Origin of Strain in GaN Thin Films

TitleOrigin of Strain in GaN Thin Films
Publication TypeConference Paper
Year of Publication1996
AuthorsChristian F Kisielowski, Joachim Krüger, Michael SH Leung, Ralf Klockenbrink, Hiroaki Fujii, Tadeusz Suski, Sudhir G Subramanya, Joel W Ager, III, Michael D Rubin, Eicke R Weber
EditorJoachim Krüger
Conference Name23rd International Conference on the Physics of Semiconductors
Conference LocationSingapore
Call NumberLBNL-39853

Photoluminescence measurements are used to determine the strain in GaN thin films grown by Molecular Beam Epitaxy. The strain which originates from growth on lattice mismatched substrates and from differences in thermal expansion coefficients is found to be greatly relaxed. Residual strains are shown to depend on the thickness of GaN buffer layers and the III/V flux ration during main layer growth. The results strongly suggest that the residual biaxial strain caused by the post-growth cooling can be modified by the incorporation of point defects during the main layer growth which introduce an additional hydrostatic strain field. The effect allows for strain engineering of GaN crystals.

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