Nanotribological Characteristics of the Al Content of Al<sub>x</sub>Ga<sub>1−x</sub>N Epitaxial Films

The nanotribological properties of aluminum gallium nitride (Al<sub>x</sub>Ga<sub>1−x</sub>N) epitaxial films grown on low-temperature-grown GaN/AlN/Si substrates were investigated using a nanoscratch system. It was confirmed that the Al compositions played an important role,...

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Bibliographic Details
Published in:Nanomaterials
Main Authors: Hua-Chiang Wen, Ssu-Kuan Wu, Cheng-Wei Liu, Jin-Ji Dai, Wu-Ching Chou
Format: Article
Language:English
Published: MDPI AG 2023-10-01
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Online Access:https://www.mdpi.com/2079-4991/13/21/2884
Description
Summary:The nanotribological properties of aluminum gallium nitride (Al<sub>x</sub>Ga<sub>1−x</sub>N) epitaxial films grown on low-temperature-grown GaN/AlN/Si substrates were investigated using a nanoscratch system. It was confirmed that the Al compositions played an important role, which was directly influencing the strength of the bonding forces and the shear resistance. It was verified that the measured friction coefficient (μ) values of the Al<sub>x</sub>Ga<sub>1−x</sub>N films from the Al compositions (where x = 0.065, 0.085, and 0.137) were in the range of 0.8, 0.5, and 0.3, respectively, for Fn = 2000 μN and 0.12, 0.9, and 0.7, respectively, for Fn = 4000 μN. The values of μ were found to decrease with the increases in the Al compositions. We concluded that the Al composition played an important role in the reconstruction of the crystallites, which induced the transition phenomenon of brittleness to ductility in the Al<sub>x</sub>Ga<sub>1−x</sub>N system.
ISSN:2079-4991