【Substrate Papers】Effect of CF4 Plasma Treatment on β-Ga₂O₃ (001) Substrates for Enhanced Homoepitaxial Growth by MOCVD

      Researchers from the Chonnam National University have published a dissertation titled "Effect of CF₄ Plasma Treatment on β-Ga₂O₃ (001) Substrates for Enhanced Homoepitaxial Growth by MOCVD" in Materials Research Bulletin.

Abstract

      Recently, β-Ga₂O₃ has attracted considerable attention as an ultrawide-bandgap semiconductor owing to its large bandgap (∼4.9 eV), high breakdown field, and strong potential for next-generation power and optoelectronic devices. However, achieving high-quality homoepitaxial growth remains challenging due to interfacial strain, lattice imperfections, and surface-related effects. In this study, homoepitaxial β-Ga₂O₃ (001) films were grown on CF₄ plasma–treated β-Ga₂O₃ (001) substrates using metal–organic chemical vapor deposition (MOCVD). The CF₄-based inductively coupled plasma–reactive ion etching (ICP-RIE) treatment increased the substrate surface free energy by approximately 10 mJ/m² and reduced surface roughness, thereby enhancing precursor adsorption and promoting two-dimensional, layer-by-layer growth. As a result, both the crystal quality and surface morphology of the epitaxial films were significantly improved, and transmission electron microscopy confirmed the suppression of step-like interfacial distortions. These findings demonstrate that CF₄ plasma treatment effectively enhances homoepitaxial β-Ga₂O₃ (001) growth by minimizing interfacial defects and enabling more uniform epitaxy.

DOI：

https://doi.org/10.1016/j.materresbull.2025.113941