Solid-state laser system for ultra-violet micro-lithography
US5940418A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 22, 1996 |
| Grant date | Aug 17, 1999 |
| Priority date | — |
| Expiry date | Nov 22, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/1636
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A solid state laser systems for generating highly monochromatic laser radiation at wavelengths of interest for advanced micro-lithography, particularly 248 nanometer and 193 nanometer wavelengths. At least one Nd:YAG laser produces a 1,064 nm laser beam consisting of narrow-linewidth pulses of infra-red laser radiation having a pulse duration of less than 30 nanoseconds, at a pulse rate preferably in excess of 500 pulses per second with pulse energy greater than 20 millijoules. This radiation is frequency doubled and frequency tripled to produce 532 nm and 355 nm pulsed laser beams. These beams are then further optically processed to generate the ultra-violet wavelength for micro-lithography at either 248 nm or 193 nm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.