【Epitaxy Papers】Performance Enhancement of MOCVD Grown β-Ga₂O₃ MOSFETs on Silicon Substrates via AlN Buffer Layer

      Researchers from the National Chi Nan University have published a dissertation titled "Performance Enhancement of MOCVD Grown β-Ga₂O₃ MOSFETs on Silicon Substrates via AlN Buffer Layer" in ACS Applied Electronic Materials.

Abstract

      β-Ga₂O₃-based MOSFETs hold significant promise for high-power device applications due to their wide band gap and high breakdown voltage. However, the direct integration of β-Ga₂O₃ on silicon substrates is challenged by lattice and thermal expansion mismatches, which degrade device performance. This work explores the use of an aluminum nitride (AlN) buffer layer to mitigate these issues, offering improved structural quality and enhanced electrical performance. We demonstrate the growth of β-Ga₂O₃/AlN/Si films using metal–organic chemical vapor deposition, where the introduction of an AlN buffer layer significantly promotes the (−201) β-Ga₂O₃ orientation, which lacks in β-Ga₂O₃/Si films, as confirmed by XRD analysis. The presence of an AlN buffer layer is evidenced using SEM micrographs and XPS depth profile. The β-Ga₂O₃/AlN/Si MOSFETs exhibit a maximum drain current (I_DS) of 52 mA/mm, remarkable drain current on/off ratio of ∼10⁸ and a breakdown voltage (V_br) of 178 V, surpassing the performance of β-Ga₂O₃/Si MOSFETs, which showed an I_DS of 45 mA/mm and a V_br of 106 V. These results underscore the potential of AlN buffer layers in advancing the performance and reliability of β-Ga₂O₃-based transistors on silicon, paving the way for next-generation power electronics.

DOI：

https://doi.org/10.1021/acsaelm.4c02006