Apparatus and method for phase shift photomasking
US6480263B1 · kind B1 · utility
3Cited by
7References
30Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 16, 2000 |
| Grant date | Nov 12, 2002 |
| Priority date | — |
| Expiry date | Mar 16, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/26
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A photolithographic method and apparatus are disclosed. The apparatus uses a diffraction plate or traditional optical elements to control and shape the light from an illuminator into a Gaussian light intensity distribution for illuminating a phase shift photomask. The Gaussian distribution reduces asymmetrical aberrations of the objective lens that are exaggerated by the phase shift photomask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.