Improved Electrical Performance of Metal-Oxide-Semiconductor High-Electron-Mobility Transistors (MOS-HEMTs) Using Al2O3/HfO2 Stacked Gate Dielectrics

Seokhyun Han; Jihoon Lee; Hyeonwoo Hwang; Jinsung Park; Bohyeon Kim; Junmo Yang; Younghun Han; Juneo Song; Yoon Seok Kim

doi:10.3740/MRSK.2026.36.2.70

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2026 Vol.36, Issue 2 Preview Page

Research Paper

Improved Electrical Performance of Metal-Oxide-Semiconductor High-Electron-Mobility Transistors (MOS-HEMTs) Using Al₂O₃/HfO₂ Stacked Gate Dielectrics Al₂O₃/HfO₂ 스택 구조의 게이트 산화막을 이용한 Metal-Oxide-Semiconductor High-Electron-Mobility Transistors (MOS-HEMTs) 전기적 특성 향상

27 February 2026. pp. 70-76

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Abstract

AlGaN/GaN high-electron-mobility transistors (HEMTs) are widely employed in power electronics and high-frequency systems because of their high-speed switching and high-power capabilities. However, conventional structures suffer from issues including mobility degradation and device deterioration at elevated temperatures, as well as current collapse and increased gate leakage under high-voltage operation. To address these issues, this work proposes metal-oxide-semiconductor HEMTs (MOS-HEMTs) incorporating an Al₂O₃/HfO₂ stacked gate dielectric. Al₂O₃ provides excellent chemical stability at the AlGaN interface, reducing interface trap density, while its wide bandgap suppresses electron tunneling and lowers gate leakage. In contrast, HfO₂ offers a high dielectric constant, improving oxide capacitance and enhancing charge control even at the same physical thickness. The stacked Al₂O₃/HfO₂ structure leverages the complementary advantages of both materials, enabling threshold voltage stabilization and effective suppression of leakage current. This design mitigates the thermal and electrical reliability concerns of conventional HEMTs and paves the way for high-performance GaN-based devices suited to next-generation high-speed, high-power applications such as artificial intelligence, 5G communication, and LiDAR systems.

Keywords

metal-oxide-semiconductor high-electron-mobility transistors

oxide barrier

high-k

stack

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Information

Publisher :Materials Research Society of Korea
Publisher(Ko) :한국재료학회
Journal Title :Korean Journal of Materials Research
Journal Title(Ko) :한국재료학회지
Volume : 36
No :2
Pages :70-76
Received Date : 2025-09-29
Revised Date : 2026-01-30
Accepted Date : 2026-01-30
DOI :https://doi.org/10.3740/MRSK.2026.36.2.70

Korean Journal of Materials Research ISSN:1225-0562(Print) 2287-7258(Online) 한국재료학회지

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