ILLUMINATING APPARATUS COMPRISING MEANS FOR CONTROLLING TEMPERATURE OF PROJECTION LENS

摘要

PURPOSE: An illuminating apparatus comprising means for controlling temperature of projection lens is provided to control and stabilize temperature of the projection lens by installing the temperature controller around the projection lens. CONSTITUTION: A light source generates light of a single wavelength. The first optic system(12) includes an element for converting the light emitted from the light source to planar light and an aperture for restraining the incident light in order to obtain uniform critical dimension and high resolution. A mask(14) has a predetermined pattern which is printed on a wafer(20). A center of the mask(14) corresponds to a light axis(L) of an exposure apparatus. The second optic system(16) has a reductive projection lens in order to condense the light passing the mask(14) on a predetermined region of the wafer(20). An apparatus(22) for reducing a variation of aberration is installed around the second optic system(16). The apparatus(22) is formed by a thermoelectric element including the first and the second semiconductor material(22a,22b).