Thermal stability of epitaxial α-Ga2O3 and (Al,Ga)2O3 layers on m-plane sapphire
Abstract
Here, we have explored the thermal stability of α-(Al,Ga)2O3 grown by the molecular-beam epitaxy on m-plane sapphire under high-temperature annealing conditions for various Al compositions (i.e., 0%, 46%, and 100%). Though uncapped α-Ga2O3 undergoes a structural phase transition to the thermodynamically stable β-phase at high temperatures, we find that an aluminum oxide cap grown by atomic layer deposition preserves the α-phase. Unlike uncapped α-Ga2O3, uncapped α-(Al,Ga)2O3 at 46% and 100% Al content remain stable at high temperatures. We quantify the evolution of the structural properties of α-Ga2O3, α-(Al,Ga)2O3, and α-Al2O3 and the energy bandgap of α-Ga2O3 up to 900 °C. Throughout the anneals, the α-Ga2O3 capped with aluminum oxide retains its high crystal quality, with no substantial roughening.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 09, 2021
- Source ID
- 10.1063/5.0064278
Entities
People
- Andrew J. Green
- Celesta S. Chang
- D. A. Muller
- Darrell G. Schlom
- Debdeep Jena
- Derek Rowe
- Huili Grace Xing
- Jonathan P. McCandless
- Joseph Casamento
- K. Nomoto
- Katie R. Gann
- Kelson D. Chabak
- Michael O Thompson
- Patrick Vogt
- Riena Jinno
- Shao-Ting Ho
- Vladimir Protasenko
- Wenshen Li
- Yong-Jin Cho
Organizations
- Air Force Office of Scientific Research
- Air Force Research Laboratory
- Cornell University
- Leibniz Institute for Crystal Growth
- National Science Foundation