| 摘要 |
<p>A refraction projection optical system preferable to a projection exposure apparatus used for lithography process in manufacturing a microdevice such as a semiconductor device. The projection optical system includes a positive front lens group (GF), an aperture stop (AS), and a positive rear lens group (GR), is a both side telecentric optical system, and satisfies the inequalities 0.065<f2/L<0.125 where f2 is the focal length of the rear lens group (GR) and L is the conjugate distance. The projection optical system includes one or more aspherical surfaces (ASP1 to ASP6).</p> |
