摘要 |
An illumination system and condenser for use in photolithography in the extreme ultraviolet wavelength region having a first non-imaging optic element collecting electromagnetic radiation from a source and creating a desired irradiance distribution and a second non-imaging optic element receiving the electromagnetic radiation from the first non-imaging optic element and redirecting and imaging the electromagnetic radiation. The electromagnetic radiation emanating from the second non-imaging optic element is suitable for being received by other conventional optical surfaces to provide a desired irradiance distribution with a desired angular distribution and desired shape. Facets are used to provide the desired illumination over the desired illumination field. Reflective facets may be placed on the second non-imaging optic, which can reduce the number of mirrors and increase efficiency. The condenser and illumination system are used in combination with a projection optic to project the image of a reticle or mask onto a photosensitive substrate, such as a semiconductor wafer used in the manufacture of electronic or semiconductor devices. The condenser of the present invention provides an efficient condenser in a compact package and provides desirable illumination properties for imaging relatively small feature sizes less than 0.13 microns.
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