【Substrate Papers】A Review of GaN HEMTs on β-Ga₂O₃ Substrates for RF and Power Electronics Applications

      Researchers from SR University have published a dissertation titled " A Review of GaN HEMTs on β-Ga₂O₃ Substrates for RF and Power Electronics Applications " in Micro and Nanostructures.

Abstract

      The combination of Gallium Nitride (GaN) and Beta Gallium-Oxide (β-Ga₂O₃) has proven to be a promising route to the next-generation HEMTs aiming at HP & RF applications. This integration is significant due to UWBG (Ultra-Wide-Band-gap) of ∼4.9eV, low lattice mismatch with GaN, E_C (high critical electric field) ∼8 MV/cm. This article presents a comprehensive discussion on the new developments in the GaN-HEMTs, the effect of substrate choice, buffer and barrier layer design, addition of BB (back-barrier) and spacer layer optimization on the overall performance & reliability of the devices. The effectiveness & reliability of GaN-HEMTs varies greatly with the inclusion of gate FP (field plate), nucleation layers, and passivation layers all of which increase electric field distribution, thermal stability, and regulation of surface charges. The gate recessing, gate geometry and graded barrier engineering are few examples of structural improvements that have been broadly used to improve transconductance (g_m), threshold voltage control, V_br (breakdown voltage) and RF parameters. GaN-HEMTs have better material properties than traditional semiconductor devices, including wide bandgap, high breakdown strength and electron mobility. These benefits result in better power management, frequency performance and increased efficiency that allows them to be applied in high end technology like radar, satellite communication, microwave and millimeter-wave systems, wireless networks, aerospace and military technology.

DOI：

https://doi.org/10.1016/j.micrna.2026.208736