共查询到18条相似文献,搜索用时 60 毫秒
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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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基于SiC衬底AlGaN/GaN异质结材料研制具有高电流增益截止频率(fT)和最大振荡频率(fmax)的AlGaN/GaN异质结场效应晶体管(HFETs).基于MOCVD外延n+ GaN 欧姆接触工艺实现了器件尺寸的缩小, 有效源漏间距(Lsd)缩小至600 nm.此外, 采用自对准工艺制备了60 nm T型栅.由于器件尺寸的缩小, 在Vgs=2 V下, 器件最大饱和电流(Ids)达到2.0 A/mm, 该值为AlGaN/GaN HFETs器件直流测试下的最高值, 器件峰值跨导达到608 mS/mm.小信号测试表明, 器件fT和fmax最高值分别达到152 GHz和219 GHz. 相似文献
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AlGaN/GaN界面特性研究进展 总被引:2,自引:0,他引:2
GaN是一种宽禁带半导体材料,由于具有优越的热稳定性和化学稳定性,使这种材料和与其相关的器件可以工作在高温和恶劣的环境中,并可用于大功率微波器件。本文主要介绍AlGaN/GaN有关界面特性,该特性反映了纵向纳米尺度下的能带特性;从AlGaN/GaNHEMT设计出发,给出了材料性质和结构参数对AlGaN/GaN异质结二维电子气特性影响的研究结果;讨论了AlGaN/GaN界面2DEG载流子的输运性质;分析了材料缺陷对AlGaN/GaN界面2DEG性质的影响;指出了有待研究的问题和方向。 相似文献
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《Electron Device Letters, IEEE》2009,30(12):1254-1256
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Nidhi Palacios T. Chakraborty A. Keller S. Mishra U.K. 《Electron Device Letters, IEEE》2006,27(11):877-880
This letter studies the effect of access resistance on the high-frequency performance of AlGaN/GaN high-electron-mobility transistors. To systematically reduce the sheet access resistance, the transistors were measured at different temperatures. The increase of mobility at lower temperatures allowed more than four-fold reduction in the sheet access resistances. Both the current- and power-gain cutoff frequencies are observed to increase at low temperatures. Also, the intrinsic effective velocity has been estimated in these devices, as well as the parasitic delays involved in the final performance. Channel charging delay, which was expected to be most sensitive to parasitics, is observed to decrease at low temperatures. However, the drain delay, intrinsic delay, and effective electron velocity remain unaffected by temperature 相似文献
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Short-Channel Effect Limitations on High-Frequency Operation of AlGaN/GaN HEMTs for T-Gate Devices 总被引:4,自引:0,他引:4
Jessen G.H. Fitch R.C. Gillespie J.K. Via G. Crespo A. Langley D. Denninghoff D.J. Trejo M. Heller E.R. 《Electron Devices, IEEE Transactions on》2007,54(10):2589-2597
AlGaN/GaN high-electron mobility transistors (HEMTs) were fabricated on SiC substrates with epitaxial layers grown by multiple suppliers and methods. Devices with gate lengths varying from 0.50 to 0.09 mum were fabricated on each sample. We demonstrate the impact of varying the gate lengths and show that the unity current gain frequency response (fT) is limited by short-channel effects for all samples measured. We present an empirically based physical model that can predict the expected extrinsic fT for many combinations of gate length and commonly used barrier layer thickness (tbar) on silicon nitride passivated T-gated AlGaN/GaN HEMTs. The result is that even typical high-aspect-ratio (gate length to barrier thickness) devices show device performance limitations due to short-channel effects. We present the design tradeoffs and show the parameter space required to achieve optimal frequency performance for GaN technology. These design rules differ from the traditional GaAs technology by requiring a significantly higher aspect ratio to mitigate the short-channel effects. 相似文献
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研究了Al GaN/GaN HEMT制备中相关工艺对器件肖特基特性的影响,并对工艺进行了优化。首先研究了表面处理对器件肖特基势垒特性的影响,对不同的表面处理方法进行了比较,发现采用氧等离子体处理,并用V(HF)∶V(H2O)=1∶5溶液清洗刻蚀后的表面,可以有效减小表面态密度,未经处理的样品肖特基接触理想因子为2.6,处理后理想因子减小到1.8。对Si N钝化膜的折射率与肖特基特性的关系进行了研究,发现Si N钝化膜的折射率为2.3~2.4时,钝化对肖特基特性的影响较小,但反向泄漏电流较大。 相似文献
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用Silvaco的ATLAS软件模拟了栅场板参数对AlGaN/GaN HEMT中电场分布的影响.模拟结果表明,场板的加入改变了器件中电势的分布情况,降低了栅边缘处的电场峰值,改善了器件的击穿特性;场板长度(LFP,length of field plate)、场板与势垒层间的介质层厚度t等对电场的分布影响很大.随着LFP的增大、t的减小,栅边缘处的电场峰值Epeak1明显下降,对提高器件的耐压非常有利.通过对相同器件结构处于不同漏压下的情况进行模拟,发现当器件处于高压下时,场板的分压作用更加明显,说明场板结构更适合于制备用作电力开关器件的高击穿电压AlGaN/GaN HEMT. 相似文献
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为了研究适合Ka波段AlGaN/GaN HEMT的栅结构尺寸,借助二维器件仿真软件Silvaco Atlas,在完善仿真模型的基础上研究了Γ型栅各部分对AlGaN/GaN HEMT特性的影响,包括栅长与短沟道效应的关系、栅与沟道距离对短沟道效应和饱和漏电流的影响,以及栅金属厚度对fmax,栅场板对fT、fmax和内部电场的影响。根据典型器件结构和材料参数的仿真表明,为了提高频率并减轻短沟道效应,栅长应取0.15~0.25μm;减小栅与沟道的距离可略微改善短沟道效应,但会明显降低器件的饱和漏电流,综合考虑栅调制能力、饱和漏电流、短沟道效应三个方面,栅与沟道距离应取10~20nm;为了提高fmax,栅金属厚度应大于0.4μm;缩小栅场板长度可有效提高器件的频率,兼顾Ka波段应用和提高击穿电压,栅场板长度应在0.3~0.4μm左右。仿真得出的器件性能随结构参数的变化趋势以及尺寸数据对于Ka波段AlGaN/GaN HEMT的研究具有参考意义。 相似文献
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《Electron Device Letters, IEEE》2009,30(8):808-810