Implant dosimetry results for plasma doping

A system for accurate and repeatable implant dose measurement for plasma doping architectures must circumvent a number of possible pitfalls. Such a system must accurately count ions crossing the pulsed plasma sheath to the wafer surface, while that surface is typically at high potential and immersed in the ambient plasma environment of the wafer. The effects of secondary electrons and the capacitive displacement current must be suppressed and the measurement itself must not alter the plasma or be affected by the high potential of the wafer bias. Traditional Faraday systems do not address these requirements. A new dose measurement system has been developed to meet the needs of pulsed plasma doping and the performance of that system for dose accuracy, repeatability, and uniformity is described