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arXiv · 0804.1824

Recrystallization of epitaxial GaN under indentation

S. Dhara·C. R. Das·H. C. Hsu·Baldev Raj·A. K. Bhaduri·L. C. Chen·K. H. Chen·S. K. Albert·Ayan Ray
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Abstract

We report recrystallization of epitaxial (epi-) GaN(0001) film under indentation.Hardness value is measured close to 10 GPa, using a Berkovich indenter. Pop-in burst in the loading line indicates nucleation of dislocations setting in plastic motion of lattice atoms under stress field for the recrystallization process. Micro-Raman studies are used to identify the recrystallization process. Raman area mapping indicates the crystallized region. Phonon mode corresponding to E2(high) close to 570 cm-1 in the as-grown epi-GaN is redshifted to stress free value close to 567 cm-1 in the indented region. Evolution of A1(TO) and E1(TO) phonon modes are also reported to signify the recrystallization process.

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S. Dhara, C. R. Das, H. C. Hsu, Baldev Raj, A. K. Bhaduri, L. C. Chen, K. H. Chen, S. K. Albert, Ayan Ray. 2008-04-15. Recrystallization of epitaxial GaN under indentation. https://doi.org/10.1063/1.2907851

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