Negative capacitance from the inductance of ferroelectric switching

Abstract

Negative capacitance (NC) has been proposed to realize sub-Boltzmann steep-slope transistors in recent years. We provide experimental evidences and theoretical view for ferroelectric NC and inductance induced by polarization switching, based on an as-deposited nanoscale ferroelectric zirconium oxide (ZrO 2) layer (nano-f-ZrO 2). The experimental results are demonstrated in nano-f-ZrO 2 , including resistor-inductor-capacitor oscillations, positive reactance in Nyquist impedance plot, enhancement of capacitance, and sub-60 mV/dec subthreshold swing of nanoscale transistors. The theoretical analysis shows that ferroelectric polarization switching yields an effective electromotive force which is similar in behavior to Lenz's law, leading to inductive and NC responses. Nano-beam electron diffraction reveals ferroelectric multi-domains in nano-f-ZrO 2. Under small-signal operation, the switching of net polarization variation in ferroelectric multi-domains contributes to the ferroelectric inductance and NC. Nano-f-ZrO 2 provides a pronounced inductance compared to conventional inductors, which would have impacts in a variety of applications including transistors, filters, oscillators, and radio-frequency-integrated circuits.

Anomalous Motion of Charged Domain Walls and Associated Negative Capacitance in Copper–Chlorine Boracite

“…In both cases, a local electric field opposing the macroscopically applied one develops, [33] due to the presence of a static capacitance [34,35] or during switching under the application of large electric fields. [34,[36][37][38] In all cases, it is worth noting that, macroscopically, the overall capacitance of the system remains positive. [33] To check the local field behavior in the boracite during anomalous domain wall motion, in situ Kelvin probe force micro scopy (KPFM) imaging was performed across a 90° Figure 5.…”

Evidence of Negative Capacitance and Capacitance Modulation by Light and Mechanical Stimuli in Pt/ZnO/Pt Schottky Junctions

“…Despite being observed experimentally for several years [ 1 , 2 , 3 ], negative capacitance (NC) phenomena recently aroused substantial interest due to the growing demand for miniaturized electronic devices and applications. Negative capacitance has already been widely studied in ferroelectric-dielectric structures [ 4 , 5 , 6 , 7 ] to improve the subthreshold swing and internal voltage amplification of transistors [ 8 , 9 ]. Moreover, achieving negative capacitance for inductors over a large frequency range would constitute a breakthrough for broadband impedance matching in radio frequency applications [ 10 ].…”

Recent Studies on Supercapacitors with Next-Generation Structures

“…Measurements were conducted with an impedance analyzer in the frequency range from 1 MHz to 10 mHz at 1 V direct current (DC) voltage and 10 mV alternating current (AC) perturbation. You can see that the RC circuit (shown in the inset of Figure 11 ) gives a semi-circle of negative imaginary impedance in the Nyquist plot [ 52 ].…”