Use of Nanomachining for Subtractive Repair of EUV and Other Challenging Mask Defects

摘要

This paper introduces nanomachining with the RAVE LLC nm1300 as an effective alternative for subtractive mask repair on a variety of materials. Because the Rave LLC nm 1300 employs a nanomachining strategy for subtractive removals there is essentially no limitation on the types of materials that may be removed. This unique capability makes the RAVE LLC nm 1300 adaptable to performing repairs on EUV, carbon depositions, and contamination that cannot be removed by standard cleaning processes. EUV is widely regarded as the leading candidate for NGL, with beta systems scheduled for delivery in 2005. This technology still faces several critical challenges, some of which relate to defects and Cost of Ownership. In fact, in industry-wide projections, process defects are listed as one of the largest contributors to yield loss (and yield loss is one of the primary drivers of Cost of Ownership). Because the EUV technology utilizes a reflective mask, it presents several challenges to conventional mask repair techniques which to date have not been overcome. This paper introduces nanomachining with the RAVE LLC nm1300 as an effective alternative for subtractive mask repair of EUV mask defects. In addition, this paper will demonstrate how the Rave LLC nm 1300 nanomachining process can be utilized to repair masks that do not meet specification due to misplaced carbon depositions or 'non-removable' contamination covering critical geometries.