Gettering of copper to hydrogen-induced cavities in multicrystalline silicon

The gettering properties of hydrogen-induced cavities have been examined for Cu impurity atoms inherent in multicrystalline Si. Initial areal densities of Cu atoms in the multicrystalline samples were in the range of (3-5) × 1013 cm-2, below the level that would provide a complete monolayer coverage of the internal surfaces of the cavities. Samples were first implanted with hydrogen and then annealed at 750 or 850 °C for 1 h to form cavities and induce subsequent gettering. Neutron activation analysis with chemical etching of the samples indicated that more than 90% of Cu atoms could be removed from the entire wafer by cavity gettering for both of the annealing temperatures.