Productivity of Femtosecond DUV Laser Photomask Repair in a Real World Mask House

A number of new technologies and processes have been developed for deep ultraviolet (DUV) wavelength and femtosecond pulsed laser repair of photomasks. These advances have been shown to improve and extend the repair of both pelliclized and non-pellicilized photomasks for both hard and soft (or nano-particle) in exhaustive testing at the factory and the end-user site. However, even the best testing is only a simulation of what a repair tool will see when brought into full production. The purpose of this work is to review some of the knowledge and experience gained in bringing the repair processes defined with manufactured defects to the more variable defects encountered in the real world. The impact of the repair technology on increases in mask house throughput and decrease in costs will also be compared to other (another laser and an advanced FIB) repair tools.