Method for reducing cross-contamination in ion implantation

摘要

This ion implantation method reduces the observed levels of cross-contamination and reduces the level of variations in surface conductivity related to the provision of multiple ion implantations into a semiconductor wafer. Reduced levels of cross-contamination are obtained by purging the implantation chamber and then evacuating the implantation chamber before beginning an implantation process. This purge and evacuation cycle is believed to be particularly effective in reducing cross-contamination when two implantations are made consecutively into a wafer without removing the wafer from the implantation chamber or when successive wafers are transported into the ion implantation chamber and implantations are made into each successive wafer.