Query: High breakdown voltage GNA buffer

Candidate papers:

abstract: This letter has studied the performance of AlGaN/GaN metal insulator semiconductor high electron mobility transistors on silicon substrate with GaN buffer treated by aluminum ion implantation for insulating followed by a channel regrown by metal organic chemical vapor deposition. For samples with Al ion implantation of multiple energies of 140 keV (dose: 1.4 x 1014 cm 2) and 90 keV (dose: 1 x 1014 cm 2) the OFF state leakage current is decreased by more than 3 orders and the breakdown voltage is enhanced by nearly 6 times compared to the samples without Al ion implantation. Besides, little degradation of electrical properties of the 2D electron gas channel is observed where the maximum drain current IDSmax at a gate voltage of 3 V was 701 mA/mm and the maximum transconductance gmmax was 83 mS/mm.
author_names: Shichuang Sun

Kai Fu

Guohao Yu

Zhang Zhili

Liang Song

Xuguang Deng

Zhiqiang Qi

Shuiming Li

Qian Sun

Yong Cai

Jiangnan Dai

Changqin Chen

Baoshun Zhang
title: AlGaN/GaN metal insulator semiconductor high electron mobility transistors with reduced leakage current and enhanced breakdown voltage using aluminum ion implantation
year: 2016

abstract: GaN power ICs on engineered substrates of Qromis substrate technology (QST) are promising for future power applications, thanks to the reduced parasitics, thermally matched substrate of poly AlN, high thermal conductivity, and high mechanical yield in combination with thick GaN buffer layers. In this article, we will elaborate in detail on epitaxy, integration, and trench isolation. Electrical characterizations show that the GaN buffer bears a breakdown voltage of 650 V under the leakage criterion of <inline formula> <tex math notation="LaTeX"$10~\mu \text{A} /tex math>/inline formula>/mm<sup>2</sup> at 150 degC. The fabricated 36 mm power HEMTs with <inline formula> <tex math notation="LaTeX"{L} _{\mathrm{ GD} /tex math>/inline formula> of <inline formula> <tex math notation="LaTeX"$16~\mu \text{m} /tex math>/inline formula> show a high threshold voltage of 3.1 V and a low OFF state drain leakage of <inline formula> <tex math notation="LaTeX" 1~\mu \text{A} /tex math>/inline formula>/mm until 650 V. The horizontal trench isolation breakdown voltage exceeds 850 V. The device dispersion is well controlled within 20% over full temperature and bias range. Finally, GaN power ICs on this platform are demonstrated.
author_names: Xiangdong Li

Karen Geens

Dirk Wellekens

Ming Zhao

Alessandro Magnani

Nooshin Amirifar

Benoit Bakeroot

Shuzhen You

Dirk Fahle

Herwig Hahn

Michael Heuken

Vladimir Odnoblyudov

Ozgur Aktas

Cem Basceri

Denis Marcon

Guido Groeseneken

Stefaan Decoutere
title: Integration of 650 V GaN Power ICs on 200 mm Engineered Substrates
venue: IEEE Transactions on Semiconductor Manufacturing
year: 2020

abstract: The aim of this work is to demonstrate high breakdown voltage and low buffer trapping in superlattice GaN on Silicon heterostructures for high voltage applications. To this aim, we compared two structures, one based on a step graded (SG) buffer (reference structure) and another based on a superlattice (SL) In particular, we show that: (i) the use of an SL allows us to push the vertical breakdown voltage above 1500 V on a 5 um stack, with a simultaneous decrease in vertical leakage current, as compared to the reference GaN based epi structure using a thicker buffer thickness. This is ascribed to the better strain relaxation, as confirmed by X Ray Diffraction data, and to a lower clustering of dislocations, as confirmed by Defect Selective Etching and Cathodoluminescence mappings. (ii) SL based samples have significantly lower buffer trapping, as confirmed by substrate ramp measurements. (iii) Backgating transient analysis indicated that traps are located below the two dimensional electron gas, and are related to CN defects. (iv) The signature of these traps is significantly reduced on devices with SL. This can be explained by the lower vertical leakage (filling of acceptors via electron injection) or by the slightly lower incorporation of C in the SL buffer, due to the slower growth process. SL based buffers therefore represent a viable solution for the fabrication of high voltage GaN transistors on silicon substrate, and for the simultaneous reduction of trapping processes.
author_names: Alaleh Tajalli

Matteo Meneghini

Sven Besendorfer

Riad Kabouche

Idriss Abid

Roland Pusche

Joff Derluyn

Stefan Degroote

Marianne Germain

Elke Meissner

Enrico Zanoni

Farid Medjdoub

Gaudenzio Meneghesso
title: High Breakdown Voltage and Low Buffer Trapping in Superlattice GaN on Silicon Heterostructures for High Voltage Applications
venue: Materials
year: 2020

abstract: We propose a novel GaN high breakdown voltage high electron mobility transistor (HB HEMT) with a p GaN gate and hybrid AlGaN buffer to improve the breakdown voltage and Baliga's figure of merit. The hybrid AlGaN buffer is composed of a horizontally arranged AlaGa1 aN zone and an AlbGa1 bN zone, each having different Al compositions a and b. The proposed HB HEMT is simulated using the Silvaco technology computer aided design (TCAD) tool ATLAS, considering the polarization model, low field mobility, high field mobility, and Selberherr's impact ionization model to simulate the direct current (DC) breakdown, and C V properties of the proposed HB HEMT. The breakdown voltage of the HB HEMT is significantly improved by introducing the hybrid AlGaN buffer structure, which can effectively modulate the electric field distributions within the channel and the buffer. A high breakdown voltage (1450 V) a low specific on state resistance (0.47 mO cm2) and a high Baliga's figure of merit (4.47 GW/cm2) are obtained at the same time with an Lgd (gate to drain distance) of 6 um, a distance from the gate to the AlaGa1 aN/AlbGa1 bN interface of 4 um, and Al compositions of a 0.25 and b 0.1. The simulated C V results also reveal that the GaN HB HEMT shows better switching characteristics than the conventional GaN HEMT with a p GaN gate.
author_names: Yang Liu

Qi Yu

Jiangfeng Du
title: Simulation design of a high breakdown voltage p GaN gate GaN HEMT with a hybrid AlGaN buffer layer for power electronics applications
year: 2020

author_names: Qi Yu

Jiangfeng Du
title: A novel high breakdown voltage and high switching speed GaN HEMT with p GaN gate and hybrid AlGaN buffer layer for power electronics applications
year: 2020

abstract: We have successfully grown AlGaN/GaN high electron mobility transistor (HEMT) structure on the high quality undoped thick AlN buffer layer with large band offset to replace the conventional high resistivity GaN buffer layer. The AlGaN/GaN HEMT fabricated on this AlN buffer layer exhibits low OFF state leakage current with high <inline formula> <tex math notation="LaTeX"{I}_{\mathrm{\scriptscriptstyle ON}{I}_{\mathrm{\scriptscriptstyle OFF} /tex math>/inline formula> of <inline formula> <tex math notation="LaTeX"\sim 10^{6} /tex math>/inline formula> due to enhanced confinement of the electrons in the 2 D electron gas (2 DEG) channel. The undoped AlN buffer layer is responsible for suppressing the trapping effects to greatly reduce the current dispersion in pulsed <inline formula> <tex math notation="LaTeX"{I}_{\text {D} /tex math>/inline formula> <inline formula> <tex math notation="LaTeX"{V}_{\text {D} /tex math>/inline formula> characteristics, which is hardly avoided in conventional deep acceptor doped GaN buffer layer. The device also demonstrates high breakdown voltage of 2154 V with very high figure of merit (FOM) of ~1.8 GV<inline formula> <tex math notation="LaTeX"{2 1} /tex math>/inline formula>cm<inline formula> <tex math notation="LaTeX" {2} /tex math>/inline formula> one of the highest ever reported, suggesting that the AlGaN/GaN based Hemts WITH AlN buffer layer are promising for high performance RF and power applications.
author_names: Jeong-Gil Kim

Chu-Young Cho

Eunjin Kim

Jae Seok Hwang

Jung-Hee Lee
title: High Breakdown Voltage and Low Current Dispersion in AlGaN/GaN HEMTs With High Quality AlN Buffer Layer
venue: IEEE Transactions on Electron Devices
year: 2021

author_names: Jung-Ran Lee
title: High Breakdown Voltage Low leakage Current AlGaN GaN HEMT with Peridodically C doped GaN Buffer and AlGaN Back Barrier
year: 2018

abstract: The relatively low breakdown voltage (BV) seriously restricts the high power application of GaN based high electron mobility transistors (HEMTs) In this work, a novel AlGaN/GaN HEMT with buried p n junctions is investigated to improve the breakdown characteristics by introducing six equidistant p GaN islands buried buffer layer (PIBL) into the n GaN epitaxial layer. The p GaN islands act as reversed p n junctions, which produces new electric field peaks at the edges of p GaN islands, then realizing a much high breakdown voltage, and the reversed p n junctions can help to suppress punch through effect in buffer layer. Furthermore, the characteristics of proposed device are analyzed in detail from the aspects of off state I V characteristics, equipotential contour distribution, off state electric field distribution, offstate carrier distribution and output characteristics. Simulated equipotential contour distribution shows that under the condition of high voltage blocking state, multiple reverse p n junctions introduced by the buried p GaN islands produce five new electric field peaks, realizing a more uniform equipotential contour distribution especially at the edges of the buried p islands. Then off state electric field distribution demonstrates that p GaN islands modulate the surface and bulk electric fields, which makes the voltage distributed in a larger area, therefore presenting a much higher breakdown voltage. It can be seen from off state carrier distribution that the electrons in the buffer layer fully depleted in PIBL HEMT effectively suppress the buffer leakage current, thus alleviating the buffer leakage induced impact ionization leading to a high breakdown BV of over 1700 V with gate to drain length of 10mm, which is nearly 3 times larger than BV of 580 V in conventional AlGaN/GaN HEMT. Although, the introduction of p type buried layer narrows the current path and causes an improved on resistance, simulation shows that the specific on resistance (Ron,sp) of PIBL HEMT is only about 1.47 mO*cm2, while the BV of the PIBL device is over 1700 V, and the obtained figure of merit (FOM=BV2/Ron,sp) reaches as high as 1966 MW*cm 2. The optimization of device structure reveals that when the distance between p GaN layer and AlGaN layer (t) is 0.2mm, a thinner buried p GaN island (tp) should help to realize a more significant electric field modulation, and PIBL HEMT can achieve a maximum BV of 1789 V with a tp=0.1mm. Compared with the traditional AlGaN/GaN HEMT, the PIBL HEMT reveals a higher breakdown voltage, meanwhile ensuring low Ron,sp, which makes this structure a promising candidate in the applications of high power electronic devices.
author_names: Zhang Li

Lin Zhi-Yu

Luo Jun

Wang Shu-long

Zhang Jin-cheng

Hao Yue

Dai Yang

Chen Da-Zheng

Guo Li-Xin
title: High breakdown voltage lateral AlGaN/GaN high electron mobility transistor with p GaN islands buried buffer layer for power applications
year: 2017

abstract: The ablation of high voltage cable buffer layer has puzzled the field of high voltage cable for nearly 20 years. It has been studied that the development process of this kind of fault is that the buffer layer of high voltage cable develops from whiteness, ablation to cable breakdown. More and more high voltage cable related personnel pay attention to such failures. With the development of research, the reason and mechanism of this kind of fault are gradually clear. Based on a typical case of ablation failure of buffer layer of high voltage cable, this paper analyzes the failure phenomenon and mechanism. It eliminates the possibility that the buffer belt may be affected by moisture due to the water breaking out of the cable. The resistivity and moisture content of the buffer belt of different cable sections are tested, and the gap between the buffer layer and the aluminum sheath is measured, which verifies the theoretical analysis results. It is found that the volume resistivity and water content are both higher than the existing standards. The results of this paper lay the foundation for the further study of this fault type.
author_names: Pengxian Song

Zhengzheng Meng

Xu Li

Mingzheng Zhu

Yang Yu

Shengchen Fang
title: A Case Study on Ablation Breakdown of High Voltage Cable Buffer Layer
venue: 2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)
year: 2020

author_names: Kazushige Horio

Yukihiro Kawada

R Tomita

Shingo Ueda
title: Analysis of Breakdown Voltage of AlGaN/GaN HEMTs with High k Passivation Layer and High Acceptor Density in Buffer Layer
year: 2019