Fig. 2From: Infrared Reflectance Analysis of Epitaxial n-Type Doped GaN Layers Grown on SapphireSEM image of cross-section of the investigated n+/n0/n+-GaN structure. The irregular pattern of vertical lines was formed during cleaving (i.e., before photo-etching) and is characteristic for the non-polished cleavages of Al2O3/GaN hetero-structures. Rough pyramidal layer (pinholes) at the sapphire/GaN template indicated by the arrow was revealed by photo-etchingBack to article page