The incorporation of AlScN ferroelectric gate dielectric in AlGaN/GaN-HEMT with polarization-modulated threshold voltage

Zhao, Zihui; Dai, Ying; Meng, Fanping; Chen, Li; Liu, Kunzi; Luo, Tian; Yu, Zhehan; Wang, Qikun; Yang, Zhenhai; Zhang, Jijun; Guo, Wei; Wu, Liang; Ye, Jichun

doi:10.35848/1882-0786/acbe26

Cited by 15 publications

(5 citation statements)

References 24 publications

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“…6,15 Knowing the correct polarity of the polarizations is very important for modeling polarization reversal in GaN-based heterostructures, such as ferroelectric high electron mobility transistors (FeHEMTs). [19][20][21][22] This is due to the fact that different polarities can result in the prediction of different signs of the interface sheet charges and, in consequence, in the sign of accumulated charge carriers that form the channel of the transistor.…”

Section: Modeling Of Polarization Reversal-induced Interface Sheet Ch...mentioning

confidence: 99%

Modeling of polarization reversal-induced interface sheet charge in wurtzite-type AlScN/GaN heterostructures

Yassine,

Nair

et al. 2024

Journal of Applied Physics

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In this work, the value and the polarity of the spontaneous and piezoelectric polarization have been investigated, as the use of two different reference structures for wurtzite-type group-III nitrides, namely, the zinc-blende and the layered-hexagonal crystal lattice, have resulted in different predictions. It was found that although the differences in value and polarity of the polarization for heterostructures such as wurtzite Al1−xScxN/GaN lead to similar interface sheet charges, a significant mismatch is observed when polarization reversal is considered. The interface sheet charge predicted before and after the polarization reversal in the wurtzite Al1−xScxN layer on GaN using the zinc-blende lattice as a reference predominantly shows a change in sign. When using the layered-hexagonal lattice as a reference, not only is the same polarity of the interface sheet charge maintained after polarization reversal, but it is even 30 times larger. In this case, the giant and positive spontaneous polarization values for metal-polar Al1−xScxN extracted from the ferroelectric switching, as well as the alignment of the piezoelectric polarization to it, were observed to be consistent with the predictions referenced to the layered-hexagonal lattice. Thus, it is concluded that the layered-hexagonal reference is not only more suitable for predicting the ferroelectric properties of wurtzite Al1−xScxN but should also be the correct reference when considering polarization reversal in heterostructures. If the significant increase in the interface sheet charge after polarization reversal is experimentally detected, it will allow the design and fabrication of novel devices for future high-frequency and power electronics applications.

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Section: Modeling Of Polarization Reversal-induced Interface Sheet Ch...mentioning

confidence: 99%

Modeling of polarization reversal-induced interface sheet charge in wurtzite-type AlScN/GaN heterostructures

Yassine,

Nair

et al. 2024

Journal of Applied Physics

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“…The directions of the electric dipoles are reorganized with ferroelectric domains well aligned with each other. When the 2DEG is partially depleted, the threshold voltage in HEMT will shift positive towards an enhancement-mode HEMT [161]. Following this idea, Zhu et al [162] reported a HEMT-PD incorporated with PZT/ZnO composite ferroelectric and realized UV responsivity larger than 110 W A −1 at 365 nm.…”

Section: Hemt Hybrid Uv-pdmentioning

confidence: 99%

Recent advances and prospects for a GaN-based hybrid type ultraviolet photodetector

Zhang,

Deng,

Xia

et al. 2024

Semicond. Sci. Technol.

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Solid-state UV photodetectors (PD) have received numerous attention because of the advantages of small size, absence of external cooling, high selectivity, and the ability to utilize the energy band structure semiconductor materials to achieve detection across various wavelengths. III-nitride thin films, as typical wide bandgap semiconductors with mature n-type and p-type doping capabilities, are ideal candidates for solid-state UV-PDs. However, a combination between III-nitride and other wide bandgap materials can either enrich the functionality of such devices such as spectrum-selective and broadband UV detection, or offers opportunities to enhance device performance, including high photoresponsivity, high external quantum efficiency, low dark current and fast response time. This topical review focuses on giving a thorough review of the III-nitride based hybrid-type UV photodetectors, their recent progress and future prospects. This review highlights different optical and electrical properties of various materials including GaN, Ga2O3, ZnO, perovskite etc. By carefully choosing the materials on two sides of the heterojunction and modulating the thickness and fermi levels and corresponding layers, p-i-n, Schottky, or MSM type photodetectors were successfully fabricated with outstanding device performances and novel spectral-selective properties. The advantages for future development of such hybrid-type PDs will be discussed, such as inherently formed p-n junction with large depletion region at the interface of two different materials, capability of bandgap engineering to tune the band offset of conduction band and valence band, thus enabling large barrier height for one type of carrier without influencing the other. The drawbacks in hybrid-type UV-PD due to poor interface quality and challenges in forming electrical contact in nanostructure hybrid UV-PD will also be discussed.

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“…[ 1,2 ] They are characterized by some of the largest spontaneous polarizations and coercive fields among ferroelectrics in general, extreme temperature stability, as well as compatibility to the major Si and GaN‐based semiconductor platforms. [ 3–7 ] The fact that the wurtzite‐type ferroelectrics share the same crystal structure and are most often III‐nitrides themselves offers the perspective of introducing novel heterostructures with a sort of native ferroelectricity to engineer novel GaN‐based devices. One of the first devices considered in this context is the ferroelectric high electron mobility transistor (FE‐HEMT), [ 5–8 ] which could ultimately allow reconfigurable normally‐off functionality in normally‐on devices.…”

Section: Introductionmentioning

confidence: 99%

“…[ 3–7 ] The fact that the wurtzite‐type ferroelectrics share the same crystal structure and are most often III‐nitrides themselves offers the perspective of introducing novel heterostructures with a sort of native ferroelectricity to engineer novel GaN‐based devices. One of the first devices considered in this context is the ferroelectric high electron mobility transistor (FE‐HEMT), [ 5–8 ] which could ultimately allow reconfigurable normally‐off functionality in normally‐on devices. Due to economic benefits like high yield and ease‐of‐operation as well as very good single crystal quality, metal organic chemical vapor deposition (MOCVD) is today the dominant method for III‐nitride‐based HEMT fabrication.…”

Section: Introductionmentioning

confidence: 99%

Demonstration and STEM Analysis of Ferroelectric Switching in MOCVD‐Grown Single Crystalline Al_0.85Sc_0.15N

Wolff,

Schönweger,

Streicher

et al. 2024

Advanced Physics Research

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Wurtzite‐type Al1−xScxN solid solutions grown by metal organic chemical vapor deposition are for the first time confirmed to be ferroelectric. The film with 230 nm thickness and x = 0.15 exhibits a coercive field of 5.5 MV cm−1 at a measurement frequency of 1.5 kHz. The single crystal quality and homogeneous chemical composition of the film are confirmed by X‐ray diffraction and spectroscopic methods such as time of flight secondary ion mass spectrometry. Annular bright field scanning transmission electron microscopy serves to prove the ferroelectric polarization inversion at the unit cell level. The single crystal quality further allows to image the large‐scale domain pattern of a wurtzite‐type ferroelectric for the first time, revealing a predominantly cone‐like domain shape along the c‐axis of the material. As in previous work, this again implies the presence of strong polarization discontinuities along this crystallographic axis, which can be suitable for current transport. The domains are separated by narrow domain walls, for which an upper thickness limit of 3 nm is deduced but which can potentially be atomically sharp. The authors are confident that these results will advance the commencement of the integration of wurtzite‐type ferroelectrics to GaN as well as generally III‐N‐based heterostructures and devices.

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The incorporation of AlScN ferroelectric gate dielectric in AlGaN/GaN-HEMT with polarization-modulated threshold voltage

Cited by 15 publications

References 24 publications

Modeling of polarization reversal-induced interface sheet charge in wurtzite-type AlScN/GaN heterostructures

Modeling of polarization reversal-induced interface sheet charge in wurtzite-type AlScN/GaN heterostructures

Recent advances and prospects for a GaN-based hybrid type ultraviolet photodetector

Demonstration and STEM Analysis of Ferroelectric Switching in MOCVD‐Grown Single Crystalline Al_0.85Sc_0.15N

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The incorporation of AlScN ferroelectric gate dielectric in AlGaN/GaN-HEMT with polarization-modulated threshold voltage

Cited by 15 publications

References 24 publications

Modeling of polarization reversal-induced interface sheet charge in wurtzite-type AlScN/GaN heterostructures

Modeling of polarization reversal-induced interface sheet charge in wurtzite-type AlScN/GaN heterostructures

Recent advances and prospects for a GaN-based hybrid type ultraviolet photodetector

Demonstration and STEM Analysis of Ferroelectric Switching in MOCVD‐Grown Single Crystalline Al0.85Sc0.15N

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Demonstration and STEM Analysis of Ferroelectric Switching in MOCVD‐Grown Single Crystalline Al_0.85Sc_0.15N