High-resolution transmission electron microscopy (HRTEM) observation of dislocation structures in AlN thin films

Abstract

The structure and configuration of threading dislocations (TDs) in AlN films grown on (0001) sapphire by metal–organic vapor phase epitaxy (MOVPE) were characterized by high-resolution transmission electron microscopy (HRTEM). It was found that the TDs formed in the films were mainly the perfect edge dislocations with the Burgers vector of b = 1/3〈11¯20〉. The majority of the edge TDs were not randomly formed but densely arranged in lines. The arrays of the edge TDs were mainly observed on the {11¯20} and {10¯10} planes. These two planes showed different configurations of TDs. TD arrays on both of these planes constituted low-angle boundaries. We suggest that these TDs are introduced to compensate for slight misorientations between the subgrains during the film growth.

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Acknowledgments

This work was supported in part by the Grant-in-Aid for Scientific Research on Priority Areas “Nano Materials Science for Atomic-Scale Modification” (No. 19053001) from the Ministry of Education, Culture, Sports and Technology (MEXT) of Japan. Y.T. is supported as a Japan Society for the Promotion of Science (JSPS) research fellow. N.S. acknowledges support from PRESTO, Japan Science and Technology Agency.

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Correspondence to Yuichi Ikuhara.

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Tokumoto, Y., Shibata, N., Mizoguchi, T. et al. High-resolution transmission electron microscopy (HRTEM) observation of dislocation structures in AlN thin films. Journal of Materials Research 23, 2188–2194 (2008). https://doi.org/10.1557/JMR.2008.0265

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