A5067117710- Ferroelectric and Negative Capacitance Devices
- Semiconductor materials and devices
- Advanced Memory and Neural Computing
- MXene and MAX Phase Materials
- Ferroelectric and Piezoelectric Materials
- Advanced Sensor and Energy Harvesting Materials
- Network Packet Processing and Optimization
- Advancements in Semiconductor Devices and Circuit Design
- Electronic and Structural Properties of Oxides
Zhejiang Lab
2023-2025
We have proposed and experimentally demonstrated a novel multi-bit content addressable memory (CAM) cell based on two series connected ferroelectric FETs (FeFETs). Thanks to the multilevel (MLC) operations of FeFETs complementary inputs search lines (SLs), CAM functions with 2-bits/cell are realized. Bit density can be further boosted by implementing more stable states FeFETs. In addition, cells integrated in form 3D vertical FeFET NAND, which enables ultra-high energy efficiency at low...
We have experimentally investigated disturb-free operations of multilevel cell (MLC) ferroelectric field-effect transistors (FeFETs) in a NAND array. The fabricated FeFET cells are systematically characterized, and optimized schemes to write into multiple states with high stability investigated. Write read achieve stable MLC arrays proposed. For the realization operations, both program disturbs characterized at array level. In addition, margins inhibition voltage ( <inline-formula...
We have experimentally demonstrated that the ferroelectricity can be controlled by reversibly injecting oxygen vacancies ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {o}}{)}$ </tex-math></inline-formula> from interfacial layer (IL) of TiOxNy to Hf notation="LaTeX">$_{{0}.{5}}$ Zr0.5O2(HZO) or extracting them HZO IL in titanium nitride (TiN) notation="LaTeX">$/$ TiN structure for first time....
We have experimentally and theoretically confirmed that the ferroelectric fatigue recovery in doped-HfO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> under external electric field (E xmlns:xlink="http://www.w3.org/1999/xlink">ext</inf> ) is dominated by redistribution of oxygen vacancies (V xmlns:xlink="http://www.w3.org/1999/xlink">o</inf> ), rather than charge detrapping effects. The low E mainly due to non-uniform distribution V...
We have experimentally studied resistance switching and carrier transport mechanisms of HfO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\text{2}}$</tex-math> </inline-formula> -based ferroelectric diode (FD) by systematic measurement as well current fitting with possible models. FD TiN/HZO/Al O notation="LaTeX">$_{\text{3}}$</tex-math> /IGZO structure is fabricated a low thermal budget 400...
Antiferroelectric (AFE) ZrO2-based devices are anticipated to exhibit superior endurance properties in comparison their ferroelectric (FE) counterparts. Nevertheless, the underlying mechanisms of AFE remain elusive. In this study, guided by dynamic evolution oxygen vacancies (Vo), we reveal three kinds fatigue HfxZr1−xO2 (HZO) during uni-directional cycling. The first mechanism is related interfacial Vo charge trapping, which accelerates switching from P↓↑ state P↓↓ state, leading extrinsic...
In this work, the impact of read scheme together with polarization state ferroelectric (FE) domains on interface trap behavior FeFETs for NOR array applications were investigated. Hf <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</inf> Zr O xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> (HZO)-based FeFET different interfacial layer (IL) treatments fabricated and used analysis. Generally, as gate voltage <tex...
We have characterized polarization switching kinetics of Hf0.5Zr0.5O2 (HZO) at cryogenic temperature (T) down to 100 K. By the nucleation-limited-switching model with Lorentzian distribution fittings, dependences average time (log τ1) and (ω) on T are extracted. As decreases from 300 K, log τ1 first rapidly then gradually stabilizes. Meanwhile, ω exhibits different trends under external electric fields (Eext), decreasing low Eext while increasing high Eext, eventually stabilizing non-zero...
A physics-based model and its corresponding solution methodology for the mobile-ionic (MI) dielectrics exhibiting charge–voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> – notation="LaTeX">$V$ ) hysteresis behaviors are proposed based on ion drift-diffusion (IDD) equations coupling with Poisson's equation. The captures dynamic distribution of mobile ions'...
We have investigated polarization-induced temperature instability (PTI) of HfO2-based ferroelectric field-effect transistor (FeFET) and reveal its mechanisms. Since the existence spontaneous polarization in ferroelectric, an internal bias emerges even without applied gate voltage, which results performance degradation that can be accelerated under high-temperature stress (HTS). By systematically characterizing PTI, we find FeFET suffers from strong positive PTI including subthreshold swing...
This paper proposes a physics-based model of ferroelectric field-effect transistors (FeFETs) considering the migration mobile ions in $HfO_{2}$-based dielectrics. The is based on ion drift-diffusion (IDD) equations, time-dependent Ginzburg-Landau (TDGL) equation, coupling with Poisson's and semiconductor charge/transport equations. effects characteristics are investigated detail by developed which verified calibrated measurement results $Hf_{0.5}Zr_{0.5}O_{2}$ (HZO). It proved that HZO films...