Design and Optimization of Self‐Isolation GaN HEMT with Lateral‐Polarity‐Structure
Design and Optimization of Self‐Isolation GaN HEMT with Lateral‐Polarity‐Structure
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横向极性结构自隔离GaN HEMT的设计与优化
DOI：
10.1002/pssr.202200436
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
J. Ye
中科院分区：
文献类型：
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作者：
Yijun Dai;Zi;Tian Luo;Zhehan Yu;Li Chen;Wei Guo;J. Ye
在本文中，通过并入横向极性结构（LPS），证明了AlGaN/GaN高电子迁移率晶体管（HEMT）中无工艺损伤的极化诱导自隔离。将LPS掺入到AlGaN/GaN异质结中表明，在III极异质结中形成了2D电子气（2DEG），但在N极异质结中耗尽。揭示了III极性和N极性域边界之间的3.5 eV的大横向势垒高度，并且证明缓冲泄漏是导致隔离特性减弱的原因。为了抑制缓冲区泄漏，AlGaN缓冲区对漏电流的影响进行了全面的研究。与纯GaN膜和AlGaN/GaN异质结相比，AlGaN/GaN/Al0.2Ga0.8N异质结中的两端隔离漏电流大大降低了约9个数量级，实验证实低至10−11 A。将LPS掺入AlGaN/GaN异质结中，通过消除隔离泄漏路径，提供了具有优异器件性能的新型平面隔离技术。
Herein, polarization‐induced self‐isolation free from process damages in AlGaN/GaN high‐electron‐mobility transistor (HEMT) by the incorporation of lateral‐polarity structure (LPS) is demonstrated. The incorporation of LPS into the AlGaN/GaN heterojunction shows that 2D electron gas (2DEG) is formed in the III‐polar heterojunction but depleted in the N‐polar counterpart. A large lateral barrier height of 3.5 eV between the III‐polar and N‐polar domain boundary is revealed and buffer leakage is proved to be responsible for the weakened isolation characteristics. To suppress the buffer leakage, the influence of the AlGaN buffer on the leakage current is comprehensively investigated. Compared to pure GaN film and AlGaN/GaN heterojunction, two‐terminal isolation leakage current in AlGaN/GaN/Al0.2Ga0.8N heterojunction is greatly reduced by about nine orders of magnitude to as low as 10−11 A as experimentally confirmed. The incorporation of LPS into AlGaN/GaN heterojunction provides a novel planar isolation technique with excellent device performance by eliminating the isolation leakage path.