Study of Phase Transition in MOCVD Grown Ga2O3 from κ to β Phase by Ex Situ and In Situ Annealing
Abstract
We report the post-growth thermal annealing and the subsequent phase transition of Ga2O3 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 Ga2O3 epitaxial layer becomes conductive after annealing at 1000 °C. Furthermore, we demonstrate that in situ annealing can lead to a crack-free β-Ga2O3.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 13, 2021
- Source ID
- 10.3390/photonics8010017
Entities
People
- Honghyuk Kim
- Junhee Lee
- Kun He
- Lakshay Gautam
- Manijeh Razeghi
- Vinayak P. Dravid
- Xiaobing Hu
Organizations
- United States Air Force