Elucidating the mechanism of transient loss of phosphorus due to interface segregation

The mechanism of the transient dose loss of phosphorus from silicon was experimentally investigated to understand mechanisms of dopant segregation at a Si O2 Si interface. Phosphorus is lost and then partially recovered during annealing after implantation. The rate of dose recovery depends on the concentration of phosphorus at the silicon surface. Dopant clustering at the interface is proposed to explain the fact that the surface concentration remains nearly constant during dose recovery. When the dose recovery rate decreases with the surface concentration declines, the trapping of dopants by individual interface defects is believed to be the major mechanism of segregation.