CATOPTRIC OBJECTIVE MIRROR, BROADBAND OBJECTIVE OPTICAL SYSTEM WITH MIRROR, OPTICAL IMAGING SYSTEM WITH CATADIOPTRIC LENS AND BROADBAND OPTICAL IMAGING SYSTEM HAVING TWO IMAGING PATHS OR MORE

摘要

PROBLEM TO BE SOLVED: To provide a broadband objective optical system and a broadband optical imaging system with two imaging paths or more that allow a use of a much shorter wavelength to improve resolving power as to an imaging optical device for sample inspection and avoid a risk of contaminant diffusion on a wafer.;SOLUTION: An optical system includes an objective optical system with at least four mirrors and a focus adjustment optical system, and the mirrors include an outermost mirror with an aspect ratio equal to or less than 20:1. The focus adjustment optical system includes a refractive optical element. The objective optical system is configured to provide imaging at a numerical aperture equal to or greater than 0.7 and with central obscuration as low as 35%. The objective optical system may include two mirrors or more and one of the two or more mirrors contains a refractive module that seals off a central opening of the outermost mirror. The broadband imaging system may include one objective optical system and two or more imaging paths and the imaging paths are configured to provide imaging at the numeral aperture equal to or more than 0.7 and a field of view equal to or more than 0.8 mm.;COPYRIGHT: (C)2014,JPO&INPIT