Pellicles capable of withstanding the high beam intensity of next generation EUV scanners at the same time maintaining a EUV transmission above 90% and lifetime sufficient to produce 10 000 wafers or more represents a significant challenge from the materials point of view.
In this presentation, pellicles manufactured using free-standing carbon nanotubes (CNT) films less than 20 nm thick were characterized for EUV transmission, scattering, reflectivity, mechanical properties, and capability to stand high intensity (30 W/cm2) EUV radiation in environmental conditions similar to a 600W EUV scanner. Several types of coated CNT films were also tested to increase the lifetime of the pellicles. The EUV transmissions ranged from 98% for uncoated samples to 95% for coated. Scattering up to 4.7 degrees was less than 0.1% for uncoated films and 0.2% for coated one.
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