【Epitaxy Papers】Gallium flux induced etching of β-Ga₂O₃ in an LPCVD system

      Researchers from the Indian Institute of Technology Kanpur have published a dissertation titled "Gallium flux induced etching of β-Ga₂O₃ in an LPCVD system" in Journal of Vacuum Science & Technology A.

Abstract

      Gallium flux induced etching, a novel technique to etch β-Ga₂O₃, is demonstrated and studied in detail in a low pressure chemical vapor deposition (LPCVD) setup. Incoming gallium vapor flux and suboxide reaction rate at the β-Ga₂O₃ surface are key parameters which affect the β-Ga₂O₃ etching kinetics. Their influence on the etch rate is systematically studied, demonstrating a controlled etch rate up to ∼0.7 μm/h. To interpret the observed etch rate behavior, a particle conservation based analytical model is adapted and modified to suit the LPCVD configuration. Postetch surface morphology characterization shows vertical sidewalls in samples etched with SiO₂ masking while surface roughness of the etched surface is found to improve when etching is performed at higher temperatures. Flexibility to perform in situ etching in LPCVD, which is a low cost epitaxial β-Ga₂O₃ growth technique, could pave way for economical and improved device fabrication processes such as mesa isolation, gate recess, and contact regrowth.

DOI：

https://doi.org/10.1116/6.0004596