Recent breakthroughs in bulk crystal growth of the thermodynamically stable beta phase of gallium oxide (β-Ga2O3) have led to the commercialization of large-area beta-Ga2O3 substrates with subsequent epitaxy on (010) substrates producing high-quality films. Still, metal-organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and processing of the (010) β-Ga2O3 surface are known to form sub-nanometer scale facets along the [001] direction as well as larger ridges with features perpendicular to the [001] direction. A density function theory calculation of the (010) surface shows an ordering of the surface as a sub-nanometer-scale feature along the [001] direction. Additionally, the general crystal structure of β-Ga2O3 is presented and recommendations are presented for standardizing (010) substrates to account for and control the larger-scale ridge formation.
@article{arxiv.2105.03741,
title = {Assessment of the (010) $\beta$-Ga$_2$O$_3$ Surface and Substrate Specification},
author = {Michael A. Mastro and Charles R. Eddy, and Marko J. Tadjer and Jennifer K. Hite and Jihyun Kim and Stephen J. Pearton},
journal= {arXiv preprint arXiv:2105.03741},
year = {2021}
}