Source/drain profile engineering with plasma implantation

Shallow junction profiles are controlled by the variable implant profile, implant damage profile and annealing cycle. For plasma immersion ion implantation (PIII) systems, the dopant and damage profiles vary with plasma source conditions and implanter waveforms. These can lead to different implant profiles for the same dose and energy, and different junction profiles after annealing. In the low energy regime, the as-implanted profiles resemble those from conventional implanters. In the Berkeley PIII system, a 55 nm p/sup +/ junction is formed by 1 kV BF/sub 3/ PIII implantation and a two-step rapid thermal annealing cycle.