Influence of dislocation loops created by amorphizing implants on point defect and boron diffusion in silicon

An experiment has been pet-formed in which wafers with boron-doped, buried marker layers were implanted with 100 keV, 2 x 10(15) cm(-2) Si. This is an amorphizing implant. A second implant of B was introduced prior to any post-implant annealing such that the implanted B was completely contained within the preamorphized region. After the implants, samples were annealed at various temperatures for various times and secondary-ion mass spectroscopy was used to obtain the dopant profiles. It was found that the buried market layer exhibited normal transient-enhanced diffusion behavior. However, the B in the preamorphized region did not experience any significant amount of motion. This suggests that the solid phase regrowth of the amorphous layer did not cause a redistribution of the dopant atoms within that layer, and also the plane of dislocation loops that form at the amorphous/crystalline interface is an effective barrier against the interstitial damage diffusing upwards from the nonamorphized tail of the amorphizing Si implant. The same behavior was observed when As or P implants are used instead of the B implant. This type of behavior has been simulated using a model considering the growth of stacking faults bounded by dislocation loops. (C) 1995 American Institute of Physics.