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:
Dec. 12, 2006
Filed:
Nov. 01, 2004
Romeo I. Mercado, Fremont, CA (US);
Romeo I. Mercado, Fremont, CA (US);
Ultratech, Inc., San Jose, CA (US);
Abstract
A projection optical system suitable for projection photolithography is disclosed. The projection optical system is a modified Wynne-Dyson system capable of imaging a large field over both a narrow and a broad spectral range. The projection optical system includes a positive lens group arranged adjacent to but spaced apart from a concave mirror along the mirror axis on the concave side of the mirror. The system also includes a variable aperture stop so that the system has a variable NA. The projection optical system has two or more common foci within an ultraviolet exposure band and a third common focus in a visible alignment band. A projection photolithography system that employs the projection optical system is also disclosed.