摘要 |
A projection lens system that is used to transfer a pattern from a reticle onto a wafer, incorporates a projection optical system that is capable of maintaining the same, or increased performance, as the current projection lens systems, and that achieves excellent aberration correction, has a numerical aperture of at least 0.6, an exposure field area of at least 18.7x18.7 mm or at least 26.45 mm diameter at the wafer plane, and has a total lens thickness to length ratio less than 0.64 and uses 5 or less aspherical lens surfaces.
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