【Device Papers】A comparative high-temperature electrical study of single crystal and amorphous ZnGa₂O₄ as a gate dielectric in β-Ga₂O₃ MOSCAP Devices

      Researchers from the Texas State University have published a dissertation titled "A comparative high-temperature electrical study of single crystal and amorphous ZnGa₂O₄ as a gate dielectric in β-Ga₂O₃ MOSCAP Devices" in Materials Research Bulletin.

Abstract

      Spinel ZnGa₂O₄, a wide bandgap semiconductor with high breakdown voltage and thermal stability, is promising for power electronics. Amorphous and single-crystal ZnGa₂O₄ thin films were deposited on n-type β-Ga₂O₃ substrates. Au/ZnGa₂O₄/β-Ga₂O₃ MOSCAPs were evaluated up to 300 °C. Single-crystal (111) ZnGa₂O₄ showed a 5.06 eV bandgap, confirmed by XPS. Reverse leakage current rose by nearly three orders of magnitude from room temperature to 300 °C. Poole–Frenkel (PF) analysis revealed a 0.58 V trap and 0.47–0.23 eV activation energy. Amorphous ZnGa₂O₄ films (5.11 eV bandgap) exhibited leakage current increases of five orders of magnitude and PF traps at 0.6 V with 0.45–0.43 eV activation energies. C–V analysis showed significant flat-band voltage shifts and slope changes in both devices, indicating rising oxide and interface trap densities with temperature.

DOI：

https://doi.org/10.1016/j.materresbull.2025.113791