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用MOCVD技术在高阻6H-SiC衬底上研制出了具有高迁移率GaN沟道层的AlGaN/AlN/GaN高电子迁移率晶体管(HEMT)结构材料,其室温和80K时二维电子气迁移率分别为1944和11588cm2/(V·s),相应二维电子气浓度为1.03×1013cm-2;三晶X射线衍射和原子力显微镜分析表明该材料具有良好的晶体质量和表面形貌,10μm×10μm样品的表面粗糙度为0.27nm.用此材料研制出了栅长为0.8μm,栅宽为1.2mm的HEMT器件,最大漏极饱和电流密度和非本征跨导分别为957mA/mm和267mS/mm. 相似文献
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介绍了一种采用磁控溅射AlN介质作为绝缘层的的SiC衬底AlGaN/GaN MIS-HEMT.器件研制中采用了凹槽栅和场板结构.采用MIS结构后,器件击穿电压由80 V提高到了180 V以上,保证了器件能够实现更高的工作电压.在2 GHz、75 V工作电压下,研制的200μm栅宽AlGaN/GaNMIS-HEMT输出功率密度达到了14.4 W/mm,器件功率增益和功率附加效率分别为20.51 dB和54.2%. 相似文献
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研究了低温(LT) GaN和AlN不同插入层对抑制Mg掺杂p-GaN金属有机化学气相沉积外延中存在的记忆效应的影响,外延生长p-GaN缓冲层,制作具有该缓冲层的AlGaN/GaN高电子迁移率晶体管(HEMT),并对该器件进行电学测试.二次离子质谱仪测试表明p-GaN上10 nm厚的LT-GaN插入层相比于2 nm厚的AlN插入层能更好地抑制Mg扩散.霍尔测试表明,2 nm厚的AlN插入层的引入和GaN存在较大的晶格失配会引入位错,进而会降低AlGaN/GaNHEMT的电子迁移率以及增加其方块电阻;含有10 nm厚的LT-GaN插入层的p-GaN作为缓冲层的AlGaN/GaN HEMT,其方块电阻、电子迁移率以及二维电子气(2DEG)密度分别为334.9 Ω/口,1 923 cm2/(V·s)和9.68×1012 cm-2.器件具有很好的直流特性,其饱和电流为470 mA/mm,峰值跨导为57.7 mS/mm,电流开关比为3.13×109. 相似文献
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正The fabrication of AlGaN/GaN double-channel high electron mobility transistors on sapphire substrates is reported.Two carrier channels are formed in an AlGaN/GaN/AlGaN/GaN multilayer structure.The DC performance of the resulting double-channel HEMT shows a wider high transconductance region compared with single-channel HEMT. Simulations provide an explanation for the influence of the double-channel on the high transconductance region.The buffer trap is suggested to be related to the wide region of high transconductance.The RF characteristics are also studied. 相似文献
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The fabrication of AlGaN/GaN double-channel high electron mobility transistors on sapphire substrates is reported. Two carrier channels are formed in an AlGaN/GaN/AlGaN/GaN multilayer structure. The DC performance of the resulting double-channel HEMT shows a wider high transconductance region compared with single-channel HEMT. Simulations provide an explanation for the influence of the double-channel on the high transconductance region. The buffer trap is suggested to be related to the wide region of high transconductance. The RF characteristics are also studied. 相似文献
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The authors observed that a trace of water vapour can have a significant degradation effect on Ohmic contact formation for AlGaN/GaN high electron mobility transistors (HEMTs). The degradation effect due to a trace of water vapour is less serious for n-GaN. This is a more serious problem for AlGaN/GaN HEMT than AlGaAs/GaAs HEMT or InP based HEMT because of the higher temperature needed for Ohmic contact annealing when AlGaN or GaN are involved. Using cooling water with a temperature slightly higher than the ambient temperature during rapid thermal annealing (RTA) appears to be the best approach. 相似文献
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使用金属有机物化学气相淀积(MOCVD)方法在蓝宝石衬底上分别采用AlN和GaN作为形核层生长了AlGaN/GaN高电子迁移率晶体管(HEMT)外延材料,并进行了器件制备和性能分析.通过原子力显微镜(AFM)、高分辨率X射线双晶衍射仪(HR-XRD)和二次离子质谱仪(SIMS)等仪器对两种样品进行了对比分析,结果表明采用AlN形核层的GaN外延材料具有更低的位错密度,且缓冲层中氧元素的拖尾现象得到有效地抑制.器件直流特性显示,与基于GaN形核层的器件相比,基于AlN形核层的器件泄漏电流低3个数量级.脉冲Ⅰ-Ⅴ测试发现基于GaN形核层的HEMT器件受缓冲层陷阱影响较大,而基于AlN形核层的HEMT器件缓冲层陷阱作用不明显. 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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在8英寸(1英寸=2.54 cm)的Si衬底上采用金属有机化学气相沉积(MOCVD)生长了高质量、无龟裂的GaN薄膜和AlGaN/GaN高电子迁移率晶体管(HEMT)结构.通过调节应力调控层的结构,厚度为5 μm的GaN膜层翘曲度低于50 μm.采用X射线衍射(XRD)对GaN薄膜的(002)和(102)衍射峰进行扫描,其半峰全宽(FWHM)分别为182和291 arcsec.透射电子显微镜(TEM)截面图显示GaN外延层的位错密度达到了3.5×107/cm2,证实了在大尺寸Si衬底上可以制作高质量的GaN薄膜.AlGaN/GaN HEMT结构的二维电子气浓度和载流子迁移率分别为9.29×1012/cm2和2 230 cm2/(V·s).基于这些半绝缘AlGaN/GaNHEMT结构所制作的功率电子器件的输出电流可达20 A,横向击穿电压可达1 200 V. 相似文献
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AlGaN/AlN/GaN high-power microwave HEMT 总被引:2,自引:0,他引:2
Shen L. Heikman S. Moran B. Coffie R. Zhang N.-Q. Buttari D. Smorchkova I.P. Keller S. DenBaars S.P. Mishra U.K. 《Electron Device Letters, IEEE》2001,22(10):457-459
In this letter, a novel heterojunction AlGaN/AlN/GaN high-electron mobility transistor (HEMT) is discussed. Contrary to normal HEMTs, the insertion of the very thin AlN interfacial layer (~1 nm) maintains high mobility at high sheet charge densities by increasing the effective ΔEC and decreasing alloy scattering. Devices based on this structure exhibited good DC and RF performance. A high peak current 1 A/mm at VGS=2 V was obtained and an output power density of 8.4 W/mm with a power added efficiency of 28% at 8 GHz was achieved 相似文献
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S. K. Islam 《International Journal of Electronics》2013,100(12):1099-1108
In this paper, an improved temperature model for AlGaN/GaN high electron mobility transistor (HEMT) is presented. Research is being conducted for a high-performance building block for high frequency applications that combine lower costs with improved performance and manufacturability. The effects of channel conductance in the saturation region and the parasitic resistance due to the undoped GaN buffer layer have been included. The effect of both spontaneous and piezoelectric polarization induced charges at the AlGaN/GaN heterointerface has been incorporated. The proposed model is used to determine the transfer characteristics, output current-voltage characteristics and small-signal microwave parameters of HEMTs. The investigated temperature range is from 100–600 K. The small signal microwave parameters have been evaluated to determine the unity current gain cut-off frequency (f T ). High f T (10–70 GHz) values and high current levels (~550 mA/mm) are achieved for a 1 μm AlGaN/GaN HEMTs. A custom DC measurement system is used to facilitate the DC characterization of the unpackaged GaN HEMT test device. The calculated critical parameters and the simulation results suggest that the performance of the proposed device degrades at elevated temperatures. 相似文献
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对非线性电流源Ids(Vgs,Vds)的准确描述是Al GaN/GaN HEMT大信号模型的最重要部分之一.Materka模型考虑了夹断电压与Vds的关系,其模型参数只有三个,但是Ids与Vgs的平方关系不符合实际,计算结果与测量数据有误差.我们在考虑了栅电压与漏电流的关系及不同栅压区漏电流随漏电压斜率改变的基础上,提出了改进的高电子迁移率晶体管(HEMT)的直流特性模型.采用这个模型,计算了Al GaN/GaN HEMT器件的大信号I-V特性,并与实际测量数据进行了比较.实验结果表明改进的模型更精确,Ids与Vgs的呈2.5次方的指数关系. 相似文献
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Das J. Oprins H. Ji H. Sarua A. Ruythooren W. Derluyn J. Kuball M. Germain M. Borghs G. 《Electron Devices, IEEE Transactions on》2006,53(11):2696-2702
AlGaN/GaN high electron mobility transistors (HEMT) on sapphire substrates have been studied for their potential application in RF power applications; however, the low thermal conductivity of the sapphire substrate is a major drawback. Aiming at RF system-in-a-package, the authors propose a flip-chip-integration approach, where the generated heat is dissipated to an AlN carrier substrate. Different flip-chip-bump designs are compared, using thermal simulations, electrical measurements, micro-Raman spectroscopy, and infrared thermography. The authors show that a novel bump design, where bumps are placed directly onto both source and drain ohmic contacts, improves the thermal performance of the HEMT 相似文献
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Weijun Luo Xiaoliang Wang Hongling Xiao Cuimei Wang Junxue Ran Lunchun Guo Jianping Li Hongxin Liu Yanling Chen Fuhua Yang Jinmin Li 《Microelectronics Journal》2008,39(9):1108-1111
AlGaN/GaN high electron mobility transistor (HEMT) hetero-structures were grown on the 2-in Si (1 1 1) substrate using metal-organic chemical vapor deposition (MOCVD). Low-temperature (LT) AlN layers were inserted to relieve the tension stress during the growth of GaN epilayers. The grown AlGaN/GaN HEMT samples exhibited a maximum crack-free area of 8 mm×5 mm, XRD GaN (0 0 0 2) full-width at half-maximum (FWHM) of 661 arcsec and surface roughness of 0.377 nm. The device with a gate length of 1.4 μm and a gate width of 60 μm demonstrated maximum drain current density of 304 mA/mm, transconductance of 124 mS/mm and reverse gate leakage current of 0.76 μA/mm at the gate voltage of −10 V. 相似文献
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研制了一款X波段增强型AlGaN/GaN高电子迁移率晶体管(HEMT)。在3英寸(1英寸=2.54 cm)蓝宝石衬底上采用低损伤栅凹槽刻蚀技术制备了栅长为0.3μm的增强型AlGaN/GaN HEMT。所制备的增强型器件的阈值电压为0.42 V,最大跨导为401 mS/mm,导通电阻为2.7Ω·mm。器件的电流增益截止频率和最高振荡频率分别为36.1和65.2 GHz。在10 GHz下进行微波测试,增强型AlGaN/GaN HEMT的最大输出功率密度达到5.76 W/mm,最大功率附加效率为49.1%。在同一材料上制备的耗尽型器件最大输出功率密度和最大功率附加效率分别为6.16 W/mm和50.2%。增强型器件的射频特性可与在同一晶圆上制备的耗尽型器件相比拟。 相似文献