| 摘要 |
PROBLEM TO BE SOLVED: To provide a rod integrator type illumination optical system having the high reduction effect of an illumination unevenness and using EUV rays. SOLUTION: A light source (11) emitting EUV rays, a hollow reflection type integrator (15), and an imaging mirror (16) are arranged successively. A secondary light-source forming optical systems (12, 13 and 14) in which a plurality of point sources of light are formed at the incident end of the integrator (15) are arranged between the light source (11) and the integrator (15). According to the group of the point sources of light, the reduction effect of the illumination unevenness is extremely higher than other conditions are the same and only the single point source of light is formed. Consequently, an oblique incident angle to the integrator 15 is set at a comparatively shallow total-reflection angle for reducing the loss of the quantity of light of EUV rays, thus leaving the reduction effect of the illumination unevenness even when the number of reflections in the integrator 15 is decreased. COPYRIGHT: (C)2005,JPO&NCIPI
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