The local structural characterization of the inactive clusters in B, BF2 and BF3 implanted Si wafers using X-ray techniques

Characterization of the inactive clusters formed by high dose implantation silicon are one of the crucial topics in the semiconductor industry. Analytical techniques, which could provide quantitative information on the detailed description of the complexes that are formed at dopant concentrations above solid solubility levels, are valuable to post-implantation researchers. Previously, X-ray absorption fine-structure spectroscopy (XAFS) studies of the As and Sb implanted Si wafers revealed not only that of the chemical nature of clusters, but also the arsenic case, the ratio of the precipitated versus the substitutional form of the As in the system [1], [2]. In this study, we have used F K-edge and Ge K-edge (for the Ge pre-amorphized wafers) XAFS in order to probe the nature and of the clusters in B, BF2 and BF3 implanted Si wafers. Implants with various doses and implant energies were subjected to various annealing techniques such as laser annealing, spike annealing, solid state phase epitaxy, and flash annealing and the evolution of the spectral features of the clusters were followed upon annealing. The theoretical multiple scattering XAFS calculations were performed in order to correlate the spectral features in the XAFS data with the near-neighbor configuration around the main absorbing atom. The identification and the relative weight of the clusters after different annealing conditions will be presented in order to provide insight to the optimum annealing conditions in these systems.