Sm. Myers et al., METAL GETTERING BY BORON-SILICIDE PRECIPITATES IN BORON-IMPLANTED SILICON, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 127, 1997, pp. 291-296
We show that Fe, Co, Cu and Au impurities in Si are strongly gettered
to boron-silicide precipitates formed by supersaturation boron implant
ation and annealing. Effective binding free energies relative to inter
stitial solution are extracted and range from about 1.2 to 2.2 eV. The
B-Si precipitates formed at temperatures less than or equal to 1100 d
egrees C lack long range structural order but are similar to crystalli
ne B3Si in composition and B chemical potential, Evidence indicates th
at the metal atoms go into solution in the B-Si phase, and this is int
erpreted in terms of the novel bonding and structural characteristics
of B-rich icosahedral compounds.