| 摘要 |
PURPOSE:To enhance resolution and depth of focus at the time of projecting and exposing a circuit pattern, etc. CONSTITUTION:An illuminating luminous flux from a light source 1 is made incident on the incident plane 11a of a fly-eye lens 11 by a diffraction grating pattern 5, and a secondary light source image is formed on a position decentering from an optical axis AX and near the outgoing plane 11b of the lens 11. And a reticle 16 is irradiated with the illuminating light from the secondary light source image through condenser lenses 13 and 15, and the image of the reticle pattern 17 is formed and projected on a wafer(photosensitive substrate) 20 by a projecting optical system 18. The outgoing plane 11b of the lens 11 is conjugated with the pupil 19 of the projecting optical system 18. High resolution and the great depth of focus can be attained, and also the uniformity of illuminance distribution on the reticle can be maintained in a good state. |
