Liu, S., Zhuang, Y., Li, H., Cui, P., Xie, Q., Wang, Y., Xie, H., Ranjan, K., & Ng, G. I. (2025). Analysis of Leakage Channel with Different Al Composition back Barriers in AlN/GaN High‐Electron‐Mobility Transistors on Silicon. Physica Status Solidi (a). Portico. https://doi.org/10.1002/pssa.202400983
Abstract:
This study investigates the effect of different Al compositions in the back‐barrier (BB) materials on the off‐state leakage characteristics of AlN/GaN/AlxGaN high‐electron‐mobility transistors (HEMTs) on silicon substrates. The position of the N‐type parasitic channel within the epitaxial material is further validated. Electrical performance measurements of AlN/GaN/AlGaN HEMTs with varying isolation depths are conducted, and parasitic channels in the unintentionally doped AlGaN BBs are confirmed through isolation leakage and capacitance tests. Transmission line model results reveal that the parasitic channel is an N‐type channel with a sheet resistance of 7078.4 Ω sq−1. Simulations show that the Al composition in the BB layer influences the position of the N‐type parasitic channel. As the Al composition increases to 15%, the parasitic channel contracts from the BB layer into the GaN channel layer. Isolation leakage tests on Al0.2GaN and AlN BBs, with the isolation depth controlled at the interface between the channel and the BB layers, yield leakage currents of 3.9 × 10−4 and 2 × 10−7 mA mm−1, respectively.
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Publisher Copyright
Funding Info:
This research / project is supported by the National Research Foundation, and Agency for Science, Technology and Research - RIE2025 Manufacturing, Trade & Connectivity (MTC) Industry Alignment Fund Pre-Positioning (IAF-PP)
Grant Reference no. : M22L3a0112
This research / project is supported by the National Research Foundation, and Agency for Science, Technology and Research - RIE2025 White Space-Manufacturing, Trade, and Connectivity Funding
Grant Reference no. : M23WSNG001
Description:
This is the peer reviewed version of the following article: Liu, S., Zhuang, Y., Li, H., Cui, P., Xie, Q., Wang, Y., Xie, H., Ranjan, K., & Ng, G. I. (2025). Analysis of Leakage Channel with Different Al Composition back Barriers in AlN/GaN High‐Electron‐Mobility Transistors on Silicon. Physica Status Solidi (a). Portico. https://doi.org/10.1002/pssa.202400983, which has been published in final form at https://doi.org/10.1002/pssa.202400983. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.