Room temperature epitaxial growth of m -plane GaN on lattice-matched ZnO substrates

Abstract

The authors have grown high-quality m -plane GaN (1 1- 00) films on ZnO (1 1- 00) substrates using pulsed laser deposition. They have found that annealing in a box made of ceramic ZnO improves the surface morphology of m -plane ZnO substrates and have succeeded in the layer-by-layer growth of m -plane GaN on the annealed ZnO substrates even at room temperature (RT). X-ray diffraction reveals that high crystalline quality m -plane GaN grows on the RT buffer layer at 700°C. The 300-nm -thick m -plane GaN film grown on the ZnO substrate contains the residual strains because the lattice mismatches between them are quite small. The relationship of in-plane and out-of-plane strains is consistent with the calculation using the elastic constants. © 2007 American Institute of Physics.