【Epitaxy Papers】Rotational domains in heteroepitaxial β-Ga₂O₃ films grown by MOCVD

      Researchers from Institute of Electrical Engineering Slovak Academy of Sciences have published a dissertation titled " Rotational domains in heteroepitaxial β-Ga₂O₃ films grown by MOCVD " in 2026 International VLSI Symposium on Technology, Systems and Applications (VLSI TSA).

Abstract

      β-Ga₂O₃ is an emerging fourth-generation semiconductor material suitable for power-electronic device applications and deep UV optoelectronics owing to its ultrawide bandgap and high critical electric field. Heteroepitaxial growth of Ga₂O₃ is preferred to enable low-cost integration with large-scale substrates and materials with high thermal conductivity to achieve improved thermal performance of power-electronic devices. Commonly used foreign substrates, e.g., SiC and sapphire exhibit hexagonal surface symmetry giving rise to the formation of in-plane rotational domains (IRDs) in the （-201） β-Ga₂O₃ films. The presence of IRDs results in compromised crystal quality and degraded electrical properties. To overcome these issues, in this study we grew （-201） β-Ga₂O₃ films on the c-plane sapphire substrates with intentional off-cut towards the a-plane by the liquid-injection MOCVD technique to partially break the hexagonal surface symmetry of the sapphire substrate. Structural, electrical, and optical properties of grown Ga₂O₃ films were evaluated and depletion-mode MOSFET devices were prepared and their electrical properties were tested. In general, the quality of the β-Ga₂O₃ films was improved by the use of off-cut substrates. We also observed suppression of parasitic (310) domains, but no reduction of the （-201） IRDs.

DOI：

https://doi.org/10.1109/VLSITSA69131.2026.11527602