Observation of iron impurity diffusion in silicon under bending stress by Mössbauer spectroscopy

Abstract

External bending stress was applied to a 57Fe-doped n-type silicon wafer, and transmission Mossbauer spectra were measured at room temperature in order to observe directly stress induced diffusion of 57Fe atoms in the silicon matrix. As the stress is increased up to 23 MPa, the resonance area of the substitutional Fes component is found to decrease by more than 30%. In addition, a line broadening can be clearly seen in the interstitial Fe $_{\rm i}^{0}$ component, corresponding to a jump frequency of 106 s − 1. This diffusion process is interpreted to be due to the fast jumps between interstitial sites, following a formation jump of interstitial Fe $_{\rm i}^{0}$ from substitutional Fes.