Domain Matching Epitaxial Growth of High-Quality ZnO Film Using a Y₂O₃ Buffer Layer on Si (111)

Abstract

High-quality ZnO epitaxial films have been grown by pulsed-laser deposition on Si (111) substrates using a nanothick high- k oxide Y 2 O 3 buffer layer. Determined by X-ray diffraction and transmission electron microscopy, the epitaxial relationship between ZnO and Y 2 O 3 follows (0001)⟨21̅1̅0⟩ ZnO ||(111)⟨101̅⟩ Y 2 O 3 . ZnO lattice aligns with the hexagonal O sublattice in Y 2 O 3 and the interfacial structure can be well described by domain matching epitaxy with 7 or 8 ZnO {112̅0} planes matching 6 or 7 {44̅0} planes of Y 2 O 3 and lead to a significant reduction of residual strain. Superior optical properties were obtained even for ZnO films as thin as 0.21 μm from photoluminescence results.