Implantation and transient boron diffusion: the role of the silicon self-interstitial

Abstract

The phenomena associated with the transient diffusion of implanted B in Si are reviewed. The Si self-interstitial flux, which causes the B interstitialcy diffusion, has been directly observed by the use of B diffusion marker layers fabricated by low-temperature crystal growth. Low-energy and low-dose Si implants in surface layers permit the experimental separation of the source and flux of interstitials. The clustering of B is directly correlated with the supersaturation of injected Si interstitials. The diffusivity of the Si interstitial is dominated by the presence of trapping sites. Implantation produces rod-like defects which consist of interstitial precipitates on {311} planes as a single monolayer of hexagonal Si. The number of Si interstitials evaporating from the {311} defect is sufficient to explain the whole of the transient diffusion.