Optical mask and method of correcting the same
US5439763A · kind A · utility
15Cited by
4References
24Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 26, 1993 |
| Grant date | Aug 8, 1995 |
| Priority date | — |
| Expiry date | Feb 26, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/30
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical mask for a projection optical system and a method of correcting the mask wherein the mask includes a light intercepting pattern formed on a transparent substrate and a phase shifter for changing the phase of an exposure light provided at predetermined openings of the light intercepting pattern. An etching stopper film which transmits the exposure light is provided between said phase shifter and said light intercepting pattern and for correction of the mask a focused ion beam is utilized for removal of defects by the phase shifter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.