Implementation of molecular ion implant technology for PMOS extension implants and their compatibility with DRAM process flows

Molecular B and molecular C have been implanted in PMOS devices at the source drain extension (SDE) level. Different implant sequences have been compared in which Bi₈H₂₂ and C₁₆H₁₀ have been combined with pre-amorphization and co-implants. Bi₈H₂₂ shows very good Vt roll-off behaviour and low junction leakage. Molecular C stabilizes junctions in post-processing DRAM annealing. Both molecular species show the potential to combine the beneficial effects of a pre-amorphization implant followed by a C and B implant in the formation of ultra-shallow junctions.