Room-Temperature Organic Passivation for GaN-on-Si HEMTs With Improved Device Stability

• Published in: IEEE transactions on electron devices 2024-03, Vol.71 (3), p.1-5
• Main Authors: Zhang, Haochen, Hu, Kunpeng, Sun, Yue, Yang, Lei, Huang, Zhe, Guo, Yifu, Deng, Junyang, Liang, Kun, Xing, Zhanyong, Wang, Hu, Zhang, Mingshuo, Chen, Yao, Guo, Shiping, Li, Mengmeng, Sun, Haiding
• Format: Article
• Language: English
• Subjects: Device stability; Electronic systems; Gallium nitrides; GaN-on-Si; HEMTs; High electron mobility transistors; High temperature; high-electron-mobility transistors (HEMT); Hysteresis; Leakage current; Logic gates; Low level; MODFETs; organic passivation; Passivation; Passivity; Room temperature; Semiconductor devices; Spin coating; Stability; Stress; Thermal stability
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2023.3280863

In this work, we report an effective room-temperature passivation strategy for GaN-on-Si high-electron-mobility transistors (HEMTs) to improve device stability by introducing a spin-coated CYTOP organic passivation layer. This CYTOP coating can suppress the interface states of the devices to a low level of \sim 10 ^{\text{12}} cm ^{-\text{2}}\cdot eV ^{-\text{1}} at a shallow energy trap of \sim 0.30 eV. As a result, improved device stability is realized, featuring reduced leakage current, smaller voltage hysteresis, reduced current collapse, and mitigated device degradation after long-term electrical stress. Besides, it is found that the CYTOP-passivated HEMT can operate with stable rectification behavior under an elevated temperature of 250 ^{\circ} C, confirming the high-temperature robustness of this organic passivation. These results highlight the potential of such room-temperature passivation strategy for further applications in electronic systems under complex conditions and harsh environments.