Normally-off AlGaN/GaN heterojunction field-effect transistors with in-situ AlN gate insulator
Normally-off AlGaN/GaN heterojunction field-effect transistors with in-situ AlN gate insulator
复制标题
具有原位 AlN 栅极绝缘体的常断 AlGaN/GaN 异质结场效应晶体管
DOI：
10.1088/1674-1056/ac7a0e
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
J. Ao
中科院分区：
文献类型：
--
作者：
T. Pu;S. Liu;X. Li;T. Wang;J. Du;L. Li;Liang He;X. Liu;J. Ao
研制了具有p-GaN帽层的AlGaN/GaN异质结场效应晶体管（HFET），其中原位生长的AlN层被用作栅极绝缘体。与SiNx栅绝缘层相比，AlN/p-GaN界面呈现出更明显的能带弯曲和更宽的耗尽区，这有助于阈值电压的正向移动。另外，AlN/p-GaN的导带偏移较大，有利于抑制栅漏电流，提高栅击穿电压。由于AlN层的引入，实现了阈值电压为4 V，栅摆幅为13 V的常关型p-GaN覆盖AlGaN/GaN HFET。此外，2DEG沟道中的场效应迁移率约为1500 cm 2·V-1·s-1，意味着良好的器件性能。
AlGaN/GaN heterojunction field-effect transistors (HFETs) with p-GaN cap layer are developed for normally-off operation, in which an in-situ grown AlN layer is utilized as the gate insulator. Compared with the SiN x gate insulator, the AlN/p-GaN interface presents a more obvious energy band bending and a wider depletion region, which helps to positively shift the threshold voltage. In addition, the relatively large conduction band offset of AlN/p-GaN is beneficial to suppress the gate leakage current and enhance the gate breakdown voltage. Owing to the introduction of AlN layer, normally-off p-GaN capped AlGaN/GaN HFET with a threshold voltage of 4 V and a gate swing of 13 V is realized. Furthermore, the field-effect mobility is approximately 1500 cm2⋅V−1⋅s−1 in the 2DEG channel, implying a good device performance.