Qualification of chemical delivery systems for elemental extraction using the dynamic extraction technique
D. C. Grant
CT Associates, Inc., Excelsior, MN USA
L. Clark and D. Winkelman
Ashland Chemical, Inc., Austin, TX USA
FSI International, Inc., Chemical Management Division, Chaska, MN USA
Motorola Inc., MOS 13, Austin, TX USA
A new method has been developed to measure the rate at which contaminants are extracted from chemical delivery systems. This method, called the Dynamic Extraction technique, is more sensitive, less costly to perform and faster than conventional techniques used to qualify chemical delivery systems. In addition, Dynamic Extraction measures contaminant extraction rate over time thereby allowing calculation of the mass of contaminants added to delivered chemical at any time.
Dynamic Extraction was used to measure extraction of elemental contaminants from six chemical delivery systems installed at Motorola MOS 13 in Austin, Texas. Each system was tested for extraction of 34 elements over a one week period. All of the systems were able to achieve the specification of < 1 ppb of total metals added within three days of initial contact with chemical. Data analysis showed that the systems would add < 0.1 ppb of total metals within 1 month. The systems typically met specification within one day.
CTA Publication #24 in Proceedings of the 13th ICCCS Meeting The Hague, The Netherlands, 1996