Method and lens arrangement to improve imaging performance of microlithography exposure tool
US6069739A · kind A · utility
24Cited by
16References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1998 |
| Grant date | May 30, 2000 |
| Priority date | — |
| Expiry date | Jun 30, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S359/90
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A technique for introducing variable phase delay across portions of a spatially coherent light beam, such as a laser, without changing the focal length of the portions of the beam. A fly's-eye lens array is utilized to distribute the light for a more uniform illumination, but different length air gaps are introduced in the lens elements to provide a variable delay of portions of the beam. In a second scheme, a set of prisms is positioned in the path of the laser beam, in which the shape of the prism introduces variable phase delay across the cross-section of the beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.