| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a six-mirror reflective projection optical system constituted so that it is applicable to EUV lithography, and it has a high NA, and also, the maximum effective diameter of the mirror and the whole length of the optical system are made small and it has an improved image forming performance, and to provide an exposing device. <P>SOLUTION: As for the reflective projection optical system for projecting a reduced size of a pattern on an object surface onto an image plane, the optical system is provided with six or more mirrors functioning as an image forming system for forming an intermediate image and for successively reflecting the light from the object surface to the image plane, the exit pupil of the intermediate image is positioned between the object surface and the image plane, and also, provided that the numerical aperture on the image plane side is expressed by NA, an angle formed by the principal ray of each viewing angle and the optical axis at the exit pupil position is≤sin<SP>-1</SP>NA. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
