A plasma doping process for 3D finFET source/drain extensions

A conformal doping technique is demonstrated for 3D finFET source/drain extensions using a plasma doping (PLAD) system. The arsenic dopant distribution at the top and the sidewalls of the fin was characterized by Energy Dispersive X-Ray spectroscopy (EDS) mapping, EDS line scan, and through-fin secondary ion mass spectroscopy (SIMS). The residual post-anneal damage was also evaluated by cross-section transmission electron spectroscopy (X-TEM). The effects of energy, dose and other plasma doping parameters on the sidewall dopant distribution are also studied.