摘要 |
A system for microlithography comprises an illumination source; an illumination optical system including, in order from an objective side, (a) a first diffractive optical element that receives illumination from the illumination source, (b) a zoom lens, (c) a second diffractive optical element, (d) a condenser lens, (e) a relay lens, and (f) a reticle, and a projection optical system for imaging the reticle onto a substrate, wherein the system for microlithography provides a zoomable numerical aperture. <IMAGE> |