Improved Ferroelectric Effects and Gate Controllability in Hf_0.5Zr_0.5O₂-Gated InAlGaN/GaN MIS-HEMTs Using ZrO₂ Seed Layers

Scaling of GaN high-electron-mobility transistors (HEMTs) frequently leads to increased gate leakage current and increased risk of device breakdown when subjected to high-speed switching, ultimately resulting in a reduction of the maximum drain current and output power density. These issues can be effectively mitigated by incorporating a dielectric layer beneath the gate in HEMTs. This study delves into the performance enhancement of Hf_0.5Zr_0.5O₂-gated InAlGaN/GaN metal–insulator–semiconductor (MIS) HEMTs that are grown on a ZrO₂ seed layer. The implementation of ferroelectric Hf_0.5Zr_0.5O₂(HZO) stacks has been shown to significantly reduce gate leakage current and stabilize threshold voltage shifts. Furthermore, the positive bias transconductance peak shift enhances the overall electrical stability of the device. Our findings underscore the potential of using ferroelectric stacks in InAlGaN/GaN HEMTs to achieve higher efficiency and operational stability. These advancements make Hf_0.5Zr_0.5O₂-gated HEMTs particularly suitable for advanced high-power and high-frequency applications, demonstrating their capacity to deliver superior performance under challenging conditions. The results of this study highlight the critical role of dielectric engineering in optimizing GaN-based devices, paving the way for future innovations in semiconductor technology.