【Device Papers】Electro-thermal Co-design of High-power Vertical β-Ga₂O₃ Schottky Diodes with High-permittivity Dielectric Field-plate

      Researchers from the Cornell University have published a dissertation titled "Electro-thermal Co-design of High-power Vertical β-Ga₂O₃ Schottky Diodes with High-permittivity Dielectric Field-plate" in Materials Science.

Abstract

      This work presents electrothermal co-design of vertical β-Ga₂O₃ Schottky barrier diodes (SBDs) to enhance both heat dissipation and high field management in high-power applications. Here, we demonstrate device-level thermal management tailored for two vertical β-Ga₂O₃ SBD structures that employed different edge termination techniques, such as field-plate and deep etch with sidewall field-plate, where the field-plate was formed with high-permittivity dielectric (BaTiO3). The localized thermal hot spots were detected at the Schottky contact edges near BaTiO3 dielectric based field-plate. However, a substantial reduction of the thermal hotspots was observed by forming the field-plate with BaTiO3 and thermally-conductive AlN insulator, where the AlN can effectively decrease Joule heating at interface and the high permittivity of BaTiO3 contributes to high field reduction. The deep etch and sidewall field-plate SBD structure further reduced accumulated heat and electric field near the critical anode edge by removing lateral depletion regions. We also analyzed thermal transport at dielectric/β-Ga₂O₃ interfaces using Landauer approach that revealed significantly higher thermal boundary conductance (TBC) enabled by AlN compared to BaTiO3, attesting to the superior heat dissipation ability by BaTiO3/AlN field-plate than the BaTiO3-only configuration. Experimental investigation with vertical metal/AlN/\b{eta}-Ga2O3 diodes also extracted a high breakdown field (~11 MV/cm) of AlN, significantly exceeding the material breakdown field of β-Ga₂O₃. This indicates that AlN can be an excellent choice for field-plate dielectric in vertical β-Ga₂O₃ SBDs to provide both enhanced high field sustainability and improved heat dissipation in high-power applications.

DOI：

https://doi.org/10.48550/arXiv.2508.11775