Study Of Defect Verification Based On Lithography Simulation With A Sem System

In a Photomask manufacturing process, mask defect inspection is an increasingly important topic for 193nm optical lithography. Further extension of 193nm optical lithography to the next technology nodes, staying at a maximum numerical aperture (NA) of 1.35, pushes lithography to its utmost limits. This extension from technologies like ILT and SMO requires more complex mask patterns. In mask defect inspection, defect verification becomes more difficult because many nuisance defects are detected in aggressive mask features. One of the solutions is lithography simulation like AIMS. An issue with AIMS, however, is the low throughput of measurement, analysis etc.