Unveiling the Apparent “Negative Capacitance” Effects Resulting From Pulse Measurements of Ferroelectric-Dielectric Bilayer Capacitors

Zhan, Liu; Jiang, Hao; Ordway, Brandon; P., T.

doi:10.1109/led.2020.3020857

Cited by 21 publications

(9 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most FE thin films exhibit internal electric fields with unclear origins, and many speculative explanations have been attempted in the literature. Also, all capacitance–voltage ( C – V ) characteristics or hysteresis measurements performed on FE/DE systems manifest typical signs of high internal fields or back-switching phenomenon − aspects, which are usually not insisted upon.…”

Section: Resultsmentioning

confidence: 99%

“…Until now, the main focus for new applications was the ability to control the switching dynamic by changing the electrostatic conditions for the ferroelectric element using several methods: deposition on a less conductive substrate (e.g., a semiconductor) − by alternating layers with different conductivities and permittivities ,− or by manufacturing super-lattices. − Many published articles are addressing these new applications concerning ferroelectricity obtained in doped HfO 2 , a material that is compatible with Si and is already used in the complementary metal-oxide semiconductor technology, or complex structures with improved characteristics. However, there are a limited number of studies focusing on understanding the complex relationship between polarization switching dynamics in ferroelectrics and external electrostatic conditions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Negative Capacitance and Switching Dynamics Control Via Non-Ferroelectric Elements

Boni

Pătru

Filip

et al. 2022

ACS Appl. Energy Mater.

View full text Add to dashboard Cite

Complex ferroelectric structures with dielectric inter-layers may become possible alternatives for neuromorphic computing and low-power field-effect transistors since they exhibit multiple polarization states and negative capacitance. However, the effects on the switching characteristics due to the electric properties of the non-ferroelectric circuit element have not been clearly evaluated so far. A high-resistance or low-capacitance element is usually associated with an increased depolarization field and eventually with suppression of polarization but without further consideration of the electrostatic differences. Therefore, we show that switching behavior is dramatically changed if the non-FE element is a resistive component or a capacitive one. This is reflected by either an increased apparent coercive field or imprint, respectively. A negative capacitance regime was observed at different moments but strongly depends on the nature of the non-ferroelectric element. The voltage on the ferroelectric component remains constant during switching, which is a fingerprint of the system passing through non-equilibrium states. Therefore, we propose an algorithm to recover the S-shape of polarization dependence on the ferroelectric internal voltage during the slowed transition between the two stable states of polarization.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Negative Capacitance and Switching Dynamics Control Via Non-Ferroelectric Elements

Boni

Pătru

Filip

et al. 2022

ACS Appl. Energy Mater.

View full text Add to dashboard Cite

show abstract

“…Therefore, the relationship between the displacement field D and the Helmholtz free energy terms h tot , h h , and h ih could be acquired, as shown in Figure 1b, by using δ as a parameter. h DE in Figure 1b was plotted using Equation (11) while assuming that the single DE layer had the same displacement field. The following values were used for effective display of the results: a 1 = − 2.26 × 10 7 V ⋅ m C −1 , a 11 = 1.37 × 10 8 V ⋅ m 5 C −2 , a 111 = 2.76 × 10 9 V ⋅ m 9 C −5 , ε a = 50, ε c = 50, ε d = 8.9, t f = 25 nm, t d = 5 nm, P s = 0.2 C m −2 , and λ = 0.1.…”

Section: Derivation Of the Helmholtz Free Energy Density-displacement...mentioning

confidence: 99%

“…This corresponds to a negative permittivity region when the U-P curve is converted into a polarization-voltage (P-V) curve. This peculiar property of FE materials has generated several novel ideas, [4] including the negative capacitance (NC) effect [5][6][7][8][9][10][11] in DE/FE stacked structures.…”

mentioning

confidence: 99%

Negative Capacitance from the Inhomogenous Stray Field in a Ferroelectric–Dielectric Structure

Park

Hwang

2022

Adv Funct Materials

View full text Add to dashboard Cite

The phenomenological Landau–Ginzburg–Devonshire model provides a fundamental background for an understanding of the peculiar charge–voltage behavior of ferroelectric (FE) materials. However, the model cannot explain the polarization behavior of multidomain FE materials. The experimentally observed negative capacitance (NC) effect, which is interpreted as an emergence of the Landau barrier effect, involves particular conceptual difficulty. This work provides a new conceptual framework to explain the quasi‐static NC effect based on the energy formula for a stacked dielectric/ferroelectric (DE/FE) layer structure with the multidomain configuration with arbitrary shape. The presence of such domain configuration causes the energy–displacement curve of the inhomogenous Helmholtz energy term to have negative curvature. This is caused by the stray field between the neighboring domains. The model can be further extended to the DE/FE system with polycrystalline FE grains using the advanced phase‐field analysis. It is determined that the NC effect from the stray field is a universal phenomenon. These models provide quantitative explanations for the previously reported short‐pulse measurement results for various DE/FE material systems, which have lacked accurate interpretations.

show abstract

“…However, the physical mechanisms for these observations are still not clear. For example, Liu et al have recently proposed an alternative perspective on such experimental observations [23]. Therefore, it is of great importance to further explore the underlying physical mechanisms for such prospective experimental evidence of NC stabilization.…”

Section: Introductionmentioning

confidence: 99%

Physical Mechanism behind the Hysteresis-free Negative Capacitance Effect in Metal-Ferroelectric-Insulator-Metal Capacitors with Dielectric Leakage and Interfacial Trapped Charges

Hsu,

Chang,

Nikonov

et al. 2020

Preprint

View full text Add to dashboard Cite

The negative capacitance (NC) stabilization of a ferroelectric (FE) material can potentially provide an alternative way to further reduce the power consumption in ultra-scaled devices and thus has been of great interest in technology and science in the past decade. In this article, we present a physical picture for a better understanding of the hysteresis-free charge boost effect observed experimentally in metal-ferroelectric-insulator-metal (MFIM) capacitors. By introducing the dielectric (DE) leakage and interfacial trapped charges, our simulations of the hysteresis loops are in a strong agreement with the experimental measurements, suggesting the existence of an interfacial oxide layer at the FE-metal interface in metal-ferroelectric-metal (MFM) capacitors. Based on the pulse switching measurements, we find that the charge enhancement and hysteresis are dominated by the FE domain viscosity and DE leakage, respectively. Our simulation results show that the underlying mechanisms for the observed hysteresis-free charge enhancement in MFIM may be physically different from the alleged NC stabilization and capacitance matching. Moreover, the link between Merz's law and the phenomenological kinetic coefficient is discussed, and the possible cause of the residual charges observed after pulse switching is explained by the trapped charge dynamics at the FE-DE interface. The physical interpretation presented in this work can provide important insights into the NC effect in MFIM capacitors and future studies of low-power logic devices.

show abstract

Unveiling the Apparent “Negative Capacitance” Effects Resulting From Pulse Measurements of Ferroelectric-Dielectric Bilayer Capacitors

Cited by 21 publications

References 19 publications

Negative Capacitance and Switching Dynamics Control Via Non-Ferroelectric Elements

Negative Capacitance and Switching Dynamics Control Via Non-Ferroelectric Elements

Negative Capacitance from the Inhomogenous Stray Field in a Ferroelectric–Dielectric Structure

Physical Mechanism behind the Hysteresis-free Negative Capacitance Effect in Metal-Ferroelectric-Insulator-Metal Capacitors with Dielectric Leakage and Interfacial Trapped Charges

Contact Info

Product

Resources

About