No abstract

No abstract

We report on the development of a new mask inspection technology that makes total inspection faster and less costly. The new technology adopts a method of selecting a defect detection sensitivity level for every local area, defined by factors such as defect judgment algorithm and defect judgment threshold. This approach results in a reduction of pseudodefect count leading to shorter inspection and review time. Selected defect detection sensitivity levels for every local area are extracted from a database of Mask Data Rank (MDR) that is based on the design intent from the design stage, and/or on a pre-analysis of inspection pattern data. The proposed system also executes a printability verification function, not only for the mask defect regions but also for specific portions where high Mask Error Enhancement Factor (MEEF) is determined. It is necessary to ascertain suppression of pseudo-defect detection for extremely complicated masks such as masks with Source-Mask Optimization (SMO). This work reports on the new mask inspection system.

No abstract

We have developed a deep ultraviolet die-to-database inspection system MC-3500 for the 130 nm node and beyond. The system involves comparison of a mask image scanned at a wavelength of 257 nm and a reference data calculated from complex amplitude of objects with 200 Mpixel/s throughput. An approximation of Hopkins formulation in the region of a large partial coherence factor gives a nonlinear filtering scheme for embedded attenuated phase shift mask ͑EPSM͒. The nonlinear filtering was evaluated for intensity fidelity of the reference image using comparison with Hopkins formulation. Evaluation results show that phase optimization is effective in eliminating excessive image ringing and the minimum feature size to maintain fidelity is found to be over 3 pixels. The technique is promising in applications to high-transmission EPSM.