Wafer-scale ultrathin and uniform van der Waals ferroelectric oxide.
Saved in:
| Title: | Wafer-scale ultrathin and uniform van der Waals ferroelectric oxide. |
|---|---|
| Authors: | Wu, Qinci (AUTHOR), Li, Zhongrui (AUTHOR), Han, Bingchen (AUTHOR), Sun, Weiyu (AUTHOR), Liu, Qinyun (AUTHOR), Xue, Chengyuan (AUTHOR), Bae, Hyeonhu (AUTHOR), Wang, Mengdi (AUTHOR), Fu, Boyang (AUTHOR), Qian, Jun (AUTHOR), Zhu, Yongchao (AUTHOR), Sun, Yu (AUTHOR), Feng, Tingkai (AUTHOR), Gao, Xin (AUTHOR), Cong, Xuzhong (AUTHOR), Liu, Wanqing (AUTHOR), Gao, Yunan (AUTHOR), Yan, Binghai (AUTHOR), Tan, Congwei (AUTHOR), Liu, Hongtao (AUTHOR) |
| Source: | Science. 1/29/2026, Vol. 391 Issue 6784, p1-9. 9p. |
| Subjects: | Ferroelectric devices, Bismuth selenide, Ferroelectric crystals, Permittivity, Nonvolatile memory, Intermolecular forces |
| Abstract: | Ferroelectrics have great potential for nonvolatile memory and next-generation electronics, but conventional ferroelectric oxide films generally suffer structural nonuniformity, interfacial depolarization, and performance degradation, particularly when downscaled to advanced technology nodes. We demonstrate uniform, wafer-scale synthesis and back-end-of-line–compatible integration of ultrathin van der Waals (vdW) high-dielectric constant ferroelectric oxide Bi2SeO5, retaining an optimal coercive field and robust ferroelectricity at monolayer thickness. Ultrathin vdW ferroelectric oxides formed atomically uniform interfaces with two-dimensional semiconductors and yielded ferroelectric field-effect transistor (FeFET) arrays with a low operating voltage (0.8 volts), exceptional cycling endurance (>1.5 × 1012 cycles), fast write speed (20 nanoseconds), high on/off ratio (106), 10-year retention, ultralow energy consumption (2.8 femtojoules per bit per square micrometer), and <5% device-to-device variation. Reconfigurable logic-in-memory circuits with these FeFETs function at supply voltages of <1 volt. Editor's summary: The ferroelectric oxide Bi2SeO5 has a high-dielectric constant that enables high-performance ferroelectric field-effect transistors (FeFETs). Wu et al. oxidized Bi2O2Se films grown on 10-centimeter sapphire substrates to form Bi2SeO5 films at temperatures compatible with chip fabrication (see the Perspective by Behera and Cheema). These films exhibited robust ferroelectricity at monolayer thickness. The FeFETs operating at 0.8 volts had an endurance greater than 1.5 × 1012 cycles and an ultralow energy consumption of 2.8 femtojoules per bit per square micrometer. —Phil Szuromi INTRODUCTION: Ferroelectric field-effect transistors (FeFETs) are promising candidates for next-generation embedded nonvolatile memories and computing-in-memory architectures. Wafer-scale production and scaling down the thickness of the ferroelectric layer is essential for achieving high-density and low-power devices. However, producing uniform ferroelectric materials at sub-5-nm dimensions across a wafer remains a major challenge, largely because of performance degradation at atomic scales and interface-induced depolarization effects. RATIONALE: Van der Waals (vdW) ferroelectrics present a potential solution. Benefiting from their dangling-bond–free and atomically smooth surfaces, they can maintain stable ferroelectricity even at atomically thin scales and integrate seamlessly with two-dimensional (2D) semiconductors. However, vdW ferroelectrics that simultaneously offer a high dielectric constant (κ), wide bandgaps, suitable coercive fields, and large remanent polarization remain scarce. Therefore, there is a clear and urgent need to realize wafer-scale production and seamless integration of ultrathin, uniform vdW ferroelectric films. RESULTS: We found that a new high-κ vdW ferroelectric oxide, bismuth selenite (α-phase Bi2SeO5) retains stable ferroelectricity down to monolayer thickness and is immune to depolarization fields. Furthermore, we demonstrated the wafer-scale uniform synthesis and back-end-of-line (BEOL)–compatible monolithic integration of ultrathin α-phase Bi2SeO5 by controllably oxidizing 2D semiconductor Bi2O2Se below 400°C. Unlike previous methods such as transfer techniques or atomic layer deposition, our approach enables the formation of Bi2SeO5-Bi2O2Se vdW heterostructures with atomically smooth and coherent interfaces through precise oxidation, avoiding reliability degradation caused by charge trapping and trap generation at defective interfaces. Wafer-scale fabrication and comprehensive characterization of 2D Bi2O2Se-Bi2SeO5 FeFETs confirm the exceptional uniformity and device performance, exhibiting <5% device-to-device variation, a high on/off ratio of >106, and a large memory window of up to 0.9 V at 1 V operation. Benefiting from the fatigue-resistant ferroelectricity of bismuth oxide (Bi2O2)–based ultrathin vdW structure and the high-quality native-oxide coherent interface, our FeFET demonstrated record-low 0.8-V operation with 20-ns write speed, achieving ultrahigh endurance that exceeded 1.5 × 1012 cycles, meeting the strict reliability requirements of edge computing and computing-in-memory architectures. CONCLUSION: We have established a wafer-scale and BEOL-compatible approach for the synthesis of uniform ultrathin vdW ferroelectric oxide and seamless integration of ferroelectric-semiconductor heterostructures. This effectively overcomes key limitations in conventional ferroelectric integration—such as critical thickness constraints, interface charge trapping, and poor large-area uniformity—enabling the realization of FeFETs with exceptional device-to-device consistency and high performance. We anticipate that this vdW ferroelectric platform holds great promise for addressing the intertwined challenges of scalability, reliability, and 3D integrability for post-Moore computing architectures. Wafer-scale 2D ferroelectric-semiconductor heterostructure and 2D FeFET.: (Left) The wafer-scale ferroelectric-semiconductor heterostructure, featuring a high-κ ferroelectric Bi2SeO5 layer integrated with a semiconducting Bi2O2Se layer. (Right) Schematic showing 2D Bi2SeO5-Bi2O2Se FeFET, which enables record-low 0.8 V operation and ultrahigh endurance that exceeds 1.5 × 1012 cycles. [ABSTRACT FROM AUTHOR] |
| Copyright of Science is the property of American Association for the Advancement of Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Psychology and Behavioral Sciences Collection |
|
Full text is not displayed to guests.
Login for full access.
|
|
| Abstract: | Ferroelectrics have great potential for nonvolatile memory and next-generation electronics, but conventional ferroelectric oxide films generally suffer structural nonuniformity, interfacial depolarization, and performance degradation, particularly when downscaled to advanced technology nodes. We demonstrate uniform, wafer-scale synthesis and back-end-of-line–compatible integration of ultrathin van der Waals (vdW) high-dielectric constant ferroelectric oxide Bi2SeO5, retaining an optimal coercive field and robust ferroelectricity at monolayer thickness. Ultrathin vdW ferroelectric oxides formed atomically uniform interfaces with two-dimensional semiconductors and yielded ferroelectric field-effect transistor (FeFET) arrays with a low operating voltage (0.8 volts), exceptional cycling endurance (>1.5 × 1012 cycles), fast write speed (20 nanoseconds), high on/off ratio (106), 10-year retention, ultralow energy consumption (2.8 femtojoules per bit per square micrometer), and <5% device-to-device variation. Reconfigurable logic-in-memory circuits with these FeFETs function at supply voltages of <1 volt. Editor's summary: The ferroelectric oxide Bi2SeO5 has a high-dielectric constant that enables high-performance ferroelectric field-effect transistors (FeFETs). Wu et al. oxidized Bi2O2Se films grown on 10-centimeter sapphire substrates to form Bi2SeO5 films at temperatures compatible with chip fabrication (see the Perspective by Behera and Cheema). These films exhibited robust ferroelectricity at monolayer thickness. The FeFETs operating at 0.8 volts had an endurance greater than 1.5 × 1012 cycles and an ultralow energy consumption of 2.8 femtojoules per bit per square micrometer. —Phil Szuromi INTRODUCTION: Ferroelectric field-effect transistors (FeFETs) are promising candidates for next-generation embedded nonvolatile memories and computing-in-memory architectures. Wafer-scale production and scaling down the thickness of the ferroelectric layer is essential for achieving high-density and low-power devices. However, producing uniform ferroelectric materials at sub-5-nm dimensions across a wafer remains a major challenge, largely because of performance degradation at atomic scales and interface-induced depolarization effects. RATIONALE: Van der Waals (vdW) ferroelectrics present a potential solution. Benefiting from their dangling-bond–free and atomically smooth surfaces, they can maintain stable ferroelectricity even at atomically thin scales and integrate seamlessly with two-dimensional (2D) semiconductors. However, vdW ferroelectrics that simultaneously offer a high dielectric constant (κ), wide bandgaps, suitable coercive fields, and large remanent polarization remain scarce. Therefore, there is a clear and urgent need to realize wafer-scale production and seamless integration of ultrathin, uniform vdW ferroelectric films. RESULTS: We found that a new high-κ vdW ferroelectric oxide, bismuth selenite (α-phase Bi2SeO5) retains stable ferroelectricity down to monolayer thickness and is immune to depolarization fields. Furthermore, we demonstrated the wafer-scale uniform synthesis and back-end-of-line (BEOL)–compatible monolithic integration of ultrathin α-phase Bi2SeO5 by controllably oxidizing 2D semiconductor Bi2O2Se below 400°C. Unlike previous methods such as transfer techniques or atomic layer deposition, our approach enables the formation of Bi2SeO5-Bi2O2Se vdW heterostructures with atomically smooth and coherent interfaces through precise oxidation, avoiding reliability degradation caused by charge trapping and trap generation at defective interfaces. Wafer-scale fabrication and comprehensive characterization of 2D Bi2O2Se-Bi2SeO5 FeFETs confirm the exceptional uniformity and device performance, exhibiting <5% device-to-device variation, a high on/off ratio of >106, and a large memory window of up to 0.9 V at 1 V operation. Benefiting from the fatigue-resistant ferroelectricity of bismuth oxide (Bi2O2)–based ultrathin vdW structure and the high-quality native-oxide coherent interface, our FeFET demonstrated record-low 0.8-V operation with 20-ns write speed, achieving ultrahigh endurance that exceeded 1.5 × 1012 cycles, meeting the strict reliability requirements of edge computing and computing-in-memory architectures. CONCLUSION: We have established a wafer-scale and BEOL-compatible approach for the synthesis of uniform ultrathin vdW ferroelectric oxide and seamless integration of ferroelectric-semiconductor heterostructures. This effectively overcomes key limitations in conventional ferroelectric integration—such as critical thickness constraints, interface charge trapping, and poor large-area uniformity—enabling the realization of FeFETs with exceptional device-to-device consistency and high performance. We anticipate that this vdW ferroelectric platform holds great promise for addressing the intertwined challenges of scalability, reliability, and 3D integrability for post-Moore computing architectures. Wafer-scale 2D ferroelectric-semiconductor heterostructure and 2D FeFET.: (Left) The wafer-scale ferroelectric-semiconductor heterostructure, featuring a high-κ ferroelectric Bi2SeO5 layer integrated with a semiconducting Bi2O2Se layer. (Right) Schematic showing 2D Bi2SeO5-Bi2O2Se FeFET, which enables record-low 0.8 V operation and ultrahigh endurance that exceeds 1.5 × 1012 cycles. [ABSTRACT FROM AUTHOR] |
|---|---|
| ISSN: | 00368075 |
| DOI: | 10.1126/science.adz1655 |
