| 摘要 |
An illuminating device preferable for a projection exposure apparatus used in a lithography process for fabricating a semiconductor device or a liquid crystal display. Light from a light source is collimated into a parallel beam and directed to a fly-eye lens serving as an optical integrator. A filter (100B) sectioned into filter elements (101A, 102A, 103A) corresponding to the lens elements of the fly-eye lens is disposed on the incidence side of the fly-eye lens. The distribution of transmittance of each filter element (101A, 102A, 103A) is varied substantially continuously so that the distribution of light intensity at the Fourier transformation optical plane for each of the small surfaces constituting the surface to be irradiated is determined independently of each other. |
