In-plane GaN/AlGaN heterostructure fabricated by selective mass transport planar technology

We found that the mass transport of GaN occurs at around 1100 °C under NH3-containing atmosphere if a trench is artificially formed, while that of Al0.1Ga0.9N does not. This different behavior of these two materials was utilized in the fabrication of an in-plane periodical GaN/AlGaN structure. Periodical trenches were formed on the surface of a GaN/Al0.1Ga0.9N heterostructure, the depth of which reached the bottom of the Al0.1Ga0.9N layer. After annealing for 60 min, all the GaN on the terrace surface was selectively transported into the trenches, and then the flat surface of the underlying Al0.1Ga0.9N was exposed. Thus, an in-plane periodical GaN/Al0.1Ga0.9N grating was formed. This grating was characterized by micro-photoluminescence mapping.