Laser repair and clean of extreme ultraviolet lithography photomasks

In these tests to examine of the process space for the repair and clean of EUVL photomasks with a laser repair tool, specialized cells were produced to test the effect of variations in the fpIII laser parameters with both carbon and HSQ absorber material pindots on multilayer fields according to DOE methodology. Blank (no pindot) test cells and pindots were inspected both with AFM and PSI RESCAN EUV-actinic lensless metrology both before and after laser processing. This data was then analyzed with DOE, and other, techniques to provide insights into the capability of an optimal fpIII laser process.