【Device Papers】Self-Heating Effects and Electron Mobility Dynamics in Sub-10 nm β-(AlₓGa₁₋ₓ)₂O₃/Ga₂O₃ Modulation Doped TMG-FET

      Researchers from the King Khalid University have published a dissertation titled "Self-Heating Effects and Electron Mobility Dynamics in Sub-10 nm β-(Al_xGa_1−x)₂O₃/Ga₂O₃ Modulation Doped TMG-FET" in Journal of Electronic Materials.

Abstract

      This study explores the influence of self-heating on both thermal and electronic transport behavior in sub-10 nm β-(Al_xGa_1−x)₂O₃/Ga₂O₃ tri-metal gate field-effect transistors (TMG-FETs). The devices were fabricated using a novel approach that integrates plasma-assisted molecular beam epitaxy (MBE) with ultrahigh vacuum deposition, yielding a structure composed of a 230 nm Ga₂O₃ active layer and a 10.0 nm Al₂O₃ insulating barrier. Results reveal a substantial decline in thermal conductivity as the Ga₂O₃ channel thickness falls below 10.0 nm, leading to intensified phonon scattering, elevated channel temperatures, and reduced electron mobility. Additionally, the study examines the impact of inter-metal layer thickness and channel geometry on thermal dissipation and carrier transport. These insights underscore the suitability of β-(Al_xGa_1−x)₂O₃/Ga₂O₃ TMG-FETs for high-performance biosensing, driven by their scalable design, strong surface charge sensitivity, and superior electrical behavior. Overall, the findings highlight the importance of structural optimization and advanced thermal management strategies to enhance the reliability and operational efficiency of ultra-scaled TMG-FETs for high-power applications.

DOI：

https://doi.org/10.1007/s11664-025-12128-7