The use of electron back-scattering diffraction mapping and electron channeling contrast imaging—in the scanning electron microscope—to study tilt, atomic steps and dislocations in epitaxial GaN thin films was described. Results were presented from a series of GaN thin films of increasing thickness, and from a just-coalesced epitaxial laterally overgrown GaN thin film. From the results, it was deduced that electron back-scattering diffraction could be used to measure orientation changes of the order of 0.02°, in GaN thin films. As the electron back-scattering diffraction had a spatial resolution of about 20nm, it was concluded that this made it a powerful technique with which to map surface tilt quantitatively. It was also demonstrated that electron channeling contrast images could be used to image tilt, atomic steps and threading dislocations in GaN thin films.

Electron Backscatter Diffraction and Electron Channeling Contrast Imaging of Tilt and Dislocations in Nitride Thin Films. C.Trager-Cowan, F.Sweeney, P.W.Trimby, A.P.Day, A.Gholinia, N.H.Schmidt, P.J.Parbrook, A.J.Wilkinson, I.M.Watson: Physical Review B, 2007, 75[8], 085301 (8pp)