“Condensation” of impurities in semiconductors (Si + Li)

The kinetics of Li precipitation in Si at the maximum doping level was investigated. The time dependence of the electron concentration and Hall mobility in the course of annealing at 300 and 350°K turned out to differ strongly from the ordinary kinetics of solid solution precipitation. The explanation proposed for the features observed assumes the appearance of a spatially inhomogenous Li-ion distribution in the crystal and the formation of electron-ion drops with a density of ～ 2?3 × 10²⁰ cm^?3.