Redistribution of P atoms in oxidized P-implanted silicon during annealing

Phosphorus ions were implanted into silicon at energies of 20similar to200 keV and then a region ranging from the surface to about 0.26 nm was oxidized in wet-oxygen atmosphere at 1000degreesC for 90 min. Two groups, samples (capped samples) for which the SiO2 was not removed, and samples (removed samples) for which the SiO2 was removed, were prepared from the oxidized samples. Subsequently, the samples were annealed in inert gas at 1000 degreesC for 30similar to180 min. The annealed capped samples prepared from the 20 keV ion-implanted silicon had approximately the same P atom distribution profiles as the as-oxidized sample regardless of annealing time: the implanted P atoms had not diffused into silicon during the annealing. The annealed removed samples had P atom distribution profiles approximated by a solution of the diffusion equation with constant-total-dopant. When the samples prepared from the 200 keV ion-implanted silicon were annealed, the distribution profiles of carriers were approximated the same regardless of whether or not the SiO2 film was removed from the sample. (C) 2004 Kluwer Academic Publishers.