摘要 |
<p>An aligner in which exposure light from an exposure light source (100) is applied to a reticle (R) through an illuminating optical system (200) and its pattern image is projected onto a photosensitive wafer (W) through a projection optical system (300), and which is equipped with a gas supply device (150) for filling spaces (310, 311) formed between optical elements in a lens barrel (LB) housing the projection optical system (300) therein with an inert gas, pressure sensors (PS2, PS3) for sensing the pressures in the spaces, and optical performance adjustment devices (303, 304) for adjusting the optical performance of the projection optical system (300). The optical performance adjustment device refers to a device for adjusting a distance between a pair of the optical elements or a device for adjusting a pressure in a space between the optical elements.</p> |