共查询到20条相似文献,搜索用时 0 毫秒
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M. Kocan G.A. Umana-Membreno J.S. Chung F. Recht L. McCarthy S. Keller U.K. Mishra G. Parish B.D. Nener 《Journal of Electronic Materials》2007,36(9):1156-1159
This paper reports results of a study of non-alloyed ohmic contacts on Si-implanted AlGaN/GaN heterostructures, obtained from
current–voltage characteristics of transfer-length method (TLM) test structures. It is shown that the measured contact resistance
from the Ti/Au/Ni metal contacts, deposited on Si-implanted regions, to the two-dimensional electron gas channel at the AlGaN/GaN
heterointerface of the non-implanted region, is formed by three different components: (i) contact resistance between the metal␣and
the semiconductor (0.60 ± 0.16 Ω mm), (ii) resistance of the implanted region (0.62 ± 0.03 Ω mm) and (iii) an additional resistance
(0.72 ± 0.24 Ω mm) giving a total value of 1.9 ± 0.3 Ω mm. The specific ohmic contact resistance was determined to be (2.4 ± 0.5) × 10−5 Ω cm2. 相似文献
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Rongming Chu Likun Shen Fichtenbaum N. Brown D. Keller S. Mishra U.K. 《Electron Device Letters, IEEE》2008,29(4):297-299
It has been found that the reverse leakage current of AlGaN/GaN Schottky contacts can be significantly reduced by a CF4 plasma treatment prior to the Schottky metal evaporation. The data of electrical characterization suggest that the leakage reduction is related to the modification of the semiconductor surface by plasma treatment. The leakage reduction effect was also observed in GaN Schottky contacts. Capacitance-voltage characterization of the GaN Schottky contacts indicates that the Schottky barrier height was slightly increased by the plasma treatment. A two-step surface treatment procedure, consisting of a BCI3 plasma treatment followed by a brief CF4 plasma treatment, has been developed as an efficient approach to reduce the reverse leakage of the Schottky contacts, while avoiding side effects related to the CF4 plasma. 相似文献
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Chung-Yu Lu Edward Yi Chang Jui-Chien Huang Chia-Ta Chang Mei-Hsuan Lin Ching-Tung Lee 《Journal of Electronic Materials》2008,37(5):624-627
Tungsten, stoichiometric W2N, and nitrogen-rich W2N films were used as Schottky contacts on AlGaN/GaN heterostructures. The nitrogen content in the film was controlled by varying
the nitrogen-to-argon gas flow ratio during the reactive sputter deposition. The diode with the nitrogen-rich film exhibited
a higher Schottky barrier height and the leakage current was comparable to that of the Ni/Au Schottky contact. Analysis suggested
that this was due to the increase of the tungsten nitride work function as the result of higher nitrogen incorporation. Furthermore,
after 600°C thermal annealing, the diode was stable and showed no change in the leakage current. 相似文献
5.
Low-Temperature Ta/Al-Based Ohmic Contacts to AlGaN/GaN Heteroepitaxial Structures on Silicon Wafers
Semiconductors - The formation features of a low-temperature Ta/Al-based ohmic contact to Al0.25Ga0.75N/GaN heteroepitaxial structures on silicon substrates are studied. The fabricated ohmic... 相似文献
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Benedict Ofuonye Jaesun Lee Minjun Yan Qhalid Fareed Iftikhar Ahmad Asif Khan Ilesanmi Adesida 《Journal of Electronic Materials》2011,40(12):2344-2347
The effect of high-temperature annealing of undoped AlGaN/GaN heterostructures on different substrates was systematically
studied between 1100°C and 1230°C. An AlN spacer layer was found to add stability to structures on sapphire substrates. AlGaN/GaN
heterostructures on SiC substrates demonstrated excellent robustness for the temperature range studied, maintaining their
mobility, sheet resistance, and sheet concentration values, even after annealing. A silicon nitride, SiN
x
, capping layer was found to assist in minimizing surface roughness during annealing and maintaining the electrical characteristics
of the heterostructures. AlGaN/GaN heterostructures on SiC substrates showed a 20% decrease in mobility for uncapped samples
compared with SiN
x
-capped samples. 相似文献
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Egorkin V. I. Bespalov V. A. Zaitsev A. A. Zemlyakov V. E. Kapaev V. V. Kukhtyaeva O. B. 《Semiconductors》2021,55(13):1039-1044
Semiconductors - Conventional AlGaN/GaN transistors are depletion-mode devices. For most applications, the E-mode, where the channel current is zero at the zero gate voltage, should be implemented.... 相似文献
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Enisherlova K. L. Medvedev B. K. Temper E. M. Korneev V. I. 《Russian Microelectronics》2019,48(8):564-575
Russian Microelectronics - The effect of the microrelief, dislocation structure, and other defects of epitaxial layers in the source and drain regions of a Nitride High Electron Mobility Transistor... 相似文献
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作为制备光电子器件例如紫外光子探测器、异质结场效应晶体管(HFET)、高电子迁移率晶体管(HEMT)异质结场效应管等的一种宽禁带半导体材料, III V 族氮化物AlGaN器件近年来颇受关注.AlGaN与金属之间的低阻欧姆接触的实现问题阻碍了AlGaN(基)器件的发展.通过对相关文献的归纳分析,介绍了近年来AlGaN器件在欧姆接触形成、金属化方案、合金化工艺及表面处理等方面的研究进展. 相似文献
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采用Ti/Al/Ni/Au多层金属体系在Al0.27Ga0.73N/GaN异质结构上制备了欧姆接触. 分别采用线性传输线方法(LTLM)和圆形传输线方法(CTLM)对其电阻率进行了测试. 当Ti(10nm)/Al(100nm)/Ni(40nm)/Au(100nm)金属体系在650℃高纯N2气氛中退火30s时,测量得到的最小比接触电阻率为1.46E-5Ω·cm2. 并制备了Al0.27Ga0.73N/GaN光导型紫外探测器,通过测试发现探测器的暗电流-电压曲线呈线性分布. 实验结果表明在Al0.27Ga0.73N/GaN异质结构上获得了好的欧姆接触,能够满足制备高性能AlGaN/GaN紫外探测器的要求. 相似文献
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研究了 Ga N高温宽禁带半导体外延层上欧姆接触的制备工艺 ,讨论了几种测试方法的优缺点 ,并根据器件制作的工艺兼容性 ,在 n-Ga N样品上获得了 4× 1 0 - 6 Ω·cm2的欧姆接触 ,在 Al Ga N/Ga N异质结构样品上获得了 4× 1 0 - 4Ω· cm2 的欧姆接触。实验结果表明 ,Al Ga N/Ga N上低阻欧姆接触的制备及其工艺兼容性是Ga N HFET器件研制的技术难点 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
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采用归一化能量1 MeV的中子脉冲反应堆对AlGaN/GaN异质结材料进行了辐照研究.实验发现,经1015cm-2注量的中子辐照后,异质结材料的二维电子气(2DEG)载流子浓度(ns)下降,而2DEG迁移率由于受到ns的调制作用略有增加,同时辐照导致的载流子浓度ns下降造成了沟道串联电阻的增加和异质结构阈值电压(VTH)的正向漂移.分析认为,辐照感生类受主缺陷是造成ns下降和阈值电压漂移的原因.原子力显微镜(AFM)和X射线衍射仪(XRD)的测试结果表明,辐照后材料的表面形貌有所恶化,材料应变基本不变,而材料的螺位错和刃位错密度辐照后都略有增加.此外,实验结果还表明初始材料质量越好,辐照退化越小. 相似文献
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提出了新型的Ni/Ag/Pt结构作为具有高光学反射率、低比接触电阻率(SCR)的p-GaN欧姆接触电极。在Ni/Ag/Pt厚度分别为3 nm/120 nm/2 nm的条件下,在500℃、O2气氛中退火3 min,获得了80%的光学反射率(460 nm处)和4.43×10-4Ω.cm2的SCR,样品的表面均方根(RMS)粗糙度约为8nm。俄歇电子能谱(AES)分析表明,Pt很好地改善了Ag基电极退火后的表面形貌,Ni、Ag对形成良好的欧姆接触起了重要的作用。 相似文献
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Liang?Pang Hui-Chan?Seo Patrick?Chapman Ilesanmi?Adesida Kyekyoon ?Kim 《Journal of Electronic Materials》2010,39(5):499-503
Selective-area growth (SAG) based on plasma-assisted molecular-beam epitaxy (PAMBE) was shown to facilitate improvement of
Ohmic contacts and direct-current (DC) characteristics for GaN-based field-effect transistors (FETs) over the widely accepted
ion-implantation technique. Twofold improvements in breakdown voltage were also demonstrated for samples grown on both sapphire
and silicon substrates. An AlGaN/GaN high-electron-mobility transistor (HEMT) fabricated with PAMBE-SAG exhibited a low specific
contact resistivity of 5.86 × 10−7 Ω cm2, peak drain current of 420 mA/mm, and high breakdown voltage of 77 V. These results demonstrate that PAMBE-SAG is suited
to fabricating HEMTs for high-power applications. 相似文献
19.
Shigekawa N. Nishimura K. Yokoyama H. Hohkawa K. 《Electron Devices, IEEE Transactions on》2008,55(7):1585-1591
Properties of surface acoustic waves (SAWs) in reverse-biased AlGaN/GaN heterostructures on (0001) sapphire substrates were studied by examining the characteristics of SAW filters composed of interdigital Schottky and ohmic contacts. The fundamental and higher frequency SAW signals in measured -parameters were attributed to Rayleigh and Sezawa modes, respectively. The onsets of the SAW signals, which were close to the threshold voltage of HEMTs in the vicinities of the respective filters, changed in response to the spatial variation of the threshold voltage. The onset of Sezawa mode was deeper than that of Rayleigh mode, and the difference in onset was larger for longer SAW wavelengths. These results are possibly explained by the change of the input capacitance of interdigital transducers due to the reverse-bias voltages or by the difference in the distribution of SAW energy between the two modes. 相似文献