Physical Insights on Steep Slope FEFETs including Nucleation-Propagation and Charge Trapping

Yang, Xiudi; Verhulst, Anne S.; Parvais, B.; Horiguchi, N.; Groeseneken, G.; Houdt, J. Van; Bardon, M. Garcia; Alam, Nur K.; Thesberg, Mischa; Kaczer, B.; Roussel, Ph.; Popovici, Mihaela; Ragnarsson, L.-Å.; Truijen, Brecht

doi:10.1109/iedm19573.2019.8993492

Cited by 14 publications

(17 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3b-d show that, all else being equal, an increase in D FI results in a (worsened) hysteretic device operation and an internal voltage amplification effect that derives from transient, instead of quasi-static, polarization switching dynamics. Note that our finding of increased hysteretic device operation with D FI is in agreement with theoretical predictions using a kinetics-based model for the polarization switching 65 , and the experimental observation that the memory window of a device increases with the trap density 66 .…”

Section: Resultssupporting

confidence: 90%

Thermodynamic equilibrium theory revealing increased hysteresis in ferroelectric field-effect transistors with free charge accumulation

et al. 2021

View full text Add to dashboard Cite

At the core of the theoretical framework of the ferroelectric field-effect transistor (FeFET) is the thermodynamic principle that one can determine the equilibrium behavior of ferroelectric (FERRO) systems using the appropriate thermodynamic potential. In literature, it is often implicitly assumed, without formal justification, that the Gibbs free energy is the appropriate potential and that the impact of free charge accumulation can be neglected. In this Article, we first formally demonstrate that the Grand Potential is the appropriate thermodynamic potential to analyze the equilibrium behavior of perfectly coherent and uniform FERRO-systems. We demonstrate that the Grand Potential only reduces to the Gibbs free energy for perfectly non-conductive FERRO-systems. Consequently, the Grand Potential is always required for free charge-conducting FERRO-systems. We demonstrate that free charge accumulation at the FERRO interface increases the hysteretic device characteristics. Lastly, a theoretical best-case upper limit for the interface defect density DFI is identified.

show abstract

Section: Resultssupporting

confidence: 90%

Thermodynamic equilibrium theory revealing increased hysteresis in ferroelectric field-effect transistors with free charge accumulation

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The FeFET model adopts a composite FE-MOS system selfconsistently coupled in transient [19] (Fig. 3).…”

Section: A Fefet CM Frameworkmentioning

confidence: 99%

“…3. Schematic of the transient FE-MOS solution in the FeFET CM, where the dual-way ("ψs-to-VFE" and "VFE-to-Vint") self-consistent loop is calculated at every time instant [19]. Fig.…”

Section: B Discretized Ferroelectric Polarization Switchingmentioning

confidence: 99%

“…The validation of the "CT-alone" model can be found in our prior works [18,19] on non-FeFET hardware. For FeFET, the major complications are 1) the increase of inversion carrier density n due to switched-up PFE and 2) the modification of VFE through depolarization field [18], both of which will influence the capture/emission rate constants as shown in Fig.…”

Section: Two-state Nmp Charge Trapping Modelmentioning

confidence: 99%

“…domain switching dynamics [6,8,9]. This paper thus reports on a comprehensive FeFET CM aimed at addressing the aforementioned issues on the basis of our recent works [18,19]. The paper is organized as follows.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Compact Modeling of Multidomain Ferroelectric FETs: Charge Trapping, Channel Percolation, and Nucleation-Growth Domain Dynamics

Yang

Bardon

Kaczer

et al. 2021

IEEE Trans. Electron Devices

Self Cite

View full text Add to dashboard Cite

The (doped-)hafnia-based ferroelectric FET (FeFET) is a promising candidate for low-power non-volatile memories and shows potential use as a steep-slope lowpower logic device. This requires accurate modeling of the metal-ferroelectric-insulator-silicon (MFIS) gate stack electrostatics. Here we present a hardware-validated FeFET compact model that resolves three key aspects in the MFIS electrostatics pertaining to a multi-domain ferroelectric (FE) layer: 1) the non-radiative multi-phonon process-based charge trapping, 2) the source-to-drain channel percolation due to spatial non-uniformity of FE domain switching and 3) the nucleation-growth domain reversal dynamics using a phenomenological formalism. The polarization charge is calculated by discretized domain switching in transient under distributed coercive fields. Based on the comparison of the model versus experimental data on Hf0.5Zr0.5O2 n-FeFET hardware, we prove that the onset of FE VTH lowering starts with the source-to-drain percolation path formation, when enough FE domains have been flipped up by the gate bias. We further demonstrate that the field-independent domain growth is the fundamental origin of the measured steep subthreshold slope during the downward ID-VG sweep. The model ultimately aims to lay down the groundwork for a unified FeFET compact model for both memory-and logic-oriented applications.

show abstract

From Ferroelectric Material Optimization to Neuromorphic Devices

et al. 2023

View full text Add to dashboard Cite

Due to the voltage driven switching at low voltages combined with nonvolatility of the achieved polarization state, ferroelectric materials have a unique potential for low power nonvolatile electronic devices. The competitivity of such devices is hindered by compatibility issues of well‐known ferroelectrics with established semiconductor technology. The discovery of ferroelectricity in hafnium oxide changed this situation. The natural application of nonvolatile devices is as a memory cell. Nonvolatile memory devices also built the basis for other applications like in‐memory or neuromorphic computing. Three different basic ferroelectric devices can be constructed: ferroelectric capacitors, ferroelectric field effect transistors and ferroelectric tunneling junctions. In this article first the material science of the ferroelectricity in hafnium oxide will be summarized with a special focus on tailoring the switching characteristics towards different applications.The current status of nonvolatile ferroelectric memories then lays the ground for looking into applications like in‐memory computing. Finally, a special focus will be given to showcase how the basic building blocks of spiking neural networks, the neuron and the synapse, can be realized and how they can be combined to realize neuromorphic computing systems. A summary, comparison with other technologies like resistive switching devices and an outlook completes the paper.

show abstract

Physical Insights on Steep Slope FEFETs including Nucleation-Propagation and Charge Trapping

Cited by 14 publications

References 0 publications

Thermodynamic equilibrium theory revealing increased hysteresis in ferroelectric field-effect transistors with free charge accumulation

Thermodynamic equilibrium theory revealing increased hysteresis in ferroelectric field-effect transistors with free charge accumulation

Compact Modeling of Multidomain Ferroelectric FETs: Charge Trapping, Channel Percolation, and Nucleation-Growth Domain Dynamics

From Ferroelectric Material Optimization to Neuromorphic Devices

Contact Info

Product

Resources

About