Nanoheteroepitaxial growth of GaN on Si by organometallic vapor phase epitaxy

Nanoheteroepitaxy has recently been proposed as a technique for significantly extending the thickness of pseudomorphic growth in mismatched heterostructures. This letter reports the experimental application of nanoheteroepitaxy for the growth of GaN on patterned 〈111〉 oriented silicon-on-insulator substrates by organometallic vapor phase epitaxy. Transmission electron microscopy reveals that the defect concentration decays rapidly away from the heterointerface as predicted by nanoheteroepitaxy theory. The melting point of the nanoscale islands is found to be significantly reduced, enhancing substrate compliance and further reducing the strain energy in the GaN epitaxial layer.