The behavior of Fe atoms during simulated device fabrication was studied. The results of electron microscopic and deep-level transient spectroscopic analyses indicated that Fe, at concentrations below the solubility limit, precipitated at bulk stacking faults which contained an oxide precipitate. On the basis of the defect morphology, and the eutectoid temperature of the -FeSi2 phase, it was suggested that Fe precipitation occurred during cooling after high-temperature treatment. The results showed that Fe could react with O atoms in the oxide precipitate via a phase transformation which in turn caused a change in the precipitate morphology. It was suggested here that Fe precipitation at bulk defects was fundamentally different to that of Ni or Cu, where precipitation occurred along the Frank partial dislocations of the bulk stacking fault or at punched-out dislocation loops which originated at the oxide precipitate interface.

W.Wijaranakula: Journal of Applied Physics, 1996, 79[8], 4450-2