AIMS-fab SPEC for defect repair and better repair profile

For current mask defect repair, depending only on an inspection metrology tool (KLA-SLF77) to judge wafer printability is not enough. Many mask makers and users are turning to simulation-based photomask qualification to reduce unnecessary repairs and confirm defect repair. Using programmed defects of known size, phase, and location, we fabricated binary and Att PSM test masks to perform the repair. Utilizing Carl Zeiss’ Aerial Image Measurement System (AIMS-fab), we compared reticle simulation results to actual wafer image prints and then established a criteria SPEC as the core judgment rule. The investigation shows for binary L/S layout, the better repair profile received a wider ED-window for the wafer process. For Att PSM contact layout, the proper depth of quartz etching for smaller miss-contact was also demonstrated.