Diffusion Modeling of the Redistribution of Ion Implanted Impurities

Abstract

ABSTRACTTransient enhanced diffusion during rapid thermal processing has been reported for most of the common dopants employed for silicon device fabrication. For arsenic a large amount of the available data is fit by a computational model based on accepted diffusion mechanisms. Ion implanted boron on the other hand exhibits anomalous tails and transient motiou. A time dependence of this displacement is demonstrated at lower temperatures. High temperature rapid anneals are shown to reduce some of the anomalous motion observed for low temperature furnace anneals. A model is described that links the electrical activation with the diffusion and describes both the transient diffusion of rapid thermal processing and the large anomalous diffusion reported many years ago for furnace anneals.