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p型GaN欧姆接触的研究进展 总被引:2,自引:1,他引:1
宽带隙的GaN作为半导体领域研究的热点之一,近年来发展得很快.p型GaN的欧姆接触问题一直阻碍高温大功率GaN基器件的研制.本文讨论了金属化方案的选择、表面预处理和合金化处理等几个问题,回顾了近年来p型GaN欧姆接触的研究进展. 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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碳化硅(SiC)具有宽禁带、高临界击穿电场、高热导率等优异特性,是制备高温、高频、大功率器件最理想的半导体材料之一。然而,制备良好的SiC欧姆接触尤其是p型SiC欧姆接触仍然是SiC器件研制中亟需攻克的关键技术难题。首先对p型SiC欧姆接触的形成机制及金属/SiC接触势垒理论进行了深入分析。然后,对近年来p型SiC欧姆接触的重要研究进展进行了综述,包括形成欧姆接触的金属体系,制备工艺条件,获得的比接触电阻率等,并重点讨论了p型SiC欧姆接触的形成机理。最后,对未来p型SiC欧姆接触的研究方向进行了展望。 相似文献
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提出了一种GaN薄膜电学参量测试新方法.该方法基于双肖特基结二极管结构,利用非对称的电极图形获取整流特性,从而省去了复杂的欧姆接触形成工艺,可方便地导出电子电导迁移率和肖特基接触理想因子等特征参数.对残留载流子浓度为7×1016 cm-3 的非故意掺杂GaN薄膜进行了试验,新方法得到Ni/Au-GaN肖特基接触的理想因子为2.8,GaN薄膜方块电阻为491Ω和电子电导迁移率为606cm2/(V·s).这些典型参数与利用欧姆接触实验和普通Ni/Au-GaN肖特基二极管测试所得结果较为吻合.该方法为半导体薄膜测试提供了新思路,可推广用于难以形成良好线性欧姆接触或材料特性受欧姆接触工艺影响较大的外延材料及其金半接触的监测研究. 相似文献
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提出了一种GaN薄膜电学参量测试新方法.该方法基于双肖特基结二极管结构,利用非对称的电极图形获取整流特性,从而省去了复杂的欧姆接触形成工艺,可方便地导出电子电导迁移率和肖特基接触理想因子等特征参数.对残留载流子浓度为7×1016 cm-3 的非故意掺杂GaN薄膜进行了试验,新方法得到Ni/Au-GaN肖特基接触的理想因子为2.8,GaN薄膜方块电阻为491Ω和电子电导迁移率为606cm2/(V·s).这些典型参数与利用欧姆接触实验和普通Ni/Au-GaN肖特基二极管测试所得结果较为吻合.该方法为半导体薄膜测试提供了新思路,可推广用于难以形成良好线性欧姆接触或材料特性受欧姆接触工艺影响较大的外延材料及其金半接触的监测研究. 相似文献
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分别用稀盐酸、王水以及(NH4)2S溶液处理p-GaN表面,通过测试样品表面Ols的X射线光电子能谱(XPS),比较了这些溶液去除p-GaN表面氧化层的能力;在经不同溶液处理后的样品表面,以相同的条件制作Ni/Au电极,并测试其与p-GaN的比接触电阻,结果表明经稀盐酸处理后的样品表面,由于其氧含量较高,不能与Ni/Au形成良好的欧姆接触,而经王水和(NH4)2S溶液处理后的p-GaN表面,能与Ni/Au形成良好的欧姆接触;最后,通过比较样品表面的Ga/N原子浓度比,探讨了王水处理p-GaN表面能够形成良好欧姆接触的原因. 相似文献
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Ippei Fujimoto Hirokuni Asamizu Masahiro Shimada Miki Moriyama Naoki Shibata Masanori Murakami 《Journal of Electronic Materials》2003,32(9):957-963
To understand formation and deterioration mechanisms of Ta/Ti ohmic contacts that were previously developed for p-GaN, the
electrical properties of the Ta/Ti contacts, which were deposited on undoped GaN substrates and subsequently annealed in vacuum
(where a slash (/) sign indicates the deposition sequence), were studied. The Ta/Ti contacts displayed good ohmic behavior
after annealing at a temperature of 800°C for 10 min in vacuum, although the undoped GaN substrates were used. However, deterioration
of the present ohmic contacts was observed during room-temperature storage. These contact properties were similar to those
observed in the Ta/Ti contacts prepared on p-GaN. Hall-effect measurements revealed that thin n-type conductive layers were
found to form on surfaces of both the undoped GaN and p-GaN substrates after annealing at 800°C in vacuum. 相似文献
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Effects of annealing in an oxygen ambient on electrical properties of ohmic contacts to p-type GaN 总被引:3,自引:0,他引:3
Yasuo Koide T. Maeda T. Kawakami S. Fujita T. Uemura N. Shibata Masanori Murakami 《Journal of Electronic Materials》1999,28(3):341-346
Effects of annealing ambient of an oxygen and nitrogen mixed gas on the electrical properties were studied for Au-based ohmic
contacts (NiAu, CoAu, CuAu, PdAu, and PtAu) to p-type GaN. Addition of oxygen to the nitrogen gas reduced the specific contact
resistances (ρc) and resitivities of the p-GaN epilayers (ρs) of the contacts after annealing at temperatures of 500–600°C. The microstructural analysis at the p-GaN/metal interfaces
did not detect the heterostructural intermediate semiconductor layer at the GaN/metal interfaces. The reason for reduction
of both the ρc and ρs values by the oxygen gas addition was believed to be due to formation of the p-GaN epilayer with high hole concentrations,
caused by removal of hydrogen atoms which bonded with Mg atoms. 相似文献
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在CZ法晶体生长工艺中引入磁场是一门新技术,它使得生长高质量大直径单晶成为可能。本文介绍了纵向磁场和横向磁场对GaAs晶体质量的影响,重点介绍了对熔体中的温度波动、晶体中的生长条纹、EL2和电阻率分布等的影响。这门技术目前在国际上得到了广泛的应用。 相似文献
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Calculations of specific contact resistance as a function of doping and barrier height were performed for p-type GaN. These
calculations took into account two valence bands, each with different effective masses, and show that at low doping, the heavy
hole band accounts for most of the conduction, whereas at heavier doping, the light hole band dominates conduction. These
calculations also indicate the barrier height for typical contacts to p-GaN is between 0.75 eV and 1 eV. Specific contact
resistance measurements were made for oxidized Ni/Au, Pd, and oxidized Ni/Pd ohmic contact metal schemes to p-GaN. The Ni/Pd
contact had the lowest specific contact resistance, 6×10−4 Ω cm2. Auger sputter depth profile analysis showed some Ni diffused away from the GaN surface to the contact surface with the bulk
of the Pd located in between two areas of Ni. Both Ni and Pd interdiffused with the GaN at the semiconductor surface. The
majority of the oxygen observed was with the Ni as NiO. Angle-resolved-x-ray photoelectron spectroscopy (AR-XPS) analyses
showed the formation of predominantly NiO and PdO species, with higher Ni and Pd oxides at the contact surface. 相似文献
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氧化对 GaN 基LED透明电极接触特性的影响 总被引:5,自引:5,他引:0
研究了热退火对InGaN/GaN 多量子阱LED的Ni/Au-p-GaN欧姆接触的影响.发现在空气和 N2气氛中交替地进行热退火的过程中Ni/Au接触特性显示出可逆现象. Ni/Au-p-GaN接触的串联电阻在空气中随合金化时间逐渐减小,在随后的 N2 中的热退火后会使该串联电阻增加,但在空气中再次热退火能使接触特性得到恢复.同时对Ni/Au-p-GaN 接触在空气中合金化过程中的层反转的成因进行了讨论. 相似文献
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对掺杂GaN的湿法刻蚀研究进行了总结,回顾了不同的湿法刻蚀技术,包括传统的酸碱化学刻蚀和电化学刻蚀。从掺杂GaN的生长过程、表面化学组分和光电性质出发,深入地分析了湿法刻蚀的特性,对比了不同刻蚀方法的原理和效果。考虑到p-GaN的表面氧化层比较厚,接触电阻较大,能带向下弯曲不能进行光增强湿法刻蚀,重点阐述了p-GaN的传统湿法刻蚀和n-GaN的紫外光增强湿法刻蚀技术。与传统化学刻蚀相比,光增强湿法刻蚀具有更为广阔的前景。结合GaN基半导体器件的制作,对湿法刻蚀的主要应用进行了较为详细的归纳。目前,湿法刻蚀和干法刻蚀可以有效结合。将来湿法刻蚀有希望代替干法刻蚀。 相似文献