A semi-automated AFM photomask repair process for manufacturing application using SPR6300

For almost a decade Nanomachining application has been studied and developed to repair next generation of photomasks. This technique, based on Atomic Force Microscopy (AFM), applies a mechanical removing of the defects with almost negligible quartz-damage, high accuracy of the edge-placement and without spurious depositions (stain, implanted elements, etc.) that may affect the optical transmission. SII NanoTechnology Inc. (SIINT) is carrying out a joint-development project with DNP Photomask Europe S.p.A. (DPE) that has allowed the installation in DPE of the next generation state-of-the-art AFM based system SPR6300 to meet the repair specifications for the 65 nm Node. Drift phenomena of the AFM probe represent one of the major obstacles for whichever kind of nano-manipulation (imaging and material or pattern modification). AFM drift undermines the repeatability and accuracy performances of the process. The repair methodology, called NewDLock, implemented on SPR6300, is a semi-automated procedure by which the drift amount, regardless of its origin, is estimated in advance and compensated during the process. Now AFM Nanomachining approach is going to reveal properties of repeatability and user-friendly utilization that make it suitable for the production environment.