Low-temperature redistribution of As in Si during Pd2Si formation

We have investigated the change in depth compositional profiles of implanted As in Si due to Pd2Si formation by using anodic oxidation and neutron activation analysis. We found that a high concentration (∼1×1021/cm3) of implanted As was snowplowed by the moving silicide-Si interface into the substrate Si during Pd2Si formation at 250 °C. In other words, we have found a very low temperature process of doping As into Si. The amount of snowplowed As was found to be greater in samples which were preannealed at 900 °C—30 min before silicide formation than those without the preannealing.