The Dominant Iron Gettering Mechanism in P/P+ Silicon Wafers

Fe gettering mechanisms in p/p+ epitaxial Si were investigated under controlled contamination and annealing cycles. The dominant Fe gettering mechanism is the Fermi level controlled coulomb attraction between Fe+ and B- in the p+ substrate of the p/p+ wafers. Oxygen precipitates do not appear to controbute when using normal cooling rates following heat treatments. The epi-substrate interfacial strain plays no role in Fe gettering.