Defects in 200mm & 300mm litho modules are a common, yet costly issue.
A major source of defects in lithography modules are fibers & particulates including resist particles that have been left in the track. Contamination that migrates to the scanner or stepper can result in serious defects including difficult to remedy hot spot and defocus issues.
Above: wafer handler End-Effector with hanging lint fiber will cause scratch signature on production wafer.
Reduce Defects at the Start
Foamtec International WCC has created a cleaning BKM/SOP that enables much more thorough cleaning so that Track equipment have higher first pass QUAL rates. As a result, backside wafer contamination is greatly reduced minimizing cross contamination on scanner wafer table.
The SOP is production proven to reduce the need for and harsh wafer table polishing (stoning) PM’s, where a round abrasive stone is used to recondition the surface of the wafer table to help prevent hot spots and defocus issues. A frequent stoning procedure will reduce the lifetime of the expensive wafer table.
Above: Track oven with Foamtec ergonomic cleaning tool
Foamtec’s Track cleaning SOP helps eliminate hot spots, reduce resist and the need to stone the scanner wafer table, resulting in improved uptime greatly reducing defects and cost.
Below, the defect reduction measured with a surface particle counter is evident.
For more information on Foamtec International’s BKM/SOP that will deliver a decrease in litho hot spots, fewer defocus issues, and longer time between stoning and cleaning of the table/chuck in the scanner email us at firstname.lastname@example.org or visit our website at www.foamtecintlwcc.com