| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a reflective optical system applicable, for example, to an exposure apparatus using EUV light, in which the reflective optical system is an imaging optical system of opposite pupil type with an entrance pupil distance secured to be relatively large and, in addition, with an aberration satisfactorily corrected. <P>SOLUTION: The imaging optical system of an opposite pupil type, which is applicable to an exposure apparatus, includes six reflecting mirrors and forms an image of a first plane on a second plane. An entrance pupil of the imaging optical system is positioned on an opposite side of the imaging optical system across the first plane. PD, which denotes a distance measured along an optical axis AX between the entrance pupil and the first plane, TT, which denotes a distance measured along the optical axis between the first and the second plane, and R (rad), which denotes an angle of incidence of a principal ray incident on the first plane, meet a condition, -14.3<(PD/TT)/R<-8.3. <P>COPYRIGHT: (C)2011,JPO&INPIT |
