How much time can be saved using the Reticle?
When the PSFM reticle is used to determine and regularly monitor best focus, substantial savings in time can be realized vs. the on-board focus methods. Since focus monitoring can be achieved by running a single wafer lot, productive lithography tool uptime is minimally affected. On-board methods generally require clearing and restarting of the integrated wafer track, which can result in hours of lost productivity. All metrology for PSFM wafers can be done using overlay tools outside of the litho cell.