BEAM-SPLITTER OPTICS DESIGN THAT MAINTAINS AN UNFLIPPED UNMIRRORED IMAGE FOR A CATADIOPTRIC LITHOGRAPHIC SYSTEM

摘要

The present invention relates to a reticle optical group, the beam splitter, the aspherical mirror, the baffle plate, the folding mirror and a semiconductor wafer having an optical system, a catadioptric group. Reticle optical group, the beam splitter and the semiconductor wafer optical group are placed on the same beam axis and is different from aspheric mirror and folding mirror axis. The light is reflected by the aspheric mirror through the beam splitter by the image pattern on the reticle. Aspheric mirror reflects the beam back to the folding mirror through the optical splitter. Folding mirror reflects the light back to the beam splitter. The beam splitter reflects the light to a semiconductor wafer optical group. A plurality of quarter-phase plate may change the polarization of light incident on the optical path is arranged between the optical element of the present invention. This prevents the light that before passing through the semiconductor wafer optical group, any background scattered light caused by internal reflections within the beam splitter passes through the baffle plate is joined to the semiconductor wafer optical group. In another embodiment, the spacer plate is inserted into the beam splitter. Spacer plate creates an offset between reticle optical group beam axis and semiconductor wafer optical group beam axis. This reduces direct passage of light from reticle optical group to semiconductor optical group. ; Reticle optical group, the beam splitter, the aspherical mirror, the baffle plate, a catadioptric lithographic system