New insight on the interaction and diffusion properties of ion beam injected self-interstitials in crystalline silicon

The diffusion of ion beam injected self-interstitials (1) and their interaction with impurities in crystalline Si has been investigated and modeled. In particular, the I-substitutional carbon (C) interactions have been studied, using a molecular-beam-epitaxy grown Si1-yCy layer interposed between the shallow I-source and a deeper B-spike (marker for I-concentration). Substitutional C atoms are shown to trap I's, to be removed from their substitutional sites, and to form stable precipitates into the C-rich region. The I-trapping mechanism was quantitatively studied by a simulation code. The reactions causing trapping and deactivation are described. In addition, the boron markers approach was extended to the two dimensional (2D) diffusion. High resolution scanning capacitance microscopy was used for quantitative measurements of the 2D boron transient enhanced diffusion induced on a boron delta array by the I's ion beam injected through a sub-micron dimension oxide mask. A simulation code was developed to describe the 2D I-diffusion and a quantitative description of the 2D I-evolution has been obtained. Source size effects have been found and modeled.