Investigations of impurity gettering in multicrystalline silicon

Abstract

The processes of gettering the recombination-active impurities in multicrystalline silicon were investigated using methods of mass spectrometry of neutral atoms with the depth profile analysis and spectroscopy of a surface photovoltage (permitting to determine the diffusion length of nonequilibrium charge carriers). Getters formed by a silicon layer with a developed internal surface, and also combined getter (the mentioned layer covered with a thin film of aluminum) were used. It was shown that the efficiency of gettering depends on annealing temperature and character of Al depth distribution that, in turn, depends on the regimes of structurally modified silicon layer formation. The models of gettering that enabled us to explain obtained results are considered.