Edge-placement accuracy of opaque and clear defect repairs using focused ion beam technology

On the standard Micrion 8000 PM Repair System platform, the repair accuracy for clear defect repair and opaque defect repair is plus or minus 75 nm. Incorporation of a new ion beam column has pushed the repair accuracy for clear and opaque defect repairs to smaller values. This new system can image isolated defects less than 200 nm in size. To characterize the repair accuracy of the system, experiments on edge placement accuracy were performed. This paper presents data on the accuracy of defect repairs using the Micrion 8000 PSM Repair System on Chrome masks. The study specifically looks at the edge placement of opaque defect and clear defect repairs on masks coated with a conductive layer versus masks not coated with a conductive layer. We also explore the edge placement accuracy of the repair due to the directionality of the repair scan. Finally we examine the shape of the distribution function of the repair measurements and also investigate differences in the measured edge placement accuracy of repairs using different measuring techniques.