DIFFRACTIVE OPTICS, DIOPTRIC ELEMENT, ILLUMINATING OPTICAL SYSTEM, EXPOSURE SYSTEM AND EXPOSURE METHOD

摘要

An illuminating optical system capable of various good multi-pole illuminations with a restricted loss in light quantity by using a diffractive optics for forming a substantially uniform multi-pole-form illumination distribution on an illumination pupil plane. An illumination optical system for illuminating surfaces to be illuminated (13, 15). Diffractive optics (6 (61-69)) are provided for converting an incident light flux into a light flux having a specified sectional shape in order to form a secondary light source having a multi-pole-form light intensity distribution on an illumination pupil plane. Diffractive optics (6) have patterns obtained by densely arranging patterns picked up from virtual, ring-like diffractive optic patterns in conformity with a specified azimuth angle range.