Certification of the Varian VIISion Implanter for SDS(R)

Certification of the delivery system for SDS means that the tool manufacturer has demonstrated design considerations of both cylinder utilization and delivery system safety for the ultimate benefit of the end-user, as determined by the SDS vendor. Efficient utilization of SDS cylinders is an important consideration in reducing operating cost. In order to efficiently utilize the SDS, a delivery system with maximum conductance at low flow rates and pressures must be incorporated into the implanter design. Verification of this design can be accomplished by carefully instrumenting and measuring the pressure drop at various flow rates. This paper describes the characterization of the SDS gas delivery system of the new VIISion tool series and constitutes its certification for efficiently and safely utilizing the SDS gas source cylinders. In addition, precautions are taken to eliminate accidental over-pressurization of the SDS gas cylinders, such as fail-safe cross-purging between cylinder changes and proper change procedures