Distribution and Chemical State of Cu-rich Clusters in Silicon: Preprint

the chemical state and distribution of Cu-rich clusters were determined in four different silicon-based materials with varying contamination pathways and degrees of oxygen concentration, including as-grown multicrystalline silicon. In all four samples, Cu3Si was the only chemical state observed. Cu3Si clusters were observed at structural defects within all four materials; XBIC measurementsrevealed that the presence of Cu3Si corresponds to increased recombination activity. Oxidized Cu compounds are not likely to form in silicon. The +1 eV edge shift in the ?-XAS absorption spectrum of Cu3Si relative to Cu metal is believed to be an indication of a degree of covalent bonding between Cu atoms and their silicon neighbors.