Epitaxial single-crystal GaN films on sapphire were implanted 60? off the surface normal with 1 MeV Au2?or 3 MeV Au3? over a fluence range from 0.88 to 86.2 ions/nm2 at 180 and 300 K. The implantation damage was studied in-situ using 2 MeV He? Rutherford backscattering spectrometry in channeling geometry (RBS/C). The disordering rate in the near-surface region is faster than at the damage peak. In all cases, results show an intermediate stage of Ga disorder saturation at the damage peak. Migration of Au implants in GaN is observed during ion implantation at 300 K. As a result of thermal annealing at 870 K for 20 min, some Au implants in GaN diffuse into the amorphized surface region, while the remaining Au atoms distribute around the mean ion-projected-range. These results suggest a high mobility of both Ga defects and Au implants in GaN. Deeper damage implantation by 3 MeV Au3? indicates that GaN cannot be completely amorphized up to the highest ion fluence (86.2 ions/nm2) applied at 300 K.
Revised: May 20, 2004 |
Published: April 25, 2001
Citation
Jiang W., W.J. Weber, S. Thevuthasan, and V. Shutthanandan. 2001.Properties of Gallium Disorder and Gold Implants in GaN. In Ion Beam Synthesis and Processing of Advanced Materials, Materials Research Society Symposium Proceedings, edited by DB Poker, SC Moss, K-H Heinig, 647, O5.9(1-6). Warrendale, Pennsylvania:Materials Research Society.PNNL-SA-33950.