Patent ID: 7317583

Claim:
A high numerical aperture projection system for projecting an image of a reticle onto a wafer, comprising: a beam-splitter; a reticle optical group; a quarter-wave plate between the reticle and said beam-splitter; a concave mirror; a concave mirror optical group, wherein said concave mirror optical group is between said concave mirror and said beam-splitter; a fold mirror; a wafer optical group; wherein a beam of light is directed through the reticle and said reticle optical group to said beam-splitter, then reflected by said beam-splitter onto said concave mirror, then reflected by said concave mirror onto said fold mirror through said beam-splitter, and is reflected by said fold mirror onto the wafer through said wafer optical group, the beam of light being directed to said beam-splitter having an s-polarization state and through said beam-splitter having a p-polarization state; wherein an intermediate image is formed between said beam-splitter and said wafer optical group when the beam of light passes through the system, the intermediate image being a real image of the image from the reticle.