| 摘要 |
The illuminating optical system is divided into a first portion including movable blades moving during exposure, and a second portion not containing a movable portion moving over the movable blade during exposure. The second portion is installed on the exposure main portion, and the first portion, separately from the exposure main portion. The frames configuring the first and the second optical units, the second optical unit having optical elements of a smaller movable amount than the movable amount of the movable blades, are relatively displaceably connected via the bellows-shaped member. The frames configuring the second optical units are fixed to each other via the O-ring suppressing relative displacement. As a result, the effect of vibration of the illuminating optical system during exposure on the main portion can be reduced. Upon purging nitrogen gas or the like in the space interior of the frame and the space between adjacent frames, the degree of air-tightness and chemical cleanliness is improved, consequently improving the exposure accuracy.
|
