The Influence of Cavities and Point Defects on Cu Gettering and B'Diffusion in Si

Abstract

ABSTRACTCavities, formed in Si by hydrogen implantation and subsequent annealing, can provide ideal gettering sites for metal impurities. In this study, we have observed large differences in the accumulation of Cu at cavities depending on whether Cu was introduced into Si during cavity formation or into wafers with pre-formed cavities. The observed behaviour is consistent with a high flux of Si interstitials emitted during cavity formation which induce the dissolution of Cu3Si and the enhanced transport of Cu to cavities. In further studies, boron implantation was carried out into wafers containing pre-formed cavities and transient enhanced diffusion (TED) of boron was suppressed duringsubsequent annealing.