Using boron cluster ion implantation to fabricate ultra-shallow junctions

B₁₈H_x⁺ and B ion implantation have been used to fabricate the SDE of pMOSFETs with gate lengths of ∼60 nm. Ultra high resolution mass spectra of natural abundance B₁₈H₂₂ and mass 11 isotopically enriched B₁₈H₂₂ have been used to achieve deconvolution of the binominal distribution from ion states present in the cluster ion beam. The cluster source has been specifically designed to maintain the integrity of the cluster during the ionization process. The results of B₁₈H_x⁺ and B are compared from the viewpoint of transistor performance. The implants were performed at equivalent process energies and doses. It has been shown that B implantation greatly increases the throughput of low energy boron implants while delivering uncompromised device performance.