This study comprehensively investigates the threshold voltage (Vth) instability of AlGaN/GaN MIS-HEMTs under semi-on state conditions. The effects of various temperatures and drain biases are studied. Under semi-on bias conditions, a significant negative Vth shift up to −1.0 V is observed in MIS-HEMTs with 10-nm in-situ SiN gate dielectrics, whereas Schottky HEMTs exhibit a negligible Vth shift. A gate current analysis, comparing the MIS-HEMT with the source grounded versus floating, suggests that hot electrons induce generation of holes under the semi-on state. TCAD simulations corroborate that the high electric field across the channel of the MIS-HEMT induce hot electrons and hole generation under the semi-on state; dynamic interaction of hot electrons and holes with the gate SiN/AlGaN interfacial states leads to bias temperature instability (BTI) of the Vth of the MIS-HEMT. These findings suggest that optimizing the gate dielectric and its interface with the top barrier is crucial to improve the semi-on state stability of radio-frequency (RF) MIS-HEMTs.
Tsai, M-C, Kuo, Y-C, Yu, H, de Almeida Braga, N, Yang, Y, Lin, T-H, Fang, J, Lin, W-T, Navolotskaia, A, O'Sullivan, B, Rathi, A, Gupta, A, Yadav, S, Alian, A, Peralagu, U, Parvais, B, Collaert, N & Wu, T-L 2025, 'Threshold Voltage Bias Temperature Instability of RF MIS-HEMTs and Schottky HEMTs Under Semi-On State Stress', IEEE TRANSACTIONS ON ELECTRON DEVICES, vol. 72, no. 10, pp. 5359-5365. https://doi.org/10.1109/TED.2025.3600561
Tsai, M.-C., Kuo, Y.-C., Yu, H., de Almeida Braga, N., Yang, Y., Lin, T.-H., Fang, J., Lin, W.-T., Navolotskaia, A., O'Sullivan, B., Rathi, A., Gupta, A., Yadav, S., Alian, A., Peralagu, U., Parvais, B., Collaert, N., & Wu, T.-L. (2025). Threshold Voltage Bias Temperature Instability of RF MIS-HEMTs and Schottky HEMTs Under Semi-On State Stress. IEEE TRANSACTIONS ON ELECTRON DEVICES, 72(10), 5359-5365. https://doi.org/10.1109/TED.2025.3600561
@article{29f29544dd2d4f178967a895f5cac6cf,
title = "Threshold Voltage Bias Temperature Instability of RF MIS-HEMTs and Schottky HEMTs Under Semi-On State Stress",
abstract = "This study comprehensively investigates the threshold voltage (Vth) instability of AlGaN/GaN MIS-HEMTs under semi-on state conditions. The effects of various temperatures and drain biases are studied. Under semi-on bias conditions, a significant negative Vth shift up to −1.0 V is observed in MIS-HEMTs with 10-nm in-situ SiN gate dielectrics, whereas Schottky HEMTs exhibit a negligible Vth shift. A gate current analysis, comparing the MIS-HEMT with the source grounded versus floating, suggests that hot electrons induce generation of holes under the semi-on state. TCAD simulations corroborate that the high electric field across the channel of the MIS-HEMT induce hot electrons and hole generation under the semi-on state; dynamic interaction of hot electrons and holes with the gate SiN/AlGaN interfacial states leads to bias temperature instability (BTI) of the Vth of the MIS-HEMT. These findings suggest that optimizing the gate dielectric and its interface with the top barrier is crucial to improve the semi-on state stability of radio-frequency (RF) MIS-HEMTs.",
keywords = "GaN radio-frequency (RF) MIS-HEMT, hot electron injection, impact ionization, Vth instability",
author = "Meng-Che Tsai and Ying-Chun Kuo and Hao Yu and {de Almeida Braga}, Nelson and Yi Yang and Tzu-Heng Lin and Jingtian Fang and Wei-Tung Lin and Anna Navolotskaia and Barry O'Sullivan and Aarti Rathi and Amratansh Gupta and Sachin Yadav and AliReza Alian and Uthayasankaran Peralagu and Bertrand Parvais and Nadine Collaert and Tian-Li Wu",
note = "Publisher Copyright: {\textcopyright} 1963-2012 IEEE.",
year = "2025",
month = aug,
day = "28",
doi = "10.1109/TED.2025.3600561",
language = "English",
volume = "72",
pages = "5359--5365",
journal = "IEEE TRANSACTIONS ON ELECTRON DEVICES",
issn = "0018-9383",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "10",
}