| Title | Compositional and structural studies of amorphous GaN grown by ion-assisted deposition |
| Publication Type | Conference Paper |
| Year of Publication | 2002 |
| Authors | Lanke, U.D., Koo A., Ruck B.J., Lee H.K., Markwitz A., Kennedy V.J., Ariza M.J., Jones D.J., Rozière J., Bittar A., and Trodahl H.J. |
| Conference Name | Materials Research Society Symposium - Proceedings |
| Date Published | 2002 |
| Keywords | Amorphous films, Annealing, Approximation theory, Bonding, Composition, Extended x ray absorption fine structure, Film growth, Gallium nitride, Ion assisted deposition, Nuclear reaction analysis, Raman spectroscopy, Rutherford backscattering spectroscopy, Thermal effects, Transmission electron microscopy, Transparency, X ray diffraction analysis |
| Abstract | Amorphous GaN films have been deposited onto various substrates by ion-assisted deposition. The films were deposited at room temperature using nitrogen ion energies in the range 40-900 eV. Rutherford backscattering spectroscopy and nuclear reaction analysis show that the Ga:N atomic ratio is approximately one for films grown with ion energy near 500 eV; these films have the highest transparency. Films grown with ion energies below 300 eV are Ga rich, and show reduced transparency across the visible. Raman spectroscopy, x-ray diffraction, and transmission electron microscopy confirm the amorphous nature of the films. Annealing studies on a-GaN establish that the films begin to crystallise at a temperature of about 700°C. To investigate the local bonding environment of the Ga or N atoms, we have measured the extended x-ray absorption fine structure (EXAFS) of the transparent GaN films. The EXAFS results indicate that the films are dominated by heteropolar tetrahedral bonding, with a low density of homopolar bonds. |
| URL | http://www.scopus.com/inward/record.url?eid=2-s2.0-0036376612&partnerID=40&md5=1e9cab5d5cd34ebe4e3ce13033b1c708 |
