Gate structure dependent normally-off AlGaN/GaN heterostructure field-effect transistors with p-GaN cap layer

Pu, Taofei; Chen, Yong; Li, Xiaobo; Peng, Tao-Wei; Wang, Xiao; Li, Jian; He, Wei; Ben, Jianwei; Lu, Youming; Liu, Xinke; Ao, Jin‐Ping

doi:10.1088/1361-6463/ab91ee

Cited by 6 publications

(5 citation statements)

References 24 publications

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“…Another method that is capable of effectively improving the gate voltage of a p-GaN HEMT device is to grow a passivation layer on it. Pu et al grew a SiN passivation layer on a p-GaN layer [ 30 , 31 ], the structural diagram of which is shown in Figure 11 . This approach combines the gate metal, passivation layer, and p-GaN of the device together to form an MIS structure, which greatly reduces the trapped surface charges of the device, thereby mitigating the gate-leakage current.…”

Section: Research Progressmentioning

confidence: 99%

Review on Main Gate Characteristics of P-Type GaN Gate High-Electron-Mobility Transistors

Wang,

Nan,

Tian

et al. 2023

Micromachines

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As wide bandgap semiconductors, gallium nitride (GaN) lateral high-electron-mobility transistors (HEMTs) possess high breakdown voltage, low resistance and high frequency performance. PGaN gate HEMTs are promising candidates for high-voltage, high-power applications due to the normally off operation and robust gate reliability. However, the threshold and gate-breakdown voltages are relatively low compared with Si-based and SiC-based power MOSFETs. The epitaxial layers and device structures were optimized to enhance the main characteristics of pGaN HEMTs. In this work, various methods to improve threshold and gate-breakdown voltages are presented, such as the top-layer optimization of the pGaN cap, hole-concentration enhancement, the low-work-function gate electrode, and the MIS-type pGaN gate. The discussion of the main gate characteristic enhancement of p-type GaN gate HEMTs would accelerate the development of GaN power electronics to some extent.

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Section: Research Progressmentioning

confidence: 99%

Review on Main Gate Characteristics of P-Type GaN Gate High-Electron-Mobility Transistors

Wang,

Nan,

Tian

et al. 2023

Micromachines

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“…Because the leakage current of the gate is caused by a tunneling phenomenon that is very sensitive to the barrier layer thickness and uniformity, this approach necessitates a perfect control of the AlGaN etching process. Furthermore, etching-induced damage might increase the leakage current of the gate and non-uniformity effects in VTH [91]. Additionally, there are two types of gates recessed available such as the slight MIS-HEMT of the recessed-gate design underneath the gate dielectric, a thin AlGaN barrier, and the complete MIS-FET of the recessed-gate design, known as a MOS-HFET hybrid, as shown in Figure 23a Standard MIS-FETs may obtain an E-mode performance by entirely eliminating the AlGaN barrier layer underneath the gate, resulting in the device turning off at a zero gate voltage.…”

Section: Hemts With P-gan Gate (Normally Off)mentioning

confidence: 99%

Reliability, Applications and Challenges of GaN HEMT Technology for Modern Power Devices: A Review

et al. 2022

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A new generation of high-efficiency power devices is being developed using wide bandgap (WBG) semiconductors, like GaN and SiC, which are emerging as attractive alternatives to silicon. The recent interest in GaN has been piqued by its excellent material characteristics, including its high critical electric field, high saturation velocity, high electron mobility, and outstanding thermal stability. Therefore, the superior performance is represented by GaN-based high electron mobility transistor (HEMT) devices. They can perform at higher currents, voltages, temperatures, and frequencies, making them suitable devices for the next generation of high-efficiency power converter applications, including electric vehicles, phone chargers, renewable energy, and data centers. Thus, this review article will provide a basic overview of the various technological and scientific elements of the current GaN HEMTs technology. First, the present advancements in the GaN market and its primary application areas are briefly summarized. After that, the GaN is compared with other devices, and the GaN HEMT device’s operational material properties with different heterostructures are discussed. Then, the normally-off GaN HEMT technology with their different types are considered, especially on the recessed gate metal insulator semiconductor high electron mobility transistor (MISHEMT) and p-GaN. Hereafter, this review also discusses the reliability concerns of the GaN HEMT which are caused by trap effects like a drain, gate lag, and current collapse with numerous types of degradation. Eventually, the breakdown voltage of the GaN HEMT with some challenges has been studied.

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“…Then, p-GaN at non-gate region was removed by a low damage recipe with ICP/bias of 100/20 W and SiCl 4 etching gas. [8] Before the deposition of ohmic metal, a ICP plasma treatment was carried out on the ohmic region to realize the low temperature annealing process. The recipe was ICP/bias 100/100 W at 0.5 Pa for 12 s. Ti/Al/Ti/Au (20/200/40/40 nm) ohmic metal stacks were then deposited by magnetron sputtering and annealed at 500 • C for 20 min in N 2 ambient.…”

Section: Device Structure and Fabricationmentioning

confidence: 99%

“…[5] In terms of realizing normally-off operation, the p-GaN cap layer structure demonstrates tremendous advantages such as high channel mobility, good V th uniformity and suitable for integration. [6][7][8][9][10][11] Based on those advantages, the AlGaN/GaN HFETs with p-GaN cap layer become the unique commercial solution to achieve the normally-off operation with respect to gate recess, fluorine ion treatment, ultrathin barrier, and so on. [12,13] On the basis of simulation and experiment results, the V th of p-GaN HFET presents a relationship with the contact type between the gate electrode and p-GaN.…”

Section: Introductionmentioning

confidence: 99%

“…Usually, the ohmic type gate can be formed by depositing and/or oxidizing Ni, NiO x , or Pt on p-GaN layer. [7,8] However, due to the low hole concentration in p-GaN, the V th is usually limited to around 1 V. Furthermore, the p-GaN/n-GaN junction turns on at a relatively small forward bias, leading to the huge gate leakage current. [14,15] Then, the Schottky type gate formed by a low work function metal on p-GaN is proposed to raise the V th to approximately 2 V and suppress the gate leakage current.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Normally-off AlGaN/GaN heterojunction field-effect transistors with in-situ AlN gate insulator

Pu¹,

Li²,

Wang³

et al. 2022

Chinese Phys. B

Self Cite

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In this study, AlGaN/GaN heterojunction field-effect transistors (HFETs) with p-GaN cap layer are developed for normally-off operation, in which an in-situ grown AlN layer is utilized as gate insulator. Compared with the SiNx gate insulator, the AlN/p-GaN interface presents a more obvious energy band bending and a wider depletion region, which helps to positively shift the threshold voltage. In addition, the relatively large conduction band offset of AlN/p-GaN is beneficial to suppress the gate leakage current and enhance the gate breakdown voltage. Owing to the introduction of AlN layer, normally-off p-GaN capped AlGaN/GaN HFET with a threshold voltage of 4 V and a gate swing of 13 V is realized. Furthermore, the field-effect mobility is approximately 1500 cm2V-1s-1 in 2DEG channel, implying the good device performance.

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Gate structure dependent normally-off AlGaN/GaN heterostructure field-effect transistors with p-GaN cap layer

Cited by 6 publications

References 24 publications

Review on Main Gate Characteristics of P-Type GaN Gate High-Electron-Mobility Transistors

Review on Main Gate Characteristics of P-Type GaN Gate High-Electron-Mobility Transistors

Reliability, Applications and Challenges of GaN HEMT Technology for Modern Power Devices: A Review

Normally-off AlGaN/GaN heterojunction field-effect transistors with in-situ AlN gate insulator

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