Patent ID: 6128068
Filing Date: 2000-10-03
Classification: G03F

Abstract:
An exposure apparatus for forming an image of a fine pattern having linear features extending in orthogonal first and second directions, said apparatus comprising:an illumination optical system for illuminating the pattern, said illumination optical system comprising means for forming a secondary light source having decreased intensity portions at a center thereof and on first and second axes defined to intersect with each other at the center and defined along the first and second directions, respectively, wherein said secondary light source comprises four sections being distributed in four quadrants defined by the center and the first and second axes;a projection optical system for projecting, on an image plane, an image of the pattern illuminated with light from said secondary light source; anda quartered detector, having four detector sections, for detecting a light quantity distribution of said secondary light source, wherein each of the four detector sections of said quartered detector independently detects a light quantity of a corresponding one of the four sections of said secondary light source.