共查询到20条相似文献,搜索用时 15 毫秒
1.
Milan Ťapajna Nicole Killat Uttiya Chowdhury Jose L. Jimenez Martin Kuball 《Microelectronics Reliability》2012,52(1):29-32
Reliability of AlGaN/GaN HEMTs processed with different surface oxidation levels was studied using electrical and optical methods. It was found that HEMTs with more surface oxide content are more susceptible to degradation in terms of gate leakage and trapping characteristics, although this oxide layer initially passivates surface traps. In the degraded devices, trap level with activation energy of 0.45–0.47 eV was observed and attributed to surface related traps. This indicates that oxygen may play a crucial role for AlGaN/GaN HEMT reliability. 相似文献
2.
研究了蓝宝石衬底AlGaN/GaN共栅共源器件的特性。该器件包括栅长0.8μm共源器件与栅长1μm的共栅器件。研究表明,共栅共源器件的第二栅压对的器件饱和电流与跨导有明显的调制作用,容易实现功率增益控制。与共源器件相比,共栅共源器件在微波特性上fT大约9GHz,比共源器件稍小,但是具有较低的反馈,显著增加的功率资用增益及较高的端口阻抗,与共源器件相比,稳定性更好,可以避免振荡的产生,结合GaN的高功率特性GaN共栅共源器件非常适合微波频段宽频大功率领域的应用。 相似文献
3.
High-performance E-mode AlGaN/GaN HEMTs 总被引:1,自引:0,他引:1
Palacios T. Suh C.-S. Chakraborty A. Keller S. DenBaars S.P. Mishra U.K. 《Electron Device Letters, IEEE》2006,27(6):428-430
Enhancement-mode AlGaN/GaN high electron-mobility transistors have been fabricated with a gate length of 160 nm. The use of gate recess combined with a fluorine-based surface treatment under the gate produced devices with a threshold voltage of +0.1 V. The combination of very high transconductance (> 400 mS/mm) and low gate leakage allows unprecedented output current levels in excess of 1.2 A/mm. The small signal performance of these enhancement-mode devices shows a record current cutoff frequency (f/sub T/) of 85 GHz and a power gain cutoff frequency (f/sub max/) of 150 GHz. 相似文献
4.
Xiaolong Cai Chenglin Du Zixuan Sun Ran Ye Haijun Liu Yu Zhang Xiangyang Duan Hai Lu 《半导体学报》2021,42(5):37-48
Gallium nitride (GaN)-based high-electron mobility transistors (HEMTs) are widely used in high power and high frequency application fields,due to the outstanding physical and chemical properties of the GaN material.However,GaN HEMTs suffer from degradations and even failures during practical applications,making physical analyses of post-failure devices extremely significant for reliability improvements and further device optimizations.In this paper,common physical characterization techniques for post failure analyses are introduced,several failure mechanisms and corresponding failure phenomena are reviewed and summarized,and finally device optimization methods are discussed. 相似文献
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Enhancement-mode AlGaN/GaN HEMTs on silicon substrate 总被引:3,自引:0,他引:3
Shuo Jia Yong Cai Deliang Wang Baoshun Zhang Lau K.M. Chen K.J. 《Electron Devices, IEEE Transactions on》2006,53(6):1474-1477
High-performance enhancement-mode AlGaN/GaN HEMTs (E-HEMTs) were demonstrated with samples grown on a low-cost silicon substrate for the first time. The fabrication process is based on a fluoride-based plasma treatment of the gate region and postgate annealing at 450 /spl deg/C. The fabricated E-HEMTs have nearly the same peak transconductance (G/sub m/) and cutoff frequencies as the conventional depletion-mode HEMTs fabricated on the same wafer, suggesting little mobility degradation caused by the plasma treatment. 相似文献
6.
Temperature-dependent nonlinearities of GaN/AlGaN HEMTs are reported. The large-signal device model of the transistor is obtained by using a physics-based analysis. The model parameters are obtained as functions of bias voltages and temperature. The analysis of the device has been carried out using a time-domain technique. fmax for a 0.23 μm×100 μm Al0.13Ga0.87N/GaN FET is calculated as 69 GHz at 300 K, while at 500 K, fmax decreases to 30 GHz, which are in agreement with the experimental data within 7% error. fmax as obtained from calculated unilateral gain, decreases monotonically with increasing temperature. For shorter gate lengths irrespective of the operating temperature fmax is less sensitive to bias voltage scaling. For longer gate length devices, fmax becomes less sensitive to the bias voltage scaling at elevated temperatures. 1-dB compression point (P1-dB ) at 4 GHz for a 1 μm×500 μm Al0.15Ga0.85N/GaN FET is 13 dBm at 300 K. At 500 K, P1-dB decreases to 2.5 dBm for the same operating frequency. Similar results for output referred third intercept point (OIP3) are reported for different gate length devices 相似文献
7.
Changxi Chen Quan Wang Wei Li Qian Wang Chun Feng Lijuan Jiang Hongling Xiao Xiaoliang Wang 《半导体学报》2021,42(9):57-62
In this paper,we investigated the effect of post-gate annealing (PGA) on reverse gate leakage and the reverse bias reli-ability of Al0.23Ga0.77N/GaN high electron mobility transistors (HEMTs).We found that the Poole-Frenkel (PF) emission is domin-ant in the reverse gate leakage current at the low reverse bias region (Vth < VG < 0 V) for the unannealed and annealed HEMTs.The emission barrier height of HEMT is increased from 0.139 to 0.256 eV after the PGA process,which results in a reduction of the reverse leakage current by more than one order.Besides,the reverse step stress was conducted to study the gate reliabil-ity of both HEMTs.After the stress,the unannealed HEMT shows a higher reverse leakage current due to the permanent dam-age of the Schottky gate.In contrast,the annealed HEMT shows a little change in reverse leakage current.This indicates that the PGA can reduce the reverse gate leakage and improve the gate reliability. 相似文献
8.
Shen L. Coffie R. Buttari D. Heikman S. Chakraborty A. Chini A. Keller S. DenBaars S.P. Mishra U.K. 《Electron Device Letters, IEEE》2004,25(1):7-9
In this paper, a high-power GaN/AlGaN/GaN high electron mobility transistor (HEMT) has been demonstrated. A thick cap layer has been used to screen surface states and reduce dispersion. A deep gate recess was used to achieve the desired transconductance. A thin SiO/sub 2/ layer was deposited on the drain side of the gate recess in order to reduce gate leakage current and improve breakdown voltage. No surface passivation layer was used. A breakdown voltage of 90 V was achieved. A record output power density of 12 W/mm with an associated power-added efficiency (PAE) of 40.5% was measured at 10 GHz. These results demonstrate the potential of the technique as a controllable and repeatable solution to decrease dispersion and produce power from GaN-based HEMTs without surface passivation. 相似文献
9.
High-power AlGaN/GaN HEMTs for Ka-band applications 总被引:2,自引:0,他引:2
Palacios T. Chakraborty A. Rajan S. Poblenz C. Keller S. DenBaars S.P. Speck J.S. Mishra U.K. 《Electron Device Letters, IEEE》2005,26(11):781-783
We report on the fabrication and high-frequency characterization of AlGaN/GaN high-electron mobility transistors (HEMTs) grown by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD). In devices with a gate length of 160 nm, a record power density of 10.5 W/mm with 34% power added efficiency (PAE) has been measured at 40 GHz in MOCVD-grown HEMTs biased at V/sub DS/=30 V. Under similar bias conditions, more than 8.6 W/mm, with 32% PAE, were obtained on the MBE-grown sample. The dependence of output power, gain, and PAE on gate and drain voltages, and frequency have also been analyzed. 相似文献
10.
N. Malbert N. Labat A. Curutchet C. Sury V. Hoel J.-C. de Jaeger N. Defrance Y. Douvry C. Dua M. Oualli C. Bru-Chevallier J.-M. Bluet W. Chikhaoui 《Microelectronics Reliability》2009,49(9-11):1216-1221
This work is a study of the degradations of AlGaN/GaN HEMTs induced by 2000 h of ageing tests. The methodology is based on cross-characterisation analysis.The life tests (HTO 150 °C, HTO 175 °C and HTRB 175 °C and Idq 90 °C) have mainly induced a decrease of the saturation drain current, occurring during the first 50 h, followed by a stabilisation. There is a shift of the pinch-off voltage in the range of 0.1–0.2 V while the Schottky contact is rather stable after ageing. The evolution of the electrical characteristics after ageing does not depend on the bias conditions but rather more on the channel temperature. It seems to be neither field nor current driven. Low frequency drain current noise demonstrates that there is no trap creation and the weak evolution of the 1/f noise confirms that there is no degradation in the channel. Moreover, pulsed I–V measurements show a weak evolution of gate lag and drain lag rates after ageing. The same degradation mode is demonstrated for all life tests with rather high activation energy of 1.6 eV. The weak evolution of electrical characteristics observed during the life tests cannot be obviously explained by a single physical mechanism and results from a combination of trap-related effects before stabilisation. 相似文献
11.
Gain and intermodulation distortion of an AlGaN/GaN device operating at RF have been analyzed using a general Volterra series representation. The circuit model to represent the GaN FET is obtained from a physics-based analysis. Theoretical current-voltage characteristics are in excellent agreement with the experimental data. For a 1 μm×500 μm Al0.15Ga0.85N/GaN FET, the calculated output power, power-added efficiency, and gain are 25 dBm, 13%, and 10.1 dB, respectively, at 15-dBm input power, and are in excellent agreement with experimental data. The output referred third-order intercept point (OIP3) is 39.9 dBm at 350 K and 33 dBm at 650 K. These are in agreement with the simulated results from Cadence, which are 39.34 and 35.7 dBm, respectively. At 3 GHz, third-order intermodulation distortion IM3 for 10-dBm output power is -72 dB at 300 K and -56 dB at 600 K. At 300 K, IM3 is -66 dB at 5 GHz and -51 dB at 10 GHz. For the same frequencies, IM 3 increases to -49.3 and -40 dB, respectively, at 600 K 相似文献
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随着高压开关和高速射频电路的发展,增强型GaN基高电子迁移率晶体管(HEMT)成为该领域内的研究热点。增强型GaN基HEMT只有在加正栅压才有工作电流,可以大大拓展该器件在低功耗数字电路中的应用。近年来,国内外对增强型GaN基HEMT阈值电压的研究主要集中以下两个方面:在材料生长方面,通过生长薄势垒、降低Al组分、生长无极化电荷的AlGaN/GaN异质材料、生长InGaN或p-GaN盖帽层,来控制二维电子气浓度;在器件工艺方面,采用高功函数金属、MIS结构、刻蚀凹栅、F基等离子体处理,来控制表面电势,影响二维电子气浓度。从影响器件阈值电压的相关因素出发,探讨了实现和优化增强型GaN基HEMT的各种工艺方法和发展方向。 相似文献
15.
AlGaN/GaN high electron mobility transistors (HEMTs) on 6H-SiC with varying field-plate length and gate-drain spacing were fabricated and analyzed. The classical small signal FET model and the well-known ColdFET method were used to extract the small signal parameters of the devices. Though the devices with field plates exhibited lower better fT characteristic, they did demonstrate better fmax, MSG and power density performances than the conventional devices without field plate. Besides, no independence of DC characteristic on field-plate length was observed. With the increase of the field-plate length and the gate-drain spacing, the characteristic of fT and fmax degraded due to the large parasitic effects. Loadpull method was used to measure the microwave power performance of the devices. Under the condition of continuous wave at 5.4 GHz, an output power density of 4.69 W/mm was obtained for device with field-plate length of 0.5 μm and gate-drain length of 2 μm. 相似文献
16.
Punchthrough-Voltage Enhancement of AlGaN/GaN HEMTs Using AlGaN Double-Heterojunction Confinement 总被引:1,自引:0,他引:1
《Electron Devices, IEEE Transactions on》2008,55(12):3354-3359
17.
Current Collapse and High-Electric-Field Reliability of Unpassivated GaN/AlGaN/GaN HEMTs 总被引:4,自引:0,他引:4
Gaudenzio Meneghesso Fabiana Rampazzo Peter Kordos Giovanni Verzellesi Enrico Zanoni 《Electron Devices, IEEE Transactions on》2006,53(12):2932-2941
Long-term ON-state and OFF-state high-electric-field stress results are presented for unpassivated GaN/AlGaN/GaN high-electron-mobility transistors on SiC substrates. Because of the thin GaN cap layer, devices show minimal current-collapse effects prior to high-electric-field stress, despite the fact that they are not passivated. This comes at the price of a relatively high gate-leakage current. Under the assumption that donor-like electron traps are present within the GaN cap, two-dimensional numerical device simulations provide an explanation for the influence of the GaN cap layer on current collapse and for the correlation between the latter and the gate-leakage current. Both ON-state and OFF-state stresses produce simultaneous current-collapse increase and gate-leakage-current decrease, which can be interpreted to be the result of gate-drain surface degradation and reduced gate electron injection. This study shows that although the thin GaN cap layer is effective in suppressing surface-related dispersion effects in virgin devices, it does not, per se, protect the device from high-electric-field degradation, and it should, to this aim, be adopted in conjunction with other technological solutions like surface passivation, prepassivation surface treatments, and/or field-plate gate 相似文献
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研究了源漏整体刻蚀欧姆接触结构对AlGaN/GaN高电子迁移率晶体管(HEMT)的欧姆接触电阻和金属电极表面形貌的影响.利用传输线模型(TLM)对样品的电学性能进行测试,使用原子力显微镜(AFM)对样品的表面形貌进行表征,通过透射电子显微镜(TEM)和X射线能谱仪(EDS)对样品的剖面微结构和界面反应进行表征与分析.实验结果显示,采用Ti/Al/Ni/Au(20 nm/120 nm/45 nm/55 nm)金属和源漏整体刻蚀欧姆接触结构,在合金温度870 c℃,升温20 s,退火50 s条件下,欧姆接触电阻最低为0.13 Ω·mm,方块电阻为363.14 Ω/□,比接触电阻率为4.54×10-7Ω·cm2,形成了良好的欧姆接触,降低了器件的导通电阻. 相似文献