Phosphorus redistribution caused by electrical deactivation of phosphorus at low temperatures

Electrical deactivation of phosphorus was investigated using silicon-on-insulator (SOI) wafers with uniform phosphorus profiles prepared by ion implantation and annealing at high temperatures. Evident depletion of phosphorus was observed in the bulk region of the active silicon layer when electrical deactivation of phosphorus occurred at low temperatures. Such phenomenon was due to uphill diffusion of phosphorus toward the surface. Retrograde profiles of excess interstitials generated during deactivation were proposed to explain the redistribution of phosphorus.