Silicon di-interstitial in ion-implanted silicon

A new Si di-interstitial model is derived from the Si-P6 electron paramagnetic resonance spectrum observed in neutron-, proton-, or ion-implanted silicon. Two Si interstitials lie in the {100} plane at a position considerably off from two tetrahedral interstitial sites nearby, sharing one Si lattice atom. The di-interstitial disappears at 170 °C annealing and can form the 〈110〉 interstitial chains which are considered to be a “building block” of the {311} extended defects frequently observed in ion-implanted Si.