GaN nano-pendeo-epitaxy on Si(111) substrates

Nano-pendeo-epitaxial GaN films have been grown by metalorganic vapour phase epitaxy on nanocolumns fabricated on thin GaN-on-Si(111) templates. Optical and structural performances of the films are improved, crack densities are reduced, and self-separation of GaN films from the substrates at the nanocolumns has been realized. The success of the nano-pendeo-epitaxy of GaN films is attributed to the following three techniques developed in this study: (1) the growth of high quality ultrathin GaN/AlN templates on on Si(111) substrates, (2) the fabrication of uniform nanocolumns across the 2-inch wafer surface, and (3) the in situ conversion of the exposed silicon surfaces of the fabricated nanocolumns to silicon nitride.