Formation of S/D-extension using boron gas cluster ion beam doping for sub-50-nm PMOSFET

Boron doping using gas cluster ion beam (GCIB) is implemented for formation of source/drain-extension (SDE) of pMOSFETs with sub-50-nm gate length. As compared with low energy ion implantation, GCIB is confirmed to produce steep profile of ∼2.5 nm/decade without tail distribution. By simple replacement of low energy boron implantation with GCIB doping, about 20-nm improvement in short-channel effect and almost the same current drivability are obtained for pMOSFETs. Considering that conventional spike RTA and no offset space were used in the fabrication process, GCIB doping is considered to be promising technology for 45-nm node and beyond.