Laser-based system for the total repair of photomasks
US4727234A · kind A · utility
54Cited by
3References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1986 |
| Grant date | Feb 23, 1988 |
| Priority date | — |
| Expiry date | Jun 27, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/72
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An apparatus for repairing both clear and opaque defects in a photomask having a metal film pattern on a glass plate in which a visible laser light source is pulsed at selected frequencies to direct an optically focused laser beam into a gas sealed cell containing a mask. At one frequency, the laser pulses ablate opaque mask defects. At another frequency, and with the cell filled with a metal bearing gas, the laser beam causes thermal decomposition of the gas and deposition of metal to cure clear defects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.