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arXiv · 2105.03741

Assessment of the (010) $β$-Ga$_2$O$_3$ Surface and Substrate Specification

Michael A. Mastro·Charles R. Eddy, Jr.·Marko J. Tadjer·Jennifer K. Hite·Jihyun Kim·Stephen J. Pearton
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Abstract

Recent breakthroughs in bulk crystal growth of the thermodynamically stable beta phase of gallium oxide ($β$-Ga$_2$O$_3$) have led to the commercialization of large-area beta-Ga$_2$O$_3$ 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) $β$-Ga$_2$O$_3$ 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 $β$-Ga$_2$O$_3$ is presented and recommendations are presented for standardizing (010) substrates to account for and control the larger-scale ridge formation.

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Michael A. Mastro, Charles R. Eddy, Jr., Marko J. Tadjer, Jennifer K. Hite, Jihyun Kim, Stephen J. Pearton. 2021-05-08. Assessment of the (010) $β$-Ga$_2$O$_3$ Surface and Substrate Specification. https://doi.org/10.1116/6.0000725

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