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:
Jun. 17, 2008
Filed:
Jun. 15, 2006
Arie Johan Van Der Sijs, Veldhoven, NL;
Haico Victor Kok, Eindhoven, NL;
Arie Johan Van Der Sijs, Veldhoven, NL;
Haico Victor Kok, Eindhoven, NL;
ASML Netherlands B.V., Veldhoven, NL;
Abstract
A radiation distribution measurement system for measuring a phase distribution of a beam of radiation and/or a pupil distribution of a projection system includes a transparent carrier plate, a grating and/or a pinhole configured at a first side of the transparent carrier plate, and a camera at an opposite side of the transparent carrier plate. The measurement system also includes a radiation filter between the transparent carrier plate and the camera, with a transmissivity that is lowest at the center of the filter and gradually and concentrically increases towards the outside of the filter. By placing the filter with its specific transmissivity, the difference in intensity across the wave front sensor(i.e. the gradient in intensity) is compensated. The intensity of the light incident on the camera is made more uniform resulting in an improved performance of the measurement system.