Abstract
The relaxation of tensile stresses in AlGaN layers grown on GaN/(0001)sapphire by facet-controlled epitaxial lateral overgrowth is reported. It is shown that a-type misfit dislocations are introduced at inclined {11 (2) over bar2} AlGaN/GaN interfaces, with strong evidence for a half-loop nucleation and glide mechanism driven by shear stresses present on the (0001) slip plane. In addition to relieving misfit stresses, these dislocations introduce grain rotations of up to 10(-2) rad across the AlGaN/GaN boundaries, leading to tilt boundaries at the meeting front between laterally growing wings and between regions growing in the lateral and [0001] directions. The effects of these processes on the defect density in subsequent layers are examined.
Translated title of the contribution | The generation of misfit dislocations in facet-controlled growth of AlGaN/GaN films |
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Original language | English |
Pages (from-to) | 4923 - 4925 |
Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 85 (21) |
DOIs | |
Publication status | Published - 22 Nov 2004 |