Patent attributes
The present invention relates to a high numerical aperture exposure system having a wafer. The exposure system in the present invention includes a beam-splitter, a reticle, a reticle optical group, where the reticle optical group is placed between the reticle and the beam-splitter, a concave mirror, a concave mirror optical group, where the concave mirror optical group is placed between the concave mirror and the beam-splitter, a fold mirror, where the fold mirror is placed between the beam-splitter and the wafer, and a wafer optical group, where the wafer optical group is placed between the beam-splitter and the wafer. In the present invention, a beam of light is directed through the reticle and the reticle optical group to the beam-splitter, then it is reflected by the beam-splitter onto the concave mirror. Concave mirror reflects the light onto the fold mirror through the beam-splitter. Fold mirror reflects the light onto the wafer through the wafer optical group. The present invention forms an intermediate image between the fold mirror and the wafer optical group. Furthermore, in an embodiment an aperture stop can be placed between the concave mirror optical group and the concave mirror.
