Advances in molecular implant technology

Molecular implant (aka Cluster Implant) has been established as an alternative for boron and carbon implants in advanced technology applications. The unique features of molecular implant (especially self-amorphization and low EOR damage) enable the formation of aggressively shallow USJ with very high quality. Recent results using 300eV monomer equivalent implant energies will show junctions of 10nm, with low resistance. Experiments include the use of spike, millisecond and microsecond anneals, all with excellent results. In addition, the influence of carbon co-implants are shown to be significant even for these advanced implant and anneal processes. The variety of available carbon molecules will be discussed, focusing on the Si:C stress application. The requirement for stressor layer thickness drives the choice of carbon molecule and stressor layers up to 60nm in thickness will be discussed. In addition, the interaction between the carbon and dopant atoms will be shown to create a process window of moderate concentrations where good dopant junctions and effective stress layers can be formed.