Dopant-free GaN/AlN/AlGaN radial nanowire heterostructures as high electron mobility transistors
Dopant-free GaN/AlN/AlGaN radial nanowire heterostructures as high electron mobility transistors
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DOI：
10.1021/nl060849z
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发表时间：
2006-07-12
期刊：
影响因子：
10.8
通讯作者：
Lieber, Charles M.
中科院分区：
文献类型：
--
作者：
Li, Yat;Xiang, Jie;Lieber, Charles M.
我们报道了无掺杂GaN/AlN/AlGaN径向纳米线异质结构的合理合成及其作为高电子迁移率晶体管（HEMT）的实现。径向纳米线异质结构的制备顺序壳生长后立即使用金属有机化学气相沉积（MOCVD）的纳米线伸长。透射电子显微镜（TEM）研究表明，GaN/AlN/AlGaN径向纳米线异质结构为无位错单晶。此外，使用横截面高角度环形暗场扫描透射电子显微镜（HAADF-STEM）的厚度和组成的各个AlN和AlGaN壳明确识别。对GaN/AlN/AlGaN和GaN纳米线进行的输运测量表明，未掺杂的GaN/AlN/AlGaN纳米线异质结构中存在电子气，并且在室温和5 K下的本征电子迁移率分别为3100 cm（2）/Vs和21 000 cm（2）/Vs。用ZrO 2半导体和金属顶栅制造的场效应晶体管显示出优异的栅极耦合，具有68 mV/dec的接近理想的亚阈值斜率，107的开/关电流比，以及500 mA/mm和420 mS/mm的按比例缩放的导通电流和导通电阻值。氮化物径向纳米线异质结构为纳米电子学开辟了新的机会，并提供了研究低维电子气物理的新平台。
We report the rational synthesis of dopant-free GaN/AlN/AlGaN radial nanowire heterostructures and their implementation as high electron mobility transistors (HEMTs). The radial nanowire heterostructures were prepared by sequential shell growth immediately following nanowire elongation using metal-organic chemical vapor deposition (MOCVD). Transmission electron microscopy (TEM) studies reveal that the GaN/AlN/AlGaN radial nanowire heterostructures are dislocation-free single crystals. In addition, the thicknesses and compositions of the individual AlN and AlGaN shells were unambiguously identified using cross-sectional high-angle annular darkfield scanning transmission electron microscopy (HAADF-STEM). Transport measurements carried out on GaN/AlN/AlGaN and GaN nanowires prepared using similar conditions demonstrate the existence of electron gas in the undoped GaN/AlN/AlGaN nanowire heterostructures and also yield an intrinsic electron mobility of 3100 cm(2)/Vs and 21 000 cm(2)/Vs at room temperature and 5 K, respectively, for the heterostructure. Field-effect transistors fabricated with ZrO2 dielectrics and metal top gates showed excellent gate coupling with near ideal subthreshold slopes of 68 mV/dec, an on/off current ratio of 107, and scaled on-current and transconductance values of 500 mA/mm and 420 mS/mm. The ability to control synthetically the electronic properties of nanowires using band structure design in III-nitride radial nanowire heterostructures opens up new opportunities for nanoelectronics and provides a new platform to study the physics of low-dimensional electron gases.