Comparison of Bacteria Enumeration Between A Filter Culture Method And A Laser Scanning Cytometry Method

摘要

Semiconductor manufacturers strive to have the cleanest process water available for manufacturing their products. As line widths continue to shrink, concern about contamination on the wafer grows. One area of continuous improvement is reduction of the bacteria and bio-burden in the ultra-pure water (UPW) that touches the wafer surface. Methods that improve our ability to detect bacteria by culture frequently require longer times for incubation. Technology that was presented at the SPWCC in 1998 by researchers for Kurita Water Industries in their paper Analysis of Bacteria in Ultrapure Water Systems using Fluorescent Probe and Culture Method~2 offered an alternative method for rapid and improved sensitivity for enumerating bacteria. Texas Instruments (TI) has invested in comparing the two methods. This paper compares our 96 hour incubation standard method to the solid phase laser scanning cytometry method. The laser scanning cytometry instrument and reagents used for our tests are marketed by AES Chemunex. The sensitivity of the Chemunex ChemScan C far surpasses that of our established culture methods.