Ion mass influence on transient enhanced diffusion and boron clustering in silicon: Deviation from the "+1" model

Boron in silicon doping superlattices is used to trace native point defect behavior during a 790 degrees C, 15 min anneal following a 200 keV, 1 X 10(13)/cm(2) Pb+ or 40 keV 1 x 10(13)/cm(2) Si+ implant. These nonamorphizing implants lead to transient enhanced diffusion and clustering of the boron doping spikes. The enhancement in B diffusion scales sublinearly with mass of the ion implant. Clustering of the boron occurs deeper and more extensively in the Pb+-implanted sample due to greater mass of the ion. Measurement of the number of interstitials bound by extended defects after an 800 degrees C/10 s rapid thermal anneal confirm that the Pb+ implant has "+4.5" of the implant dose bound by extended defects, compared to ''+0.6" in the Si+ implant for the same anneal. Both of these results indicate that the "+1" model is not valid for heavy mass ion implants. (C) 1998 American Institute of Physics. [S0021-8979(98)02211-7]