【Device Papers】Structural, electrical, and thermal characterization of homoepitaxial close-injection showerhead metalorganic chemical vapor deposition β-Ga₂O₃ enhancement-mode recessed-gate MOSFETs

      Researchers from the United States National Research Council have published a dissertation titled "Structural, electrical, and thermal characterization of homoepitaxial close-injection showerhead metalorganic chemical vapor deposition β-Ga₂O₃ enhancement-mode recessed-gate MOSFETs" in Journal of Vacuum Science & Technology A.

Abstract

      A systematic investigation was performed on the impact of the β-gallium oxide (Ga₂O₃) epitaxial buffer layer thickness grown by close-injection showerhead metalorganic chemical vapor deposition (CIS-MOCVD) on the film’s structural, electrical, and thermal characteristics. Varying thicknesses of unintentionally doped β-Ga₂O₃ epitaxial layers were grown by CIS-MOCVD on Fe-doped (010) β-Ga₂O₃ substrates, followed by a 10 nm β-Ga₂O₃ Si-doped layer with a Si concentration of 10¹⁹ cm⁻³. Gate-recessed lateral metal–oxide–semiconductor field-effect transistors were fabricated with these epilayer films. The device characteristics and secondary ion mass spectroscopy results highlighted the need for precise Si doping within the channel, as well as minimizing the Si accumulation at the epilayer-substrate interface for proper device operation. The results from positron annihilation spectroscopy did not indicate a strong correlation between the epilayer thickness and Ga-related vacancies, and the thermal conductivities of the epilayers were consistent with increasing thickness as shown in the device-level frequency-domain thermoreflectance analysis.

DOI：

https://doi.org/10.1116/6.0004176