Annealing behavior of Al-implantation-induced disorder in 4H-SiC

Single crystal 4H-SiC films were implanted at 150 K with 1.1 MeV Al-2(2+) and subsequently annealed at elevated 2 temperatures. In addition to the damage peak, an enhancement of the backscattering yield between the surface peak and damage peak is observed. Rutherford backscattering spectrometry results indicate that the relative Si disorder at the damage peak recovers significantly as the annealing temperature increases, and the near-surface peak disappears after annealing at 570 K. However, the residual Si disorder is more resistant to high-temperature annealing in the region of the implanted Al. The maximum concentration of Al profile measured by secondary ion mass spectroscopy is a factor of 1000 lower than the level of the residual Si disorder at the same region. Analysis of these results indicates that the excess residual Si disorder around the implanted Al projected range cannot be accounted for by just the Al interstitials; instead, it appears that implanted Al stabilizes or inhibits recovery Si disorder under the current experimental conditions. (C) 2004 Elsevier B.V. All rights reserved.