Reduction of mechanical stresses in GaN/sapphire templates via formation of regular porous structure

Reduction of mechanical stresses generated at a GaN/sapphire interface is an important issue on the way to more reliable and mechanically stable templates for manufacturing of efficient light‐emitting diodes. One of the techniques to reduce such stresses is the formation of the patterned porous structure in a GaN film in the vicinity of the GaN/sapphire interface by GaN overgrowth. The aim of the present study is to determine the effectiveness of the described method in reducing internal stresses and to find out the preferential configuration for the patterned structure. To achieve the aim, we performed a parametrical study of stresses in the structure, which consists of a porous GaN film and a sapphire substrate, by varying geometrical parameters of the pattern. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)