Scanning lithography system haing double pass Wynne-Dyson optics
US5757469A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 22, 1995 |
| Grant date | May 26, 1998 |
| Priority date | — |
| Expiry date | Mar 22, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70358
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A small field scanning photolithography system has a double pass Wynne-Dyson optical system which provides an erect, non-reverted, unmagnified image. An optical path through the system passes from an object, reflects off an input reflector, passes through a first quadrant of a lens, reflects off a concave mirror, passes through a second quadrant of the lens into folding optics where an intermediate image forms, passes from the folding optics through a third quadrant of the lens, reflects off the concave mirror a second time, passes through a fourth quadrant of the lens, and finally reflects off an output reflector to a plane where a final image forms. Typically, the input and output reflectors and the folding optics are prisms. A field stop may be provided in the folding optics where the intermediate image forms. Magnification adjusting optics can be added to the input and output prisms or to the folding optics. The magnification adjusting optics forms two narrow meniscus air gaps which are equal size for unity magnification. Narrowing one air gap and widening the other air gap changes magnification slightly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.