Heavy metal contamination in ion implantation

摘要

Reduction of metallic contamination during ion implantation is becoming increasingly critical for device performance. Modern implanters are being developed with novel beamline coating materials and optics to keep sputtered contamination to a minimum. However chemical processes occur in the implanter which lead to contaminants being deposited onto the surface of beam optical elements from where they may be transferred to the wafer. We have found that these effects are time and species dependent and are new revealed because of the dramatically reduced contamination levels we have achieved and the improved analysis process control that we employ.