共查询到17条相似文献,搜索用时 593 毫秒
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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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利用金属有机化合物化学气相淀积(MOCVD)在SiC衬底上外延生长了N-polar GaN材料,采用传输线模型(TLM)分析了Ti/Al/Ni/Au金属体系在N-polar GaN上的欧姆接触特性.结果表明,Ti/Al/Ni/Au (20/60/10/50 nm)在N-polar GaN上可形成比接触电阻率为2.2×10-3Ω·cm2的非合金欧姆接触,当退火温度升至200℃,比接触电阻率降为1.44×10-3 Ω·cm2,随着退火温度的进一步上升,Ga原子外逸导致欧姆接触退化为肖特基接触. 相似文献
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以Ti/Al/Ni/Au作为欧姆接触金属体系,通过电感耦合等离子体(ICP)刻蚀的预处理,在氢化物气相外延法生长的单晶氮化镓(GaN)材料的N面实现了良好的欧姆接触,其比接触电阻率为3.7×10-4 Ω·cm2.通过扫描电子显微镜、原子力显微镜、阴极荧光和光致发光谱对GaN N面的表面、光学特性进行了对比表征.结果表明:未刻蚀GaN衬底的N面表面存在一定的损伤层,导致近表面处含有大量缺陷,不利于欧姆接触的形成;而ICP刻蚀处理有效地去除了损伤层.X射线光电子能谱(XPS)分析显示刻蚀后样品的Ga 3d结合能比未刻蚀样品向高能方向移动了约0.3 eV,其肖特基势垒则相应降低,有利于欧姆接触的形成.同时对Fe掺杂半绝缘GaN的N面也进行了刻蚀处理,同样实现了良好的Ti/Al/Ni/Au欧姆接触,其比接触电阻率为0.12 Ω·cm2. 相似文献
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基于圆形传输线模型,研究了背景载流子浓度为71016cm3的非故意掺杂GaN与Ti/Al/Ni/Au多层金属之间欧姆接触的形成。样品在N2气氛中,分别经过温度450,550,700,800,900℃的1 min快速热退火处理后发现,当退火温度高于700℃欧姆接触开始形成,随着温度升高欧姆接触电阻持续下降,在900℃时获得了最低比接触电阻6.6106O·cm2。研究表明,要获得低的欧姆接触电阻,需要Al与Ti发生充分固相反应,并穿透Ti层到达GaN表面;同时,GaN中N外扩散到金属中,在GaN表面产生N空位起施主作用,可提高界面掺杂浓度,从而有助于电子隧穿界面而形成良好欧姆接触。 相似文献
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Ti/Al/Ti/Au与AlGaN欧姆接触特性 总被引:8,自引:4,他引:4
研究了溅射 Ti/ Al/ Ti/ Au四层复合金属与 Al Ga N / Ga N的欧姆接触特性 ,并就环境温度对欧姆接触特性的影响进行了分析研究 .试验证实 :溅射的 Ti/ Al/ Ti/ Au与载流子浓度为 2 .2 4× 10 1 8cm- 3的 Al Ga N之间在室温下无需退火即可形成欧姆接触 .随快速退火温度的升高接触电阻降低 .快速退火时间 30 s已可实现该温度下最佳欧姆接触 .当工作温度不高于 30 0℃时接触电阻几乎不受温度的影响 相似文献
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Zhao Jianzhi Lin Zhaojun Lü Yuanjie Corrigan Timothy D Meng Lingguo Zhang Yu Wang Zhanguo Chen Hong 《半导体学报》2010,31(8)
Ni/Au Schottky contacts with thicknesses of either 50(A)/50(A) or 600 (A)/2000(A) were deposited on strained Al0.3Ga0.7N/GaN heterostructures.Using the measured C-V curves and Ⅰ-Ⅴ characteristics at room temperature,the calculated density of the two-dimensional electron-gas (2DEG) of the 600(A)/2000(A) thick Ni/Au Schottky contact is about 9.13 x 1012 cm-2 and that of the 50(A)/50(A) thick Ni/Au Schottky contact is only about 4.77 ×1012 cm-2.The saturated current increases from 60.88 to 86.34 mA at a bias of 20 V as the thickness of the Ni/Au Schottky contact increases from 50(A)/50(A)to 600(A)/2000(A).By self-consistently solving Schrodinger's and Poisson's equations,the polarization charge sheet density of the two samples was calculated,and the calculated results show that the polarization in the AIGaN barrier layer for the thick Ni/Au Schottky contact is stronger than the thin one.Thus,we attribute the results to the increascd biaxial tensile stress in the Al0.3Ga0.7N barrier layer induced by the 600(A)/2000(A)thick Ni/Au Schottky contact. 相似文献
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We report the effect of the Pt barrier on the thermal stability of Ti/Al/Pt/Au in ohmic contact with Si-implanted n-type GaN
layers. Ti/Al/Au (25/100/200 nm) and Ti/Al/Pt/Au (25/100/50/200 nm) multilayers were, respectively, deposited on as-implanted
and recovered Si-implanted n-type GaN samples. The associated dependence of the specific contact resistance on the annealing
time at various temperatures was compared. The long-term ohmic stability of a Ti/Al/Pt/Au multilayer in contact with a Si-implanted
n-type GaN layer was much better than that of the Ti/Al/Au multilayer. This superior stability is attributed to the barrier
function of the Pt interlayer. The Pt/Au bilayer can also passivate the propensity of oxidation for the conventional Ti/Al
bilayer in contact with n-type GaN layers at elevated temperatures. 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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Jong Kyu Kim Jung Ho Je Jae Won Lee Yong Jo Park Taeil Kim In-Ok Jung Byung-Teak Lee Jong-Lam Lee 《Journal of Electronic Materials》2001,30(2):L8-L12
Electrical properties of Ni/Au ohmic contacts on p-type GaN were interpreted with the change of microstructure observed under
transmission electron microscopy. The contact resistivity was decreased from 1.3×10−2 to 6.1×10−4 Ωcm2 after annealing at 600°C. The reduction is due to the dissolution of Ga atoms into Au−Ni solid solution formed during annealing,
via the generation of Ga vacancies. Thus, net concentration of holes increased below the contact, resulting in the reduction
of contact resistivity. At 800°C, N atoms decomposed; reacted with Ni, and forming cubic Ni4N. Consequently, N vacancies, acting as donors in GaN, were generated below the contact, leading to the increase of contact
resistivity to 3.8×10−2 Ωcm2. 相似文献
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The features of the formation of Ta/Ti/Al/Mo/Au ohmic contacts to a Al0.26Ga0.74N/AlN/GaN heterostructure grown on semi-insulating Si(111) substrates are studied. The dependences of the contact resistance on the Al (90, 120, 150, 180 nm) and Ti (15, 30 nm) layer thickness and optimal temperature-time annealing conditions are determined for each studied metallization scheme. It is shown that the minimum achievable contact resistance monotonically increases from 0.43 to 0.58 Ω mm as the Al layer thickness increases from 90 to 180 nm at unchanged Ta, Ti, Mo, Au layer thicknesses. A change in the Ti layer thickness from 15 to 30 nm has no significant effect on the minimum contact resistance. The least contact resistance of 0.4 Ω mm is achieved for Ta/Ti/Al/Mo/Au layers with thicknesses of 10/15/90/40/25 nm, respectively. The optimal annealing temperature for this metallization variant is 825°C at a process duration of 30 s. The grown ohmic contacts have smooth contact-area edges and flat morphology of their surface. 相似文献