Microstructural and compositional characteristics of GaN films grown on a ZnO-buffered Si (111) wafer

X H Luo; R M Wang; X P Zhang; H Z Zhang; D P Yu; M C Luo

doi:10.1016/j.micron.2004.01.010

Microstructural and compositional characteristics of GaN films grown on a ZnO-buffered Si (111) wafer

Micron. 2004;35(6):475-80. doi: 10.1016/j.micron.2004.01.010.

Authors

X H Luo¹, R M Wang, X P Zhang, H Z Zhang, D P Yu, M C Luo

Affiliation

¹ Electron Microscopy Laboratory and State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China.

PMID: 15120133
DOI: 10.1016/j.micron.2004.01.010

Abstract

Polycrystalline GaN thin films have been deposited epitaxially on a ZnO-buffered (111)-oriented Si substrate by molecular beam epitaxy. The microstructural and compositional characteristics of the films were studied by analytical transmission electron microscopy (TEM). A SiO(2) amorphous layer about 3.5 nm in thickness between the Si/ZnO interface has been identified by means of spatially resolved electron energy loss spectroscopy. Cross-sectional and plan-view TEM investigations reveal (GaN/ZnO/SiO(2)/Si) layers exhibiting definite a crystallographic relationship: [111](Si)//[111](ZnO)//[0001](GaN) along the epitaxy direction. GaN films are polycrystalline with nanoscale grains ( approximately 100 nm in size) grown along [0001] direction with about 20 degrees between the (1l00) planes of adjacent grains. A three-dimensional growth mode for the buffer layer and the film is proposed to explain the formation of the as-grown polycrystalline GaN films and the functionality of the buffer layer.