GETTERING OF PLATINUM AND SILVER TO CAVITIES FORMED BY HYDROGEN IMPLANTATION IN SILICON

The gettering of Pt and Ag to hydrogen-induced cavities was studied us ing Rutherford backscattering (RES) and secondary ion mass spectrometr y (SIMS) for metal doses ranging from 1 x 10(13) to 1 x 10(15) cm(-2). Almost 100% of the introduced metals were relocated to the cavity ban d for doses lower than 1 x 10(14) cm(-2) and 3 x 10(14) cm(-2) for Pt and Ag, respectively. However, the extent of gettering was observed to be dose dependent. At a higher metal-implant dose of 1 x 10(15) cm(-2 ), the extent of gettering decreased to 6% for Pt and 50% for Ag. We s uggest that silicide phase formation, favoured in the case of high dos e Pt, is the main cause of the differences observed between Pt and Ag. Our results indicate that the extent of gettering is influenced stron gly by the state of the metal within the implanted layer during anneal ing.