Application of isotopically enriched germanium tetrafluoride for contaminant reduction and ion source lifetime benefits

Wafer contamination is a critical factor in today´s semiconductor fabs. This paper discusses Philips Semiconductor´s efforts to reduce iron contamination, as observed on Axcelis GSD´s implanting boron and germanium at the New York based fab. While implementing the process to reduce the iron contamination, it was discovered that the ion source lifetime had been significantly increased by the use of isotopically enriched germanium tetrafluoride. Information and data will be presented to confirm the significant increased lifetime and the reduction of iron contamination.