Critical dimension guarantee for the next generation photomasks with critical dimension scanning electron microscope

摘要: Advanced critical dimension (CD)-scanning electron microscope was evaluated as a photomask CD guarantee tool. Measurement repeatability 2.3 nm (3σ) for each measurement, and reproducibility (range of average value in five days) 3 nm. The contamination effect by measuring isolated Cr line space patterns. on measured estimated 0.02 nm/scan (reticle scale) from the result 500 scans at same position. This quite different results aerial image approximately 0.3 MSM100 (λ=248 nm) exposure (λ=193 nm). difference between these two evaluation probably due to transmittance reduction beam scanning area quartz substrate. consideration supported atomic force microscopy simulation results. There no degradation measurement shift caused charging most severe condition (0.4 μm dot, global coverage 20%, local 0.05% under magnification 88 000×).Advanced s...