Spectral purity filter, lithographic apparatus including such a spectral purity filter, device manufacturing method, and device manufactured thereby
AssigneeASML Netherlands B.V.
InventorsDerk Jan Wilfred Klunder, Maarten Marinus Johannes Wilhelmus Van Herpen
Life of this patent
Estimating the term…
Abstract
A spectral purity filter includes an aperture, the aperture having a diameter, wherein the spectral purity filter is configured to enhance the spectral purity of a radiation beam by reflecting radiation of a first wavelength and allowing at least a portion of radiation of a second wavelength to transmit through the aperture, the first wavelength being larger than the second wavelength. The spectral purity filter may be used to improve the spectral purity of an Extreme Ultra-Violet (EUV) radiation beam.
Claims26
A lithographic spectral purity filter comprising an aperture, the spectral purity filter being configured to enhance the spectral purity of a radiation beam by reflecting radiation of a first wavelength and allowing at least a portion of radiation of a second wavelength but substantially not of the first wavelength to transmit through the aperture, the first wavelength being larger than the second wavelength.
Dependencies are inferred from the claim text.