Depth-resolved luminescence imaging of epitaxial lateral overgrown GaN using ionoluminescence

Abstract

In this article, we utilize energetic mega-electron-volt (MeV) H + to excite light emission from epitaxial lateral overgrown GaN. Due to the high-penetration depth of MeV ions, this technique allows us to probe several microns below the surface, down to the interface region. Spatially and depth-resolved yellow luminescence imaging is carried out using a focused H + beam with energies of 0.5, 0.75 and 1MeV. Results show an increase of the yellow luminescence with depth in the window regions with respect to the wing regions. Since the threading dislocations propagate to the surface, this suggests that the yellow luminescence is due to the point defects rather than threading dislocations. © 2004 Elsevier B.V. All rights reserved.