GaN nanorods and LED structures grown on patterned Si and AlN/Si substrates by selective area growth

Abstract

AbstractGaN nanorods (NRs) show promising applications in high‐efficiency light emitting diodes, monolithic white light emission and optical interconnection due to their superior properties. In this work, we performed GaN nanostructures growth by pre‐patterning the Si and AlN/Si substrates. The pattern was transferred to Si and AlN/Si substrates by photolithography and inductively‐coupled plasma etching. GaN NRs were grown on these templates by metal‐organic vapour phase epitaxy (MOVPE). GaN grown on Si pillar templates show a truncated pyramidal structure. Transmission electron microscopy measurements demonstrated clearly that the threading dislocations bend to the side facets of the GaN nanostructures and terminate. GaN growth can also be observed on the sidewalls and bottom surface between the Si pillars. A simple phenomenological model is proposed to explain the GaN nanostructure growth on Si pillar templates. Based on this model, we developed another growth method, by which we grow GaN rod structures on pre‐patterned AlN/Si templates. By in‐situ nitridation and decreasing of the V/III ratio, we found that GaN rods only grew on the patterned AlN/Si dots with an aspect ratio of about 1.5 ‐ 2. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)