An Investigation of HZO-Based n/p-FeFET Operation Mechanism and Improved Device Performance by the Electron Detrapping Mode

Kuk, Song‐Hyeon; Han, Seungmin; Kim, Bong Ho; Baek, Seung Hyub; Han, Jae‐Hoon; Kim, Sang Hyeon

doi:10.1109/ted.2022.3154687

Cited by 16 publications

(6 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It would be caused by charge trapping assisted polarization switching. As previously reported by Kuk et al , 37,49 the nFeFET can operate by only electron trapping/de-trapping without holes, which would be like this a-ITZO FeTFT case.…”

Section: Measurement Results and Discussionsupporting

confidence: 61%

“…Although the retention property shows degradation as the time increases from 10 s at this moment, our devices showed immediate read-after-program from 10 −3 s, which is typically very difficult to achieve in Si channel FeFETs due to the charge trapping associated with the interfacial layer between HZO and the channel. 37,49 Retention characteristics can be further improved by optimizing the ferroelectric gate stack of metal/HZO/a-ITZO.…”

Section: Measurement Results and Discussionmentioning

confidence: 99%

“…4(b) and (c). There is no significant interfacial between a-ITZO and Al2O3/polycrystalized HZO in the figures unlike HZO/Si interface [37]. This will lead to some advantages compared to Si FeFET as discussed later.…”

Section: Device Fabricationmentioning

confidence: 96%

“…First, a Cr (50 nm)/glass substrate was wet cleaned, followed by bottom Cr gate electrode formation. Then, nanolaminated Al2O3 (1 nm)/HZO (10 nm) was deposited by ALD [36,37] and patterned by photolithography. The Al2O3 capping layer was added to prevent inter-diffusion between the HZO and a-ITZO [32], pursuing a high-quality MOS interface predominantly to affect the endurance characteristics in the FeFETs.…”

Section: Device Fabricationmentioning

confidence: 99%

“…There is no significant interfacial layer between a-ITZO and Al 2 O 3 /poly-crystalized HZO in the figures unlike the HZO/Si interface. 37 This will lead to some advantages compared to a Si FeFET as will be discussed later. Significantly, a nano-laminated HZO structure was also observed in the STEM image.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Demonstration of programmable light intensity of a micro-LED with a Hf-based ferroelectric ITZO TFT for Mura-free displays

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Measurement Results and Discussionsupporting

confidence: 61%

Section: Measurement Results and Discussionmentioning

confidence: 99%

Section: Device Fabricationmentioning

confidence: 96%

Section: Device Fabricationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Demonstration of programmable light intensity of a micro-LED with a Hf-based ferroelectric ITZO TFT for Mura-free displays

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

Ferroelectric Transistors for Memory and Neuromorphic Device Applications

Kim

Lee

2023

Advanced Materials

View full text Add to dashboard Cite

Because a non-centrosymmetric crystal structure is mandatory for ferroelectric properties, very few materials are classified as ferroelectric. Historically, materials with complex crystal structures, such as BaTiO 3 (BTO), Pb[Zr x Ti 1−x ]O 3 (PZT), and Sr 2 Bi 2 TaO 9 (SBT), have been found to exhibit ferroelectricity. [5][6][7][8][9] Due to their spontaneous polarization, ferroelectric materials are diversely applied in memory devices, actuators, sensors, and energy storage. [1,2,[10][11][12][13] As the polarization state of ferroelectric materials can be regulated by an external electric field and the polarization is retained after the removal of the external electric field, such materials have the potential for applications involving high-performance non volatile memories. [9,14] However, some issues of conventional ferroelectric materials, such as high annealing temperatures, the requirement of noble electrode materials, and the diffusion of elements such as Pb complicate the integration of the previously reported ferroelectric materials into complementary metal-oxide semiconductors (CMOSs). [15][16][17][18] Furthermore, the large dielectric constants of perovskite-based ferroelectrics lead to high depolarization fields; [9,16] thus, the materials have short retention time and exhibit unstable polarization. [9] Additionally, the limited thickness scalability, complex etching process, and fatigue behaviors of perovskite-based ferroelectrics hinder the development of highly scaled ferroelectric devices. [9,18] Thus, semiconductor devices based on ferroelectric materials have limited commercial applications. Since the development of hafnia-based ferroelectrics, ferroelectric hafnia has attracted immense attention toward the development of semiconductor devices. [19][20][21] Compared to perovskite-based ferroelectric materials, hafnia-based ferroelectrics exhibit high scalability, and have high coercive electric fields (E c ) and low dielectric permittivity values, making them suitable for the fabrication of high-performance memory devices. [2,16,20,22] Additionally, hafnia is compatible with Si-based CMOS processes. Due to these advantages, hafnia-based ferroelectrics have been used in next-generation memory devices (such as ferroelectric capacitors, transistors, and tunnel junctions [FTJs]). [22][23][24][25][26] This paper reviews the recent findings and applications of hafnia-based ferroelectrics, highlighting the recent advances in ferroelectric transistors for next-generation memory and neuromorphic Ferroelectric materials have been intensively investigated for highperformance nonvolatile memory devices in the past decades, owing to their nonvolatile polarization characteristics. Ferroelectric memory devices are expected to exhibit lower power consumption and higher speed than conventional memory devices. However, non-complementary metal-oxidesemiconductor (CMOS) compatibility and degradation due to fatigue of traditional perovskite-based ferroelectric materials have hindered the development of high-density...

show abstract

Oxygen Scavenging in HfZrO_x‐Based n/p‐FeFETs for Switching Voltage Scaling and Endurance/Retention Improvement

Kim

Kuk

Kim

et al. 2023

Adv Elect Materials

Self Cite

View full text Add to dashboard Cite

the internet of things, big-data analysis, and machine learning are required. As one method to solve the issues, logic-inmemory (LiM) devices that combine the memory unit and the logic unit have been proposed, and the HfZrO x (HZO)-based ferroelectric field-effect transistor (FeFET) is one of the promising candidates for LiM devices because of its sufficient remanent polarization (P r ), low power, high speed, high scalability, and good compatibility with complementary metal-oxide-semiconductor technology. [1,2] However, when the HZO film is directly stacked on the Si substrate, an unintentional interfacial layer (IL) of SiO x is formed, resulting in a metal/ferroelectric film/insulator/semiconductor (MFIS) structure. The presence of IL causes several critical problems in ferroelectric behavior, inducing a significant amount of charge trapping, [3,4] causing a huge gate voltage (V g ) drop due to a lower dielectric constant (≈3.9), [5] and forming a strong depolarization field. [5,6] In particular, the interfacial charge trap density of ≈10 12 cm −2 is involved in breakdown and fatigue induced by charge trapping, [3,4] which causes issues of low endurance and read delay in FeFETs. [3,4,7] On the other hand, beneficial effects such as charge-assisted polarization [8] and leakage reduction [9] by IL are also exerted. Therefore, IL engineering to reduce thickness and unnecessary charge trapping is a promising direction in improving FeFET performances such as switching voltage (V sw ), memory window (MW), endurance, and retention properties.As attempts for IL engineering, methods such as the insertion of the additional IL, the modification by plasma treatment, and the inhibition of the IL formation have been reported. For the additional IL, Al 2 O 3 layers that can reduce leakage and improve endurance properties were explored, however, V sw increased due to an additional V g drop across the additional IL. [9] Alternatively, the insertion of ZrO 2 , which can improve the crystalline quality of the ferroelectric orthorhombic phase of HZO, improved P r and endurance property, but did not improve V sw . [10,11] Forming SiON by replacing SiO x was beneficial for endurance and retention properties, but a high-temperature process of 850 °C was required. [12] Treatment of IL with N 2 plasma improved endurance property only and had no effect on V sw . [13] In order to inhibit IL growth, microwave annealing, [14,15] The authors demonstrate improved switching voltage, retention, and endurance properties in HfZrO x (HZO)-based n/p-ferroelectric field-effect transistors (FeFETs) via oxygen scavenging. Oxygen scavenging using titanium (Ti) in the gate stack successfully reduce the thickness of interfacial oxide between HZO and Si and the oxygen vacancy at the bottom interface of the HZO film. The n/p-FeFETs with scavenging exhibit an immediate read-afterwrite with stable retention property and improved endurance property. In particular, n-FeFET with scavenging exhibits excellent endurance property that does not show breakdown up t...

show abstract

An Investigation of HZO-Based n/p-FeFET Operation Mechanism and Improved Device Performance by the Electron Detrapping Mode

Cited by 16 publications

References 18 publications

Demonstration of programmable light intensity of a micro-LED with a Hf-based ferroelectric ITZO TFT for Mura-free displays

Demonstration of programmable light intensity of a micro-LED with a Hf-based ferroelectric ITZO TFT for Mura-free displays

Ferroelectric Transistors for Memory and Neuromorphic Device Applications

Oxygen Scavenging in HfZrO_x‐Based n/p‐FeFETs for Switching Voltage Scaling and Endurance/Retention Improvement

Contact Info

Product

Resources

About

An Investigation of HZO-Based n/p-FeFET Operation Mechanism and Improved Device Performance by the Electron Detrapping Mode

Cited by 16 publications

References 18 publications

Demonstration of programmable light intensity of a micro-LED with a Hf-based ferroelectric ITZO TFT for Mura-free displays

Demonstration of programmable light intensity of a micro-LED with a Hf-based ferroelectric ITZO TFT for Mura-free displays

Ferroelectric Transistors for Memory and Neuromorphic Device Applications

Oxygen Scavenging in HfZrOx‐Based n/p‐FeFETs for Switching Voltage Scaling and Endurance/Retention Improvement

Contact Info

Product

Resources

About

Oxygen Scavenging in HfZrO_x‐Based n/p‐FeFETs for Switching Voltage Scaling and Endurance/Retention Improvement