controls the interface charges.
Ferroelectric zirconium-doped hafnia (Hf0.5Zr0.5O2) can be used to create negative differential capacitance behaviour in capacitors and transistor gate stacks, providing reliable enhancements in switching performance.