【Epitaxy Papers】Nitrogen doping of metal-organic chemical vapor deposition β-Ga₂O₃ using nitric oxide

      Researchers from the Agnitron Technology have published a dissertation titled "Nitrogen doping of metal-organic chemical vapor deposition β-Ga₂O₃ using nitric oxide" in Journal of Vacuum Science & Technology A.

Abstract

      We report on the use of nitric oxide (NO) diluted in nitrogen as a nitrogen dopant source for β-Ga₂O₃ grown by metal-organic chemical vapor deposition. The effects of the NO/N₂ flow rate, Ga precursor molar flow rate, and substrate temperature on nitrogen incorporation, doping controllability, and film growth rate were systematically investigated. Introducing small NO flows with O₂ increased film growth rates by ∼1.8–3.2× and enabled controllable nitrogen incorporation in films grown using triethylgallium and trimethylgallium precursors. Secondary ion mass spectrometry revealed a strong dependence of nitrogen incorporation on the NO flow rate, gallium supply, and substrate temperature. Nitrogen concentrations up to 6.5 × 10¹⁸ cm⁻³ were achieved, while NO/N₂ doping yielded substantially lower hydrogen incorporation, with N/H ratios up to ∼28. The resulting films exhibited excellent crystallinity, smooth morphology, and thermally activated conduction with activation energies ranging from ∼27 to 509 meV, depending on nitrogen concentration. These results establish NO as an alternative nitrogen source that enables controlled N doping with minimal hydrogen incorporation—offering a practical route for realizing semi-insulating β-Ga₂O₃ layers suitable for high-power electronic applications.

DOI：

https://doi.org/10.1116/6.0005191