a-Axis GaN/AlN/AlGaN Core-Shell Heterojunction Microwires as Normally Off High Electron Mobility Transistors
a-Axis GaN/AlN/AlGaN Core-Shell Heterojunction Microwires as Normally Off High Electron Mobility Transistors
复制标题
a轴 GaN/AlN/AlGaN 核壳异质结微线作为常断高电子迁移率晶体管
DOI：
10.1021/acsami.7b12986
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发表时间：
2017-11-29
影响因子：
9.5
通讯作者：
Li, Shuti
中科院分区：
文献类型：
--
作者：
Song, Weidong;Wang, Rapeng;Li, Shuti
基于微/纳米线的器件被认为是改善电子和光电应用的一条有前途的新途径，吸引了相当多的研究兴趣。然而，由于合成均匀核壳结构的适用策略以满足沿长度方向或高电子迁移率晶体管（HEMT）器件的电传输行为研究的要求，基于异质结线的电子器件的探索有限。在目前的工作中，通过金属有机化学气相沉积在图案化的硅衬底上合成了 GaN/AlN/AlGaN 核壳异质结微线，无需任何催化剂。合成的微丝具有低位错、尖锐且均匀的异质结界面。通过在异质结微线通道上制造 HEMT 来评估电传输性能。结果表明，以 1.4 V 的阈值电压、10(8) 的高开/关电流比、165 mS/mm 的跨导和 81 mV/dec 的低亚阈值摆幅实现了常关操作。常断操作可能归因于异质结半极性面的弱极化，这导致 2DEG 的约束较弱。
Micro/nanowire-based devices have been envisioned as a promising new route toward improved electronic and optoelectronic applications, which attracts considerable research interests. However, suffering from applicable strategies to synthesize uniform core-shell structures to meet the requirement for the investigations of electrical transport behaviors along the length direction or high electron mobility transistor (HEMT) devices, heterojunction wire based electronics have been explored limitedly. In the present work, GaN/AlN/AlGaN core-shell heterojunction microwires on patterned Si substrates were synthesized without any catalyst via metalorganic chemical vapor deposition. The as-synthesized microwires had low dislocation, sharp, and uniform heterojunction interfaces. Electrical transport performances were evaluated by fabricating HEMTs on the heterojunction microwire channels. Results demonstrated that a normally off operation was achieved with a threshold voltage of 1.4 V, a high on/off current ratio of 10(8), a transconductance of 165 mS/mm, and a low subthreshold swing of 81 mV/dec. The normally off operation may attribute to the weak polarization along semipolar facets of the heterojunction, which leads to weak constrain of 2DEG.