Gettering of copper to hydrogen-induced cavities in silicon

Hydrogen implantation and subsequent thermal annealing is found to result in a well-defined band of cavities in Si. This band is an extremely efficient gettering layer for Cu which is also introduced into the near surface of Si by ion implantation. Profiling of implanted Cu indicates that ∼95% of an initial 3×10¹⁵cm^-2 Cu implant is redistributed following annealing at a temperature of 780°C from a near-surface damaged layer to a narrow band of cavities of width ∼1000 Å at a depth of ∼1 μm. Furthermore, the Si between the surface and the cavity band is essentially defect-free and that some cavities contain the bulk Cu₃Si phase.