US Patent 7148953 Apochromatic unit-magnification projection optical system
Patent 7148953 was granted and assigned to Ultratech on December, 2006 by the United States Patent and Trademark Office.
All edits
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.
US Patent 07148953 Apochromatic unit-magnification projection optical system US Patent 7148953 Apochromatic unit-magnification projection optical system
US Patent 07148953 Apochromatic unit-magnification projection optical system
Find more entities like US Patent 7148953 Apochromatic unit-magnification projection optical system
