overview

　　The revolutionary Sievers* UPW Boron Analyzer is the first on-line instrument to enable continuous, unattended online monitoring of part-per-trillion levels of boron in deionized (DI) ultrapure water (UPW) applications. Sievers developed this patented UPW Boron Analyzer in cooperation with semiconductor manufacturers. As the dimensions of the semiconductor components continue to shrink, colloidal silica is becoming increasingly critical to remove from semiconductor UPW. The most valuable use of this analyzer is to minimize and control the leakage of colloidal and ionic silica from ion removal processes like mixed-bed ion exchange and electronic deionization (EDI) to improve chip yield. Additionally, it is used to control the deionization process to meet the ITRS 0.050 ppb boron limit in semiconductor UPW. It is designed specifically to meet the needs of facility managers, DI water engineers, and fab process engineers.

　　On-line Performance

　　Possessing the part-per-trillion sensitivity of ICP/MS1 (Figures 1 and 2), the Boron Analyzer ensures the effective control of silica and boron, compliance with primary and polish loop boron specifications, and the minimization of colloidal and ionic silica. At up to ten analyses per hour, facility managers can protect against upset conditions that would go undetected with ICP/MS or other laboratory analysis methods.

　　Process Optimization

　　Numerous published articles1-5 identify boron as the best indication of mixed-bed ion exchange resin exhaustion for the effective removal of both silica and boron. At the point of measurable increase in silica concentration, boron breakthrough has typically been underway for a prolonged period of time, causing significant exposure to processes that may be sensitive to boron. The Boron Analyzer was specifically designed to better predict mixed-bed exhaustion, allowing the optimized control of both silica and boron levels in the final polish UPW system. The Analyzer is successfully being used to increase the lifetime of the polish loop mixed-bed ion exchange to save operational expenses.4