Activation and deactivation of implanted B in Si

The temporal evolution of the electrically active B fraction has been measu red experimentally on B implanted Si, and calculated using atomistic simula tion. An implant of 40 keV, 2x10(14) cm(-2) B was examined during a postimp lant anneal at 800 degrees C. The results show a low B activation (similar to 25%) for short anneal times (less than or equal to 10 s) that slowly inc reases with time (up to 40% at 1000 s), in agreement with the model propose d by Pelaz [Appl. Phys. Lett. 74, 3657 (1999)]. Based on the results, we co nclude that B clustering occurs in the presence of a high interstitial conc entration, in the very early stages of the anneal. For this reason, B clust ering is not avoided by a short or low-temperature anneal. The total dissol ution of B clusters involves thermally generated Si interstitials, and ther efore, requires long- or high-temperature anneals. (C) 1999 American Instit ute of Physics. [S0003-6951(99)01531-4].