Quantitative Electron Microscopy of the InN-GaN Ternary Alloy System
Lawrence Berkeley National Laboratory (LBNL), 1 Cyclotron Road, Berkeley, CA 94720, United States
Over the last years quantitative Electron Microscopy of InxGa1-xN quantum wells and thin films contributed significantly to the development of electronic and optoelectronic devices that find numerous applications. The significant size difference between the indium (atomic radius = 0.20 nm) and gallium atoms (atomic radius = 0.18 nm), however, is known to induce substantial strain during growth of layered structures resulting into an indium distribution that can be inhomogeneous on a nanometer scale. Obviously, it is of concern that the observation of the material using high energetic electron beams can alter the as-grown structures and stimulate a redistribution of the chemically different elements. This contribution summarizes experiments that address such concerns. They range from refined sample preparation techniques to time resolved experiments that are quantitatively analyzed. It will be shown that experiments can be performed such that quantitative High Resolution Transmission Electron Microscopy, Scanning Transmission Electron Microscopy, and Electron Spectroscopy can be applied to produce a consistent set of data with no indication of beam induced damage. In contrast evidence will be given that the material exhibits spinodal decomposition. It is argued that this process influences the formation of indium rich clusters.
Presentation: invited oral at E-MRS Fall Meeting 2005, Symposium A, by Christian Kisielowski
See On-line Journal of E-MRS Fall Meeting 2005
Submitted: 2005-06-02 19:25 Revised: 2009-06-07 00:44