Dislocation reduction in GaN grown on nano-patterned templates


Using nano-holes patterned template as the substrate, TD density in GaN epitaxial layers has been effectively reduced.
By optimize the periodicity of the nano-hole pattern as well as the size and depth of holes, the TD density has been reduced to ~107 cm−2.
Cross-sectional TEM positively confirms the termination of TDs at positions of nano-hole voids.


A nano-holes patterned GaN-on-patterned sapphire substrate template has been developed to reduce the threading dislocation (TD) density in homoepitaxy GaN layer grown by plasma-assisted molecular beam epitaxy. The grown layers characterized by high resolution x-ray diffraction, photoluminescence, and cross-section transmission electron microscopy confirm that the TD density of GaN epilayer has been successfully reduced an order of magnitude to ~107 cm−2 by optimizing the depth and coverage area percentage of patterned nano-holes.


  • A1. Threading dislocations
  • A2. Nanoimprint lithography
  • A3. Molecular beam epitaxy

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