Catadioptric lithography system and method with reticle stage orthogonal to wafer stage
US6757110B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 2002 |
| Grant date | Jun 29, 2004 |
| Priority date | — |
| Expiry date | May 29, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70225
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention relates to a lithography apparatus using catadioptric exposure optics that projects high quality images without image flip. The lithography apparatus includes a reticle stage, a wafer stage, and a catadioptric exposure optics located between the reticle stage and the wafer stage. The catadioptric exposure optics projects an image from the reticle stage onto the wafer stage. The projected image has the same image orientation as the image from the reticle stage. In other words, the catadioptric exposure optics does not perform image flip. The reticle stage lies on a first plane and the wafer stage lies on a second plane, where the first plane is orthogonal to the second plane. In another embodiment of the present invention, the catadioptric exposure optics projects an even number of reflections. The projected image is of high precision and lacks aberrations such as perspective warping and obscured areas. The invention can be combined with a dual wafer stage and with a dual isolation system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.