Epitaxial growth of group III nitrides on silicon substrates via a reflective lattice-matched zirconium diboride buffer layer

Abstract

Growth of metallic and reflecting ZrB2 films is conducted on Si(111) substrates at 900 °C using a single-source unimolecular precursor Zr(BH4)4 in a molecular beam epitaxy chamber. Epitaxial growth of ZrB2(0001) is accomplished despite the very large lattice mismatch between ZrB2 and Si(111). High-resolution cross-sectional transmission electron microscopy images of the sharp ZrB2/Si(111) interface show a heteroepitaxial relationship involving a “magic mismatch” of coincidence lattices. The GaN films grown on the ZrB2/Si(111) template is virtually homoepitaxy because of the very small lattice mismatch, 0.6%, between the in-plane lattice parameters of ZrB2(0001) and GaN(0001).