Modulation of VO<sub>2</sub> Metal–Insulator Transition by Ferroelectric HfO<sub>2</sub> Gate Insulator

Yajima, Takeaki; Nishimura, Tomonori; Tanaka, Takahisa; Uchida, Ken; Toriumi, Akira

doi:10.1002/aelm.201901356

Cited by 15 publications

(13 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, the impact of the electric field on the resistivity of insulating state is also expected to be minimal 22 . This can be attributed to the formation of small polarons that result from the gate-induced charge coupling to the lattice, as shown in our prior work 23 , as well as in other works 24 . These polarons screen the electric field, and subsequently, limit its penetration to a few (1–2) monolayers, resulting in minimal effect on the conductivity.…”

supporting

confidence: 70%

A three-terminal non-volatile ferroelectric switch with an insulator–metal transition channel

Vaidya

Kanthi

Alam

et al. 2022

Sci Rep

View full text Add to dashboard Cite

Ferroelectrics offer a promising material platform to realize energy-efficient non-volatile memory technology with the FeFET-based implementations being one of the most area-efficient ferroelectric memory architectures. However, the FeFET operation entails a fundamental trade-off between the read and the program operations. To overcome this trade-off, we propose in this work, a novel device concept, Mott-FeFET, that aims to replace the Silicon channel of the FeFET with VO2- a material that exhibits an electrically driven insulator–metal phase transition. The Mott-FeFET design, which demonstrates a (ferroelectric) polarization-dependent threshold voltage, enables the read current distinguishability (i.e., the ratio of current sensed when the Mott-FeFET is in state 1 and 0, respectively) to be independent of the program voltage. This enables the device to be programmed at low voltages without affecting the ability to sense/read the state of the device. Our work provides a pathway to realize low-voltage and energy-efficient non-volatile memory solutions.

show abstract

supporting

confidence: 70%

A three-terminal non-volatile ferroelectric switch with an insulator–metal transition channel

Vaidya

Kanthi

Alam

et al. 2022

Sci Rep

View full text Add to dashboard Cite

show abstract

“…[11] As an archetypal Mott material, vanadium dioxide (VO 2 ) has a first-order metal-insulator transition above room temperature. [25][26][27][28] It has outstanding characteristics including fast switching speeds, high reliability, excellent nonvolatility, and scalability as good as other phase-change materials. [29,30] Compared to other phase-change materials, VO 2 has a variety of existing phases, [31,32] whose formation energies are similar.…”

Section: Introductionmentioning

confidence: 99%

Flexible VO₂ Films for In‐Sensor Computing with Ultraviolet Light

Xie

Zhang

et al. 2022

Adv Funct Materials

View full text Add to dashboard Cite

With their unique advantages in portability, shape adaptability, and human friendly surfaces, flexible electronics pave the way for the implementation of wearable electronic textiles and human-machine interfaces. Although organic materials are promising for flexible devices because of the low-cost manufacturing and inherent flexibility, they meet challenges in harsh environments such as ultraviolet (UV) irradiation, which limits their applicability in UV sensors. Here, a flexible UV neuromorphic sensor is presented using inorganic vanadium dioxide (VO 2 ) films grown on mica substrates. The flexible device shows UV photoinduced nonvolatile phase transition, and can be reversibly modulated using electrolyte gating. The optical responses remain almost unchanged after 10 000 bending cycles or at small bending radius, exhibiting high tolerance to the bending deformation. Besides, the variations in image recognition accuracy under different bending conditions keep within 1.6%, indicating that the device can be adapted to various deformation conditions. By constructing near-/in-sensor computing architectures using the flexible VO 2 neuromorphic sensors with photoinduced nonvolatile phase transition, both static image processing and motion detection are realized without redundant and massive information transfer. This result lays the foundation for the development of flexible UV neuromorphic sensors.

show abstract

“…More than that, NVM performance can be further enhanced by the Coatings 2022, 12, 348 2 of 12 cumulative contribution of the ferroelectric HfO 2 matrix besides that of Ge QDs charge storage centers [19]. By using a channel with Ge:HfO 2 gate, ferroelectric gating of the metal-insulator transition in ultra-thin VO 2 was also successfully demonstrated [20]. Using HfO 2 instead of classical SiO 2 in NVMs enables a lower oxide equivalent thickness, also ensuring higher charge retention, lower operating voltages, and large memory windows [21].…”

Section: Introductionmentioning

confidence: 99%

SiGeSn Quantum Dots in HfO2 for Floating Gate Memory Capacitors

et al. 2022

View full text Add to dashboard Cite

Group IV quantum dots (QDs) in HfO2 are attractive for non-volatile memories (NVMs) due to complementary metal-oxide semiconductor (CMOS) compatibility. Besides the role of charge storage centers, SiGeSn QDs have the advantage of a low thermal budget for formation, because Sn presence decreases crystallization temperature, while Si ensures higher thermal stability. In this paper, we prepare MOS capacitors based on 3-layer stacks of gate HfO2/floating gate of SiGeSn QDs in HfO2/tunnel HfO2/p-Si obtained by magnetron sputtering deposition followed by rapid thermal annealing (RTA) for nanocrystallization. Crystalline structure, morphology, and composition studies by cross-section transmission electron microscopy and X-ray diffraction correlated with Raman spectroscopy and C–V measurements are carried out for understanding RTA temperature effects on charge storage behavior. 3-layer morphology and Sn content trends with RTA temperature are explained by the strongly temperature-dependent Sn segregation and diffusion processes. We show that the memory properties measured on Al/3-layer stack/p-Si/Al capacitors are controlled by SiGeSn-related trapping states (deep electronic levels) and low-ordering clusters for RTA at 325–450 °C, and by crystalline SiGeSn QDs for 520 and 530 °C RTA. Specific to the structures annealed at 520 and 530 °C is the formation of two kinds of crystalline SiGeSn QDs, i.e., QDs with low Sn content (2 at.%) that are positioned inside the floating gate, and QDs with high Sn content (up to 12.5 at.%) located at the interface of floating gate with adjacent HfO2 layers. The presence of Sn in the SiGe intermediate layer decreases the SiGe crystallization temperature and induces the easier crystallization of the diamond structure in comparison with 3-layer stacks with Ge-HfO2 intermediate layer. High frequency-independent memory windows of 3–4 V and stored electron densities of 1–2 × 1013 electrons/cm2 are achieved.

show abstract

Modulation of VO₂ Metal–Insulator Transition by Ferroelectric HfO₂ Gate Insulator

Cited by 15 publications

References 30 publications

A three-terminal non-volatile ferroelectric switch with an insulator–metal transition channel

A three-terminal non-volatile ferroelectric switch with an insulator–metal transition channel

Flexible VO₂ Films for In‐Sensor Computing with Ultraviolet Light

SiGeSn Quantum Dots in HfO2 for Floating Gate Memory Capacitors

Contact Info

Product

Resources

About

Modulation of VO2 Metal–Insulator Transition by Ferroelectric HfO2 Gate Insulator

Cited by 15 publications

References 30 publications

A three-terminal non-volatile ferroelectric switch with an insulator–metal transition channel

A three-terminal non-volatile ferroelectric switch with an insulator–metal transition channel

Flexible VO2 Films for In‐Sensor Computing with Ultraviolet Light

SiGeSn Quantum Dots in HfO2 for Floating Gate Memory Capacitors

Contact Info

Product

Resources

About

Modulation of VO₂ Metal–Insulator Transition by Ferroelectric HfO₂ Gate Insulator

Flexible VO₂ Films for In‐Sensor Computing with Ultraviolet Light