The redistribution of As during high-temperature annealing was investigated as a function of the (100) substrate temperature (-120, 25 or 300C) during 2.5keV implantation to a dose of 1.5 x 1015/cm2. Each implant produced a damaged near-surface region whose extent varied with implantation temperature. Samples which were implanted at each temperature were annealed (550, 925 or 975C, 15s) in a N ambient which contained a few percent of O. Changes in the implantation damage and dopant distributions before and after annealing were investigated by using medium-energy ion scattering and secondary ion mass spectrometry. A transient enhanced diffusion of the dopant was observed for all implantation temperatures after 925C annealing. The 25C-implanted specimens exhibited the deepest diffusion. When annealing at between 925 and 975C, the As diffusion rate in the 300C-implanted specimens exceeded that in 25C-implanted specimens. It was noted that -120C-implanted specimens exhibited less As transient enhanced diffusion than did higher-temperature implanted specimens following annealing at 975C. The results indicated that the diffusion was affected by the nature of the post-implantation damage and the high As concentrations.

The Dependence of Arsenic Transient Enhanced Diffusion on the Silicon Substrate Temperature during Ultra-Low Energy Implantation S.Whelan, J.A.Van den Berg, S.Zhang, D.G.Armour, R.D.Goldberg: Applied Physics Letters, 2000, 76[5], 571-3