In modern 300mm wafer fabs, more and more equipment wet cleans are carried out with ultrapure water rather than IPA. The use of UPW is increasing as wafer fabs strive to reduce VOC’s and trace metal contamination levels. Moreover, metal etch and CMP equipment generate process by-products that are not soluble in IPA.
The use of water presents the fab with several challenges, including the need and difficulty in maintaining the purity and cleanliness of UPW which, by its nature, is magnet for contamination.
As the picture below highlights, squirt bottles used in PM’s are subject to many sources of contamination which have been shown to degrade the purity of water.
Squirt bottles are handled by operators whose gloves are quickly contaminated by the very nature of the PM process especially for tools that require the use of Scotch-Brite™ or ScrubPADS™ to remove hardened process by-product. Despite efforts by equipment and micro contamination engineers to install bottle, glove rotation and bottle washing protocols, many audits uncover bottles that should never be used in clean room let alone on an equipment PM.
To address the need to improve contamination control, Foamtec has introduced MiraSAT which is the first cleanroom wiper pre-saturated with Ultrapure Water. MiraSAT is specifically designed and constructed for fab wet cleans and is production-proven, in the most advanced sub-14 nm processes to reduce contamination excursions, test wafer consumption and tool down time.
If you would like more information please view the following links:
MiraSAT Application Note
Scotch-Brite Brand is a trademark of 3M.