Fluorine diffusion: models and experiments

Fluorine has long been implanted as a co-dopant during the implant of boron into silicon in the form of BF/sub 2/, More recently its importance has increased because of its recognized ability to decrease the diffusion of the implanted boron resulting in shallower junctions, a requirement for continued transistor minimization. New experiments examining the time-dependence of fluorine diffusion in silicon have been performed, resulting in the discovery of a new fluorine diffusion behavior not described in previous research at these dose levels. We propose a physical-based model for this behavior based on these experiments that explains the anomalous motion of fluorine.