Investigation of Interlayer Dielectric in BaTiO3/III‐Nitride Transistors

This study investigated the impact of varying the thickness of the Al2O3 interlayer dielectric on the electrical characteristics of BaTiO3/III‐Nitride transistors. The findings revealed that a minimum thickness of 8 nm for the Al2O3 layer is crucial to maintain high device performance and protect against sputtering‐induced damage during BaTiO3 deposition. The fabricated BaTiO3/Al2O3/AlGaN/GaN HEMTs exhibited exceptional electrical properties, including a maximum current density of 700 mA/mm, an on‐resistance of 5 Ω·mm, an ION/IOFF ratio of 107, a subthreshold slope of 119 mV/dec, and significantly reduced gate leakage current. The devices with the optimal 8 nm Al2O3 thickness demonstrated excellent agreement between theoretical and experimental values for effective mobility, achieving a value of 1188 cm2/V·s at a 2DEG density of 1013 cm‐2. Furthermore, the study confirmed that increasing the Al2O3 thickness also improved the quality of interface charge density, as evidenced by the results obtained from capacitance‐voltage (CV) measurements. These findings highlight the critical role of controlling the Al2O3 thickness in optimizing the electrical characteristics and overall performance of BaTiO3/III‐Nitride transistors.This article is protected by copyright. All rights reserved.