Effect of arsenic doping on {311} defect dissolution in silicon

Si+ ions were implanted into silicon wafers with background concentrations of arsenic ranging from 1 x 10(17) to 3 x 10(19) cm(-3) to study the intera ction between arsenic atoms and excess self-interstitials. Samples were the n annealed at 750 degrees C for a range of times between 15 and 60 min to n ucleate and dissolve {311} defects. The concentration of trapped interstiti als in these defects was measured using quantitative plan-view transmission electron microscopy. It is shown that, as the arsenic concentration increa ses, there is a reduction in the number and size of the {311} defects. This decrease in the {311} defect density with increasing arsenic well concentr ation is believed to be the result of interstitial trapping by the arsenic. Upon annealing, the trapped interstitial concentration in the {311} defect s decreases as the defects dissolve. The time constant for the dissolution was calculated to be 33 +/- 5 min at 750 degrees C, and was independent of background concentration. This suggests that the arsenic traps some of the interstitials, and these traps are sufficiently stable that they do not aff ect the subsequent {311} dissolution at 750 degrees C. (C) 1999 American In stitute of Physics. [S0003-6951(99)04628-8].