共查询到20条相似文献,搜索用时 15 毫秒
1.
M. Wolter P. Javorka A. Fox M. Marso H. Lüth P. Kordoš R. Carius A. Alam M. Heuken 《Journal of Electronic Materials》2002,31(12):1321-1324
Four different layer structures are used to study deep-level traps in AlGaN/GaN high-electron mobility transistors (HEMTs)
by photo-ionization spectroscopy. The structures grown on sapphire substrates by metal-organic chemical vapor deposition show
nearly identical Hall data. However, the direct current (DC) performance of HEMTs with identical geometry is found to differ
strongly. In all structures investigated, two distinct defect levels, namely, at 2.84–2.94 eV and 3.24–3.28 eV, were found
from the fits of the photo-ionization cross-sectional data. Additionally, different trap concentrations can be deduced. These
are in good correlation with the different transconductance and drain current measured. It is assumed that the defect levels
observed are related to the AlGaN surface. 相似文献
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本文论述了AlGaN/GaN双异质结高电子迁移率晶体管的特性,该结构使用Al组分为7%的AlGaN来代替传统的GaN作为缓冲层。Al0.07Ga0.93N缓冲层增加了二维电子气沟道下方的背势垒高度,有效提高了载流子限阈性,从而造成缓冲层漏电的显著减小以及击穿电压的明显提高。对于栅尺寸为0.5100μm,栅漏间距为1μm的器件,AlGaN/GaN 双异质结器件的击穿电压(~100V)是常规单异质结器件的两倍(~50V)。本文中的双异质结器件在漏压为35V、频率为4GHz下,最大输出功率为7.78W/mm,最大功率附加效率为62.3%,线性增益为23dB。 相似文献
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正We studied the performance of AlGaN/GaN double heterojunction high electron mobility transistors (DH-HEMTs) with an AlGaN buffer layer,which leads to a higher potential barrier at the backside of the twodimensional electron gas channel and better carrier confinement.This,remarkably,reduces the drain leakage current and improves the device breakdown voltage.The breakdown voltage of AlGaN/GaN double heterojunction HEMTs (~ 100 V) was significantly improved compared to that of conventional AlGaN/GaN HEMTs(~50 V) for the device with gate dimensions of 0.5 x 100μm and a gate-drain distance of 1μm.The DH-HEMTs also demonstrated a maximum output power of 7.78 W/mm,a maximum power-added efficiency of 62.3%and a linear gain of 23 dB at the drain supply voltage of 35 V at 4 GHz. 相似文献
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A novel AlGaN/GaN high electric mobility transistor(HEMT) with polyimide(PI)/chromium(Cr) as thepassivationlayerisproposedforenhancingbreakdownvoltageanditsDCperformanceisalsoinvestigated.The Cr nanoparticles firstly introduced in PI thin films by the co-evaporation can be used to increase the permittivity of PI film. The high-permittivity PI/Cr passivation acting as field plate can suppress the fringing electric field peak at the drain-side edge of the gate electrode. This mechanism is demonstrated in accord with measured results. The experimental results show that in comparison with the AlGaN/GaN HEMTs without passivation, the breakdown voltage of HEMTs with the PI/Cr composite thin films can be significantly improved, from 122 to 248 V. 相似文献
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B. Luo J. W. Johnson F. Ren K. K. Allums C. R. Abernathy S. J. Pearton R. Dwivedi T. N. Fogarty R. Wilkins A. M. Dabiran A. M. Wowchack C. J. Polley P. P. Chow A. G. Baca 《Journal of Electronic Materials》2002,31(5):437-441
AlGaN/GaN high-electron mobility transistors (HEMTs) show decreases in extrinsic transconductance, drain-source current threshold
voltage, and gate current as a result of irradiation with 40 MeV protons at doses equivalent to decades in low-earth orbit.
The data are consistent with the protons creating deep electron traps that increase the HEMT channel resistance. Postirradiation
annealing at 300°C was able to restore ∼70% of the initial gm and IDS values in HEMTs receiving proton doses of 5×1010 cm−2. 相似文献
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采用一个AlN缓冲层和两个Al组分阶变的AlGaN过渡层作为中间层,在76.2mm Si衬底上外延生长出1.7μm厚无裂纹AlGaN/GaN异质结材料,利用原子力显微镜、X射线衍射、Hall效应测量和CV测量等手段对材料的结构特性和电学性能进行了表征。材料表面平整光滑,晶体质量和电学性能良好,2DEG面密度为1.12×1013cm-2,迁移率为1 208cm2/(V.s)。由该材料研制的栅长为1μm的AlGaN/GaN HEMT器件,电流增益截止频率fT达到10.4GHz,这些结果表明组分阶变AlGaN过渡层技术可用于实现高性能Si基GaN HEMT。 相似文献
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Since it is naturally normally-off, the hybrid AlGaN/GaN MOS-HEMT has a tremendous potential for an advanced GaN-based power switch. An analytical model for the hybrid AlGaN/GaN HEMT on-resistance is presented in this paper. The methodology presented here can aid the designers to understand the physics and to electrically characterize the new generation of GaN based devices. The models proposed here can also easily be implemented in TCAD simulation packages where models for GaN devices are not mature. 相似文献
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F等离子体处理工艺被广泛的应用于 AlGaN/GaN HEMT增强型器件的研制和栅前处理工艺。本文研究了低功率F处理 AlGaN/GaN HEMT的击穿特性和电流崩塌特性。随着F处理时间的增加,饱和电流下降,阈值电压正向移动。对不同F处理时间的器件肖特基特性分析后发现,120s的F处理后器件栅泄漏电流明显减小,器件击穿电压提高,当F处理时间大于120s后,由于长时间F处理带来的损伤器件栅泄漏电流没有继续减小。采用不同偏置下的双脉冲测试对不同F处理时间的电流崩塌特性进行了研究,低功率F处理后没有发现明显的电流崩塌现象。 相似文献
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《Microelectronics Reliability》2014,54(11):2406-2409
Off-state breakdown characteristics of AlGaN/GaN high-electron-mobility transistors have been studied based on drain current injection method. It is found that at low drain current injection level, the observed premature breakdown is caused by excess gate-to-drain leakage current. Nevertheless, at high drain injection current level, buffer-leakage-dominated breakdown proceeds gate-leakage-dominated breakdown as the gate bias increases from pinch-off voltage to deep-depletion voltage. In both breakdown regions, the breakdown voltages show negative temperature coefficients. The buffer-leakage-induced breakdown should be defect-related, which is confirmed by temperature-dependent buffer leakage measurements. 相似文献
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Pu Yan Wang Liang Yuan Tingting Ouyang Sihua Pang Lei Liu Guoguo Luo Weijun Liu Xinyu 《半导体学报》2010,31(10)
The method of multi-bias capacitance voltage measurement is presented. The physical meaning of gate-source and gate-drain capacitances in AlGaN/GaN HEMT and the variations in them with different bias con-ditions are discussed. A capacitance model is proposed to reflect the behaviors of the gate-source and gate-drain ca-pacitances, which shows a good agreement with the measured capacitances, and the power performance obtains good results compared with the measured data from the capacitance model. 相似文献
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研究了在AlGaN/GaN高电子迁移率晶体管的栅极施加阶梯电压应力之后器件参数和特性的自变化现象。在去除应力之后每5分钟测量一次器件。大信号寄生源(漏)电阻、转移特性、阈值电压、漏源电流、栅-源(漏)反向电流-电压特性在去除应力后发生自发变化。自变化的时间常数大约为25-27分钟。在该过程里,栅-源(漏)电容-电压特性保持稳定。当器件被施加应力时,电子被表面态和AlGaN势垒层陷阱捕获。AlGaN势垒层陷阱所捕获的电子在10秒内释放了出去。表面态释放电子持续发生在整个测量过程中,导致了测量结果的自变化现象。 相似文献
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为了进一步提升P-GaN栅HEMT器件的阈值电压和击穿电压,提出了一种具有P-GaN栅结合混合掺杂帽层结构的氮化镓高电子迁移率晶体管(HEMT)。新器件利用混合掺杂帽层结构,调节整体极化效应,可以进一步耗尽混合帽层下方沟道区域的二维电子气,提升阈值电压。在反向阻断状态下,混合帽层可以调节栅极右侧电场分布,改善栅边电场集中现象,提高器件的击穿电压。利用Sentaurus TCAD进行仿真,对比普通P-GaN栅增强型器件,结果显示,新型结构器件击穿电压由593 V提升至733 V,增幅达24%,阈值电压由0.509 V提升至1.323 V。 相似文献
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Correlation of device performance and defects in AlGaN/GaN high-electron mobility transistors 总被引:2,自引:0,他引:2
A. P. Zhang L. B. Rowland E. B. Kaminsky V. Tilak J. C. Grande J. Teetsov A. Vertiatchikh L. F. Eastman 《Journal of Electronic Materials》2003,32(5):388-394
Device performance and defects in AlGaN/GaN high-electron mobility transistors (HEMTs) have been correlated. Surface depressions
and threading dislocations, revealed by optical-defect mapping and atomic force microscopy (AFM), compromised the effectiveness
of the SiNx surface-passivation effect as evidenced by the gate-lag measurements. The residual carriers in the GaN-buffer layer observed
from the capacitance-voltage depth profile have been attributed to the point defects and threading dislocations either acting
as donors or causing local charge accumulations. Deep-level transient-spectroscopy measurements showed the existence of several
traps corresponding to surface states and bulk-dislocation defects. The formation of electron-accumulation regions on the
surface or (and) in the GaN-buffer layer was confirmed by currentvoltage measurements. This second, virtual gate formed by
electron accumulations can deplete the channel and cause a large-signal gain collapse leading to degraded output power. A
good correlation was established between the device performance and defects in AlGaN/GaN HEMT structure. 相似文献