Laser plasma X-ray source
US5089711A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 13, 1990 |
| Grant date | Feb 18, 1992 |
| Priority date | — |
| Expiry date | Dec 13, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/005
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A laser plasma X-ray source for use in photolithography is disclosed wherein an electro-optical shutter is used to trim the output pulse from a master oscillator to a desired duration. The pulse is then split into several pieces which travel along various optical delay paths so that the pieces pass sequentially through a laser power amplifier. After amplification, the pieces are reassembled and then focussed at the plasma target. In a first embodiment, polarization and angle coding methods are used to distinguish each pulse piece at it travels along the delay paths. In a second embodiment, polarization coding is replaced by additional angle coding transverse to the plane of the angles of the first embodiment. An expander/reducer lens assembly is used in both embodiments to reduce the angles between the beam paths and allow more beams to fit closely to the laser amplifier gain region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.