Lithography laser with beam delivery and beam pointing control
US6704339B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 2002 |
| Grant date | Mar 9, 2004 |
| Priority date | — |
| Expiry date | Aug 30, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/2258
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention provides a modular high repetition rate ultraviolet gas discharge laser light source for a production line machine. The system includes an enclosed and purged beam path with beam pointing control for delivery the laser beam to a desired location such as the entrance port of the production line machine. In preferred embodiments, the production line machine is a lithography machine and two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality. A pulse stretcher more than doubles the output pulse length resulting in a reduction in pulse power (mJ/ns) as compared to prior art laser systems. This preferred embodiment is capable of providing illumination at a lithography system wafer plane which is approximately constant throughout the operating life of the lithography system, despite substantial degradation of optical components.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.