Study of phase transition in mocvd grown ga2 o3 from κ to β phase by ex situ and in situ annealing

Junhee Lee, Honghyuk Kim, Lakshay Gautam, Kun He, Xiaobing Hu, Vinayak P. Dravid, Manijeh Razeghi*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


We report the post-growth thermal annealing and the subsequent phase transition of Ga2 O3 grown on c-plane sapphire substrates by metal organic chemical vapor deposition (MOCVD). We demonstrated the post-growth thermal annealing at temperatures higher than 900 C under N2 ambience, by either in situ or ex situ thermal annealing, can induce phase transition from nominally metastable κ-to thermodynamically stable β-phase. This was analyzed by structural characterizations such as high-resolution scanning transmission electron microscopy and x-ray diffraction. The highly resistive as-grown Ga2 O3 epitaxial layer becomes conductive after annealing at 1000 C. Furthermore, we demonstrate that in situ annealing can lead to a crack-free β-Ga2 O3.

Original languageEnglish (US)
Article number17
Pages (from-to)1-8
Number of pages8
Issue number1
StatePublished - Jan 2021


  • Ga O
  • Phase transition
  • Thermal annealing
  • Thin films

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Instrumentation
  • Radiology Nuclear Medicine and imaging


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