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.