Thermal Stability and Phase Transformation of Conductive $\alpha$-$(\mathrm{Al}_{x}\mathrm{Ga}_{1-x})_{2}\mathrm{O}_{3}/\mathrm{Ga}_{2}\mathrm{O}_{3}$ Heterostructures on Sapphire Substrates

Botong Li; Shisong Luo; Jaeheon Jung; Bobby G. Duersch; Cheng Chang; Lucas Lau; Zonghao Zhang; Jianhua Li; Hunter Ellis; Imteaz Rahaman; Roy Byung Kyu Chung; Kai Fu; Yuji Zhao

arXiv · 2602.07591

Thermal Stability and Phase Transformation of Conductive $\alpha$-$(\mathrm{Al}_{x}\mathrm{Ga}_{1-x})_{2}\mathrm{O}_{3}/\mathrm{Ga}_{2}\mathrm{O}_{3}$ Heterostructures on Sapphire Substrates

Botong Li·Shisong Luo·Jaeheon Jung·Bobby G. Duersch·Cheng Chang·Lucas Lau·Zonghao Zhang·Jianhua Li·Hunter Ellis·Imteaz Rahaman·Roy Byung Kyu Chung·Kai Fu·Yuji Zhao

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Abstract

Thermal stability and phase transformation of conductive $\alpha$-$(\mathrm{Al}_{0.16}\mathrm{Ga}_{0.84})_{2}\mathrm{O}_{3}/\mathrm{Ga}_{2}\mathrm{O}_{3}$ heterostructures on sapphire substrates were investigated using in situ high-temperature X-ray diffraction (HT-XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Conductive $\alpha$-$(\mathrm{Al}_{0.16}\mathrm{Ga}_{0.84})_{2}\mathrm{O}_{3}/\mathrm{Ga}_{2}\mathrm{O}_{3}$ heterostructures with fluorine (F) doping were grown by mist chemical vapor deposition on sapphire substrates, achieving a Hall mobility of $28~\mathrm{cm^{2}\,V^{-1}\,s^{-1}}$ and an electron concentration of $1.4\times10^{20}~\mathrm{cm^{-3}}$. The heterostructures exhibited thermal stability up to approximately $550$--$

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Botong Li, Shisong Luo, Jaeheon Jung, Bobby G. Duersch, Cheng Chang, Lucas Lau, Zonghao Zhang, Jianhua Li, Hunter Ellis, Imteaz Rahaman, Roy Byung Kyu Chung, Kai Fu, Yuji Zhao. 2026-02-07. Thermal Stability and Phase Transformation of Conductive $\alpha$-$(\mathrm{Al}_{x}\mathrm{Ga}_{1-x})_{2}\mathrm{O}_{3}/\mathrm{Ga}_{2}\mathrm{O}_{3}$ Heterostructures on Sapphire Substrates. https://arxiv.org/abs/2602.07591

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