【Substrate Papers】Optimizing a novel green slurry by multifunctional pH regulators for ultra-smooth β-Ga₂O₃ (100) substrates via chemical mechanical polishing: experimental analysis, theoretical calculation and mechanistic insight

      Researchers from the Hebei University of Technology have published a dissertation titled "Optimizing a novel green slurry by multifunctional pH regulators for ultra-smooth β-Ga₂O₃ (100) substrates via chemical mechanical polishing: experimental analysis, theoretical calculation and mechanistic insight" in Applied Surface Science.

Abstract

      β-Ga₂O₃ is regarded as a highly promising fourth-generation semiconductor material due to its ultra-wide bandgap and high breakdown field strength. Nevertheless, a huge challenge has been discovered that lots of microcracks are caused due to the mechanical brittleness of β-Ga₂O₃ substrates during the CMP processing. Therefore, the effects of pH-modified SiO₂-based slurries with different pH regulators for β-Ga₂O₃ (1 0 0) CMP have been investigated. The results demonstrated that 2-amino-2-methyl-1-propanol (AMP) exhibited the most significant influence, increasing the removal rate of β-Ga₂O₃ (1 0 0) substrates to 1.45 μm/h and reducing the surface roughness (Sq) to 0.179 nm. The formation of complexes between AMP and [Ga(OH)₄]⁻ for the enhancement of chemical activity in CMP was verified by X-ray photoelectron spectroscopy (XPS) and theoretical calculation. This study proposes a scheme to effectively enhance the performance of β-Ga₂O₃ (1 0 0) CMP, which is potentially applicable to the processing of large-sized β-Ga₂O₃ in the future.

DOI：

https://doi.org/10.1016/j.apsusc.2026.165965