EUV reticle pattern repair experiments using 10 KeV neon ions

摘要

Any potential lithography must demonstrate an industrially-compatable reticle pattern repair process before the lithographic process can be seriously considered for production. Repair of clear defects on ELTV reticles (i.e., regions on the mask which are reflective and should be non-reflective) requires the deposition of a thin layer of absorbing material. This process has been demonstrated in commercially available tools which were originally developed to repair proximity-print x-ray lithography masks. However, the repair of opaque defects (i.e., the recovery of reflectivity from regions on the reticle covered with an absorber) is more difficult. Opaque defect repair requires the removal of the absorber layer without damaging the underlying multilayer, a process which could degrade the mirror reflectivity. While opaque defect repair processes have been demonstrated in a research environment these processes may not be commercially suitable. We are developing reticle repair processes that will be consistent with a commercially available repair tool. In this paper, we report on our first results.