The measurement of organic and inorganic contaminants in photolithography purge gas is validated to below a 1 part-per-trillion lower detection limit using a Cold Trap concentrated method. To investigate the contaminant loading history into a purifier during its lifetime, a Purifier Information Retrieval Service (PIRS) is developed with measurement sensitivity below 0.01 microgram. This method is validated by accurately loading and unloading known challenges of contaminants into a GateKeeper purifier. The result indicates that if a purifier is operating at 100% duty cycle and 1 slm for 1 year, an annual quantitative measurement average of the impurites in the process gas of less than 5 part-per-quadrillion can be achieved.

Date Published: 2 June 2003
PDF: 11 pages
Proc. SPIE 5038, Metrology, Inspection, and Process Control for Microlithography XVII, (2 June 2003); doi: 10.1117/12.488483

Published in SPIE Proceedings Vol. 5038:
Metrology, Inspection, and Process Control for Microlithography XVII
Daniel J. Herr, Editor(s)