Inline VPD-TXRF for Contamination Control: Reality or Myth? Experience in a 300mm R&D MirrorBit Flash Memory Fab

Recent advances in TXRF hardware and software and highly successful integration of automated VPD modules to TXRF have made inline vapor phase decomposition-total reflection X-ray fluorescence (VPD-TXRF) a reality. In this paper we describe the use of and application of a fully integrated VPD-TXRF system capable of analyzing 200 mm and 300 mm diameter silicon wafers during the critical conversion period of an R&D MirrorBit Flash Fabrication facility to 300 mm. Rapid deployment of such an automated system during the conversion period has enabled us to 1) efficiently bench mark and qualify newly installed processing tools 2) assess the validity of existing protocols and procedures 3) respond very quickly to incidences where protocols have been breached and 4) identify process tools that heavily contaminate the backside of wafers.