Mechanisms for P diffusion gettering (PDG) for iron were supplemented by possible formation of iron-phosphorus complexes in heavy P-doped region. Existence of such complexes was recently reported based on the results of electron-spin resonance investigations. deep-level transient spectroscopy measurements suggested a high probability for the formation of iron-phosphorus complexes in n-type Si in the presence of vacancies and/or vacancy-phosphorus pairs. On the other hand, recent theoretical calculations predict formation of negatively charged vacancy-phosphorus pairs in the heavily P-doped region of Si during PDG. These facts indicated on possibility to explain the high efficiency of the PDG process for iron by assuming formation of iron-phosphorus complexes in the heavy P-doped region of silicon. Possible advantages of application of H or N assisted PDG were considered.

Involvement of Iron-Phosphorus Complexes in Iron Gettering for n-Type Silicon. T.Mchedlidze, M.Kittler: Physica Status Solidi A, 2006, 203[4], 786-91