Pilot-Scale Application of on-Line Monitoring System for Ultrapure Water

The on-line monitoring system for ultrapure water (UPW) systems was investigated. For the quality control of production water and the screening of defective water during the production of semiconductors and displays, as well as the operation of plant turbines, ultrapure water is managed through on-line and off-line monitoring of its conductivity and resistivity as well as its silicate, heavy metal, total organic carbon (TOC) and particle content. The American Society for Testing and Materials (ASTM) has developed and proposed seven types of electronics-grade water for the production of electronics and semiconductors. Type E-1.3 is classified as microelectronic water to be used in the production of devices having line widths between 0.065 and 0.032μm. This type is a water of ultimate practical purity produced in large volumes, and is intended for the most critical microelectronic uses. ASTM Type E-1.3 is also identical to the SEMI (Semiconductor Equipment and Materials International) Guide for Ultrapure Water Used in Semiconductor Processing (F063), 2010 version. The monitoring system of this study was operated in a pilot-scale ultrapure water plant having facilities with a production capacity of 50 m3/d. The results of system operations yielded water having an average TOC of 0.002 μg/L (Min. 0.001 μg/L, Max. 0.005 μg/L), an average particle content of 0.4 ea/L (> 0.05 μm, Min. 0.3 ea/L, Max. 0.8 ea/L), and a resistivity of 18.15 MΩ•cm. The results above indicated that the water quality standards provided in the Type E-1.2 specifications proposed by ASTM were satisfied.