Key Takeaways & Executive Findings
- •• • OS-channel FeFET achieves V_pass as low as 1 V, compared to 5–10 V for conventional QLC NAND, reducing string-level power consumption by over 80% in read/write operations. • • The memory window exceeds 11 V with a 5-nm-thick SiO2 interlayer, enabling 5-bit-per-cell (PLC) operation, a 25% increase in storage density over current 4-bit QLC NAND. • • The high-k Ta2O5 interlayer acts as an oxygen diffusion barrier, preventing interfacial defects and off-current degradation, addressing a critical reliability issue in prior OS-based FeFETs. • • The near-zero V_th, achieved by suppressing the 'down' polarization state in the IGZO channel, eliminates the need for high V_pass to activate unselected cells, directly tackling the power bottleneck in 3D NAND scaling.
Abstract
The escalating power consumption of 3D NAND flash memory, driven by the need for high pass voltages (V_pass) to read cells in vertically stacked strings, poses a critical challenge as layer counts approach 1000. Conventional charge-trap NAND requires V_pass of 5–10 V for quad-level cell (QLC) operation, while silicon-channel ferroelectric NAND suffers from limited memory windows due to low-k interlayers. Here, we highlight a breakthrough by Yoo et al. that introduces an oxide semiconductor (OS)-channel ferroelectric field-effect transistor (FeFET) with a gate stack comprising a zirconium-doped hafnium oxide (HZO) ferroelectric layer sandwiched between low-k (SiO2/SiNx) and high-k (Ta2O5) interlayers, and an indium gallium zinc oxide (IGZO) channel. The absence of hole carriers in IGZO suppresses the 'down' polarization state, enabling a near-zero threshold voltage (V_th) and reducing V_pass to as low as 1 V. The high-k Ta2O5 interlayer prevents oxygen diffusion, mitigating off-current degradation, while the low-k SiO2/SiNx interlayer enhances charge trapping, yielding a memory window exceeding 11 V for a 5-nm SiO2 layer. This enables 5-bit-per-cell (penta-level cell, PLC) operation, surpassing current QLC NAND. The combination of ultralow V_pass and wide memory window achieves both low power consumption and high storage density, positioning OS-channel FeFETs as a promising solution for next-generation memory systems.
1. Introduction
The fundamental challenge in 3D NAND flash memory arises from its vertical architecture, where thousands of cells are stacked in a string. Reading a single cell requires applying a high pass voltage (V_pass) to all other cells to exceed their maximum threshold voltage (V_th), a process that consumes significant power. As layer counts approach 1000, this energy demand becomes unsustainable, driving up electricity costs in data centers and reducing battery life in mobile devices. Conventional charge-trap NAND, the dominant technology, relies on electron injection for programming, which shifts the memory window toward positive voltages, limiting the ability to reduce V_pass without compromising multi-level performance. For instance, quad-level cell (QLC) NAND requires V_pass of 5–10 V to maintain 4-bit operation. Silicon-channel ferroelectric NAND reduces write voltages but suffers from limited memory windows due to low-k interlayers that hinder charge screening and reliability.
Previous attempts using oxide semiconductor (OS) channels in ferroelectric field-effect transistors (FeFETs) faced obstacles such as off-current degradation and architectural incompatibility, stemming from the absence of holes in the oxide channel, which caused non-ideal polarization switching and interface defects. The breakthrough by Yoo et al. addresses these bottlenecks through a precisely engineered device architecture that reconfigures both the gate stack and the channel material. By incorporating a zirconium-doped hafnium oxide (HZO) ferroelectric layer sandwiched between low-k (SiO2/SiNx) and high-k (Ta2O5) interlayers, along with an indium gallium zinc oxide (IGZO) channel, the device achieves a near-zero V_th and a wide memory window exceeding 11 V. This dual-interlayer design not only suppresses the 'down' polarization state but also prevents oxygen diffusion, overcoming the tradeoff between power consumption and memory performance. The result is a FeFET that operates with V_pass as low as 1 V and supports 5-bit-per-cell (PLC) operation, setting new benchmarks for NAND technology.
Loading authentic research manuscript (Pages 1–5)...
Yuhan Hu, Liang Chu (2026). Oxide-channel ferroelectric transistor enables ultralow-power NAND flash technology. SCIENCE CHINA Materials. https://doi.org/10.1007/s40843-026-4023-8
Research & Educational Purpose Only: The translations, structured abstracts, analytical annotations, and data reports provided by SinoGreenTechare intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoGreenTech claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is the endurance and retention performance of the OS-channel FeFET under repeated program/erase cycles, and how does the Ta2O5 interlayer mitigate fatigue?
The research text does not provide explicit endurance or retention data. However, the Ta2O5 interlayer acts as an oxygen diffusion barrier, preventing interfacial reactions between HZO and IGZO, which is expected to reduce defect generation and improve cycling endurance. Further studies are needed to quantify endurance (e.g., >10^6 cycles) and retention (e.g., >10 years at 85°C) to meet NAND specifications.
How does the near-zero V_th and wide memory window translate into actual power savings at the array level, considering peripheral circuitry and parasitic capacitances?
The reduction of V_pass from 5–10 V to 1 V directly lowers the voltage swing on word lines, reducing dynamic power consumption (CV^2f) by a factor of 25–100. At the string level, this decreases read/write energy per bit. However, peripheral circuitry and parasitic capacitances may offset some gains; a full array-level analysis is required to quantify net power savings.
What are the scalability limitations of the OS-channel FeFET for 3D stacking beyond 1000 layers, particularly regarding deposition uniformity and thermal budget?
The IGZO channel and HZO ferroelectric layers are deposited at low temperatures (<400°C), compatible with 3D integration. However, achieving uniform thickness and composition across high-aspect-ratio vertical channels becomes challenging as layer count increases. The dual interlayers (SiO2/SiNx and Ta2O5) must be deposited conformally, and the thermal budget must be managed to avoid degradation of the ferroelectric properties. These factors will determine the maximum stack height.
How does the OS-channel FeFET compare to emerging alternatives like 3D DRAM or MRAM in terms of cost per bit and manufacturing complexity?
The OS-channel FeFET leverages existing CMOS-compatible materials (HZO, IGZO) and processes, potentially offering lower cost than MRAM, which requires magnetic materials and specialized deposition. Compared to 3D DRAM, it provides non-volatility, eliminating refresh power. However, the added complexity of ferroelectric deposition and dual interlayers may increase manufacturing cost. A detailed cost analysis is needed to assess competitiveness.
Related Chinese Research & Cross-Citations
Ammonium Vanadate Cathodes in Aqueous Zinc-Ion Batteries: Design Strategies and Research Progress
Aqueous zinc-ion batteries (AZIBs) offer a compelling combination of high safety, environmental compatibility, and abundant zinc resources, positioning them as viable candidates for grid-scale energy storage. Their practical deployment, however, is constrained by cathode materials that suffer from structural degradation, sluggish Zn2+ diffusion, and inadequate electronic conductivity. Ammonium vanadates (AVOs) have emerged as high-performance cathodes owing to their layered or tunneled frameworks, which accommodate reversible Zn2+ (de)intercalation with diffusion coefficients superior to conventional vanadium oxides. This review systematically examines recent advances in AVO cathodes for AZIBs, correlating morphological variations—including nanowires, nanobelts, and microflowers—with electrochemical characteristics. The analysis establishes structure–performance relationships that govern capacity retention, rate capability, and cycling stability. Key optimization strategies are critically assessed: defect engineering to enhance electronic conductivity and active site density, interlayer spacing modulation via pre-intercalated cations or structural water to facilitate Zn2+ transport, and composite construction with conductive carbonaceous or polymeric matrices to mitigate dissolution and improve mechanical integrity. Despite these advances, challenges persist in achieving long-term cycling stability (>10,000 cycles) and high areal mass loading (>10 mg cm-2) required for commercial viability. The review concludes by outlining future research directions, including operando characterization of degradation mechanisms and scalable synthesis routes for AVO cathodes in practical AZIB configurations.
Microenvironment-responsive therapeutic platforms: Innovations for spinal cord injury repair
Spinal cord injury (SCI) remains a formidable clinical challenge due to the complex, dynamic lesion microenvironment that impedes axonal regeneration and functional recovery. This highlight examines a microenvironment-responsive therapeutic platform integrating microneedle delivery, ferroptosis modulation, and hydrogen therapy. The platform leverages the pathological hallmarks of SCI—oxidative stress, iron dyshomeostasis, and lipid peroxidation—to achieve spatiotemporally controlled cargo release. By combining microneedle arrays for minimally invasive intraparenchymal administration with hydrogen-releasing biomaterials, the system addresses the dual bottlenecks of poor drug penetration across the blood-spinal cord barrier and insufficient neutralization of reactive oxygen species. Ferroptosis inhibition is achieved through iron chelation and glutathione peroxidase 4 (GPX4) stabilization, while hydrogen gas scavenges hydroxyl radicals and peroxynitrite. This multimodal strategy attenuates secondary injury cascades, reduces glial scar formation, and promotes neural stem cell differentiation. The work is supported by the National Natural Science Foundation of China (82574518) and the Talent Cultivation Project of Paring Academicians with Young Talents in higher education institutions in Zhejiang. The authors declare no conflict of interest. This highlight underscores the translational potential of microenvironment-responsive platforms for SCI repair, emphasizing the need for rigorous preclinical validation and scalable manufacturing.
Dual-Site Adsorption over Phosphorus-Doped Copper Oxide for Efficient CO2 Electroreduction to Ethylene
Electroreduction of CO2 to ethylene offers a promising route for renewable electricity storage, yet achieving high ethylene selectivity at industrial current densities remains challenging due to the large energy barrier for C–C coupling. Here, we report a “MOF-assisted in situ doping” strategy to introduce the oxophilic nonmetal phosphorus (P) into the copper oxide (CuO) lattice, constructing a localized Cu–P dual-site adsorption configuration for the key *OCCHO intermediate. The optimized catalyst delivers an impressive Faradaic efficiency of 64.6% for ethylene with a partial current density of 646 mA cm-2. Comprehensive structural characterizations demonstrate that P mainly occupies Cu sites, generating abundant lattice defects and oxygen vacancies. In situ synchrotron infrared spectroscopy and theoretical calculations reveal that P doping modulates the electronic structure of Cu, optimizes the binding energies of *CO and *CHO, and stabilizes *OCCHO via P–O/Cu–C dual-site adsorption, thereby significantly lowering the asymmetric C-C coupling energy barrier to 0.74 eV. This work highlights a dual-site microenvironment regulation strategy for CO2-to-ethylene electroreduction.
Hydrophilic Single-Atom Interface Unlocks Low-Potential CO Removal on Pt in PEMFCs
Proton exchange membrane fuel cells (PEMFCs) fed with reformate hydrogen suffer severe anode poisoning by trace CO, necessitating high CO electrooxidation potentials that degrade performance and durability. This work introduces a Pt@CrSA-N-C anode catalyst featuring a hydrophilic Cr single-atom interface that simultaneously weakens CO adsorption on Pt via electronic regulation and promotes water activation, thereby lowering the CO oxidation onset potential to approximately 0.13 V vs. RHE. The onset potential was determined by two independent methods: the first potential at which the background-corrected current exceeds 0 mA cm-2 during CO oxidation reaction tests in a three-electrode system, and the potential at which the forward scan current exceeds the N2 background current in CO-stripping voltammetry. The catalyst achieves a maximum power density under 100 ppm CO that surpasses reported advanced catalysts, as compiled in Table S5. Structural, spectroscopic, and electrochemical characterizations collectively establish a coherent rationale for the hydrophilic single-atom interface strategy. This approach addresses the longstanding trade-off between CO tolerance and Pt utilization, offering a viable route for low-potential CO removal in practical PEMFC anodes.
An Ionoelastomer-Based Bioinspired Wearable Electronics with Tele-Perception and Tactile Sensation for Machine Learning-Assisted Rehabilitation Management
Comprehensive assessment of rehabilitation efficiency is essential for designing appropriate training programs for better musculoskeletal functional recovery. Existing contact-receptor-dependent rehabilitation assessment systems mostly focus on assessing the restoration of muscle function by evaluating grip strength or joint flexion angle; however, parameters reflecting neuromuscular synergistic function are always overlooked. Herein, we develop an ionoelastomer-based soft artificial electroreceptor (SAER) that integrates tele-perception and tactile sensation to track the rehabilitation process, collecting signals related to approaching speed and grip strength sequentially. The SAER uses polyurethane ionoelastomer incorporated with quasi-solid conductive salt as the electric field receptor, and is integrated on a rehabilitation-training ball after assembly to establish an untethered detection device; this enables the remote capture of hand approaching parameter within a 9 cm range, followed by the quantification of grip strength when contacting and grasping. Furthermore, a data-driven assessment system is established by integrating machine learning, which accurately classifies rehabilitation efficiency into six levels; it supports for rehabilitation evaluation and training programs adjustment. Overall, the SAER-based rehabilitation management system establishes a paradigm that synergistically evaluating parameters corresponding to neuromuscular functional restoration and holds strong potential for home-based active rehabilitation for minimizing dependence on frequent clinical supervision.
Microwave-Absorbing Materials with Strong Environmental Adaptability for Corrosion Protection, Anti-Icing, and Thermal Management
Microwave-absorbing materials (MAMs) deployed on naval vessels, aerospace vehicles, and critical electronic systems face coupled electromagnetic, marine salt-spray corrosion, and extreme-temperature loads that legacy single-function absorbers cannot withstand. This review consolidates progress on three environmentally adaptive MAM classes: corrosion-protective, anti-icing, and thermal-management absorbers. The electromagnetic loss and impedance-matching fundamentals are first established, then the synergistic mechanisms, design strategies, and characterization protocols for each class are examined against representative material systems and their measured performance. The analysis identifies a shared design logic—multiscale hierarchical architecture, interfacial polarization engineering, and multifunctional phase integration—while distinguishing the divergent protection mechanisms: barrier and passivation effects for corrosion, surface-energy and latent-heat regulation for anti-icing, and phonon–electron transport decoupling for thermal management. Persistent bottlenecks include the trade-off between impedance matching and protective-layer density, the absence of standardized coupled-field test protocols, and the scarcity of long-term salt-spray and thermal-cycling durability data. Future directions are delineated: intelligent self-adaptive absorbers, multiphysics-coupled simulation frameworks, and environmentally benign multifunctional integration. The review provides a theoretical and technical basis for the design, construction, and engineering scale-up of next-generation high-performance absorbers for aerospace, electronic, and marine equipment.