抄録
For finding the effective gettering center of cupper (Cu) impurity atom in silicon crystal, an interaction between interstitial Cu atom and substitutional dopant or carben (C) atom was studied by first principle calculations. The interaction energies of Cu and boron (B), antimony (Sb), arsenic (As), phosphorus (P) or C were estimated. It was found that only B can be an effective gettering center for Cu. This result indicates that heavily B doped P/P+epitaxial wafers will show a sufficient gettering efficiency for Cu contamination. The other calculations showed that vacancy (Vcy) -Sb, Vcy-As or Vcy-P complexes can be formed. In order to design the gettering center for Cu in nln+ epitaxial wafers, the interaction between these complexes and Cu was investigated. It was found that these complexes can be an effective gettering center for Cu. This result proposes a new Cu gettering technique in n/n+ epitaxial wafers with the formation of Vcy-Sb, Vcy-As or Vcy-P complexes.
