The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 25, 2003
Filed:
May. 30, 2001
Johannes Catharinus Hubertus Mulkens, Maastricht, NL;
Paul van der Veen, Eindhoven, NL;
Willem van Schaik, 's-Hertogenbosch, NL;
ASML Netherlands B.V., Veldhoven, NL;
Abstract
In a lithographic projection system using exposure radiation of 157 nm, compositions of gas, e.g. levels of oxygen and water vapor, are measured in regions traversed by the projection beam. The attenuation caused by said gases is predicted and the dose of radiation accumulated during an exposure, the uniformity and angular distribution of radiation energy delivered by said projection beam to a substrate during an exposure is controlled accordingly. The control may comprise a controlled supply of O to a volume traversed by the projection beam so as to effect a controlled attenuation of the projection beam. The O distribution may be non-uniform, e.g. to selectively filter spatially separated diffraction orders or to eliminate non-uniformity's in the projection beam.