Determination of dislocation loop size and density in ion implanted and annealed silicon by simulation of triple crystal X-ray rocking curves

Interstitial perfect dislocation loops are generated in silicon by high dose silicon ion implantation and furnace annealing in the range 700 to 1000 °C. Triple crystal diffraction curves are obtained from each sample with the parallel (n,–n, n) configuration by measuring the internsity of the main peak as a function of the angular position of the specimen. This procedure allows to make the contribution of Huang diffuse scattering given by the loops to the dynamically diffracted intensity negligible and the sensitivity to lattice distortion higher than in double crystal diffraction case. The truple crystal diffraction curves are simlutatd by computer through application of the dynamical theory of diffraction frojm imperfect crystals. The depth profiles of lattice strain and static atomic disorder are determined. A simple model is used relating these two parameters to the mean radius and surface concentration of the loops. Tthe temperature evolution of size and density of these defects is therefore obtained and compared with the one directly derved by transmission electron microscopy images. The good agreement shown by this comparison ndicates the validity of the model applied and the effectiveness of triple crystal diffraction in the analysis of defects producing Huang scattering.