Multi-mode narrow-band oscillation excimer laser
US4829536A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1987 |
| Grant date | May 9, 1989 |
| Priority date | — |
| Expiry date | Nov 30, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/225
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Specification of an etalon included in a multimode, narrow-band oscillation excimer laster used as a light source for light exposure in photolithography are set to satisfy a relation S.lambda.W.lambda.R.lambda. (u,v)d.lambda..gtoreq..alpha., where .alpha. is an optical transfer function necessary for light exposure of resist according to a reticle pattern, R.lambda.(u,v) is an optical transfer function of monochromatic light for an illuminating system and a reduced-projection lens, W.lambda. is a weight which is applied to a waveform of a power spectrum in an oscillation laser beam at a wavelength .lambda.. Further, an inclination angle .lambda. of the etalon in its normal direction with respect to an optical axis when the etalon is provided between the chamber and rear mirror is set to satisfy a relation .theta.>tan.sup.-1 S/2A, where S is a dimension of a beam at a beam output mirror and A is a distance between the etalon and beam output mirror, and an oscillation linewidth K is set to satisfy relations K=1/.lambda..sub.o [1/{cos (.theta.+.theta.')}-1/cos .theta.} and also K.ltoreq.x, where .lambda..sub.o is a selected wavelength when the beam is directed onto the etalon at a nor…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.