| 摘要 |
PURPOSE:To increase the depth of focus and the margin of light exposure for an isolated pattern, e.g. a contact hole, by setting the radius at the circular shade part of a pupil filter within a range specific times as large as the radius of the pupil plane of a projection optical system. CONSTITUTION:The shade part S2 serves as a member for holding the circular central shade part S1 at the outer ring shade part S3. The circle P represent the pupil plane of a projection optical system and the radius r2 thereof is proportional to the numerical aperture of the projection optical system. The circular shade part S1 has a radius r1 being set in the range of 0.3-0.5 times of r2. In other words, the ratio of radius r1/r2 is set as follows; 0.3<=r1/r2<=0.5. |
