Measurement of Inorganic Contaminant Extraction from Fluid Handling Components by Dynamic Extraction
Donald C. Grant, CT Associates, Inc.
Travis Lemke, FSI International
Greg Duepner and Donna Wilkes, Ashland Chemical
Norm Powell, Motorola
This paper addresses extraction of inorganic contamination from fluid handling components into semiconductor process chemicals. It presents a method of dynamic extraction that measures the rate at which inorganic contaminants are extracted from components as a function of time. The method overcomes many of the shortcomings of conventional techniques. It allows prediction of the amount of contamination added to chemical in a process tool with time. Examples of its use to measure extraction from all- Teflon 0.05-?m microporous membrane filters in 49 percent HF are included. Extraction from five different types of filters was measured. Each filter was tested for 2 to 8 weeks with multiple samples taken during the course of the extraction for metal analysis. Filters of the same type had similar extraction rates and similar contaminant “finger prints.” There were large differences between filter types. The use of an inappropriate O-ring on a filter cartridge was identified. The decrease in the rate of extraction from the filters was similar to theoretical predictions.
Presented at the 41st Annual Technical Meeting, Institute of Environmental Sciences, Anaheim, CA, May 1995