Energy dependence of transient-enhanced-diffusion in low energy high dose arsenic implants in silicon

Si wafers were implanted with As at energies ranging from 10-50 keV to a constant dose of 5e15/cm/sup 2/ and annealed at 700C for various times to study transient-enhanced-diffusion of arsenic and its correlation to the defect microstructure. The results showed that the diffusion enhancement was maximum after a 30 keV implant and anneal. The defect microstructure consisted of only end of range damage in the 10 and 20 keV specimens while the 30, 40 and 50 keV implanted/annealed specimens contained both end of range and projected range defects. An explanation for these observations is suggested, after taking into account a combination of factors that include arsenic precipitation, arsenic clustering and point defect annihilation at the surface.