Dalapati, P., Arulkumaran, S., Xie, H., & Ng, G. I. (2025). Improved device performance in in situ SiNx/AlN/GaN MIS-HEMTs with ex situ Al2O3 passivation at elevated temperatures. Applied Physics Letters, 126(11). https://doi.org/10.1063/5.0252966
Abstract:
In the present work, the role of ex situ Al2O3 passivation in in situ SiNx/AlN/GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs) to boost device performance and thermal stability during the high-temperature operations has been thoroughly investigated. At room temperature (RT), the MIS-HEMT fabricated with an atomic layer deposited (ALD)-Al2O3 (MIS-HEMT B) exhibits higher maximum drain current (Id,max), peak transconductance (gm,max), and lower subthreshold slope (SS) and gate leakage current compared to MIS-HEMT A fabricated without ex situ Al2O3, signifying the effectiveness of the ALD-Al2O3 layer to passivate severe surface states. Of note, when the temperature rises from 298 to 423 K, the values of Id,max and gm,max decrease noticeably, while SS and gate leakage current increase considerably in both MIS-HEMTs A and B. However, MIS-HEMT B demonstrates a lower degradation rate in various device properties at 423 K compared to MIS-HEMT A, implying that ALD-Al2O3 passivation improves thermal stability. Additionally, ALD-Al2O3 passivation reduces the interface state density from 7.48 × 1012 to 5.3 × 1012 cm−2 eV−1, highlighting its critical role in improving overall device performance.
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Funding Info:
This research / project is supported by the Agency for Science, Technology and Research - RIE2025 Manufacturing, Trade, and Connectivity Programmatic Fund
Grant Reference no. : M21K6b0134
This research / project is supported by the National Research Foundation, Singapore and Agency for Science, Technology and Research - RIE2025 White Space-Manufacturing, Trade, and Connectivity funding
Grant Reference no. : M23WSNG001
Description:
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Dalapati, P., Arulkumaran, S., Xie, H., & Ng, G. I. (2025). Improved device performance in in situ SiNx/AlN/GaN MIS-HEMTs with ex situ Al2O3 passivation at elevated temperatures. Applied Physics Letters, 126(11) and may be found at https://doi.org/10.1063/5.0252966